by admin | May 17, 2012 | Home Improvement
Expansion of the Home Buyers’ Plan (HBP)
To provide first-time homebuyers with greater access to their RRSP savings to purchase or build a home, the Government of Canada has increased the Home Buyers’ Plan withdrawal limit to $25,000 from $20,000 per person for withdrawals made after January 27, 2009.
To obtain more information on the First-Time Home Buyers’ Tax Credit and the Home Buyers’ Plan, call 1-800-O-Canada or visit the Canada Revenue Agency website at www.cra.gc.ca.
Looking for More Homebuying Information?
When it comes to buying your home, nothing is more valuable than peace of mind. That’s why for more than 60 years, CMHC has shared a wealth of knowledge and housing expertise to contribute to a positive homeownership experience for Canadians. Browse through our wealth of homebuying information. You’ll find everything you need, from homebuying videos, to mortgage calculators, to home hunting worksheets.
CMHC also provides mortgage loan insurance that enables you to buy a home with a minimum down payment of 5%” — with interest rates comparable to those with a 20% down payment. Obtain a 10% premium refund and extend the amortization period without a premium surcharge when using CMHC-insured financing to purchase an eligible energy-efficient home. This can add up to savings of $1,688 for a typical $250,000 mortgage with a 5% down payment amortized over 35 years. Ask your mortgage professional about CMHC.
by admin | Jan 17, 2012 | Home Improvement, Home Repair, Saftey
Carbon Monoxide
The presence of carbon monoxide (CO) in our homes is dangerous. So, how can you protect your family from carbon monoxide? How do you choose the right CO detector for your home? The first step is to make sure that carbon monoxide never enters your home. The second step is to install at least one CO detector in your home.
This About Your House answers often-asked questions about carbon monoxide to help you make the right decision to make your home safe.
What Is Carbon Monoxide?
Carbon monoxide (CO) is a colourless and odourless gas. Because you can’t see, taste or smell it, it can affect you or your family before you even know it’s there. Even at low levels of exposure, carbon monoxide can cause serious health problems. CO is harmful because it will rapidly accumulate in the blood, depleting the ability of blood to carry oxygen.1
Where Does Carbon Monoxide Come From?
Carbon monoxide is a common byproduct of the combustion (burning) of fossil fuels. Most fuel-burning equipment (natural gas, propane and oil), if properly installed and maintained, produces little CO. The byproducts of combustion are usually safely vented to the outside. However, if anything disrupts the venting process (such as a bird’s nest in the chimney) or results in a shortage of oxygen to the burner, CO production can quickly rise to dangerous levels.
The burning of wood, kerosene, coal and charcoal produces CO. Gasoline engines produce CO. CO production is at a maximum during the startup of a cold engine. Starting, then idling, your car or gas mower in the garage can be dangerous. The fumes that contain CO can enter a home through connecting walls or doorways and can quickly rise to dangerous levels.
How Can I Eliminate Sources of Carbon Monoxide in My Home?
The most important step you can take to eliminate the possibility of CO poisoning is to ensure that CO never has an opportunity to enter your home. This is your first line of defence. Review this list to minimize the risk of CO in your home.
- Have a qualified technician inspect and clean fuel-burning appliances yearly, before the cold weather sets in, to ensure they are in good working order.
- Have a qualified technician inspect chimneys and vents yearly for cracks, blockages (e.g., bird’s nests, twigs, old mortar), corrosion or holes.
- Check fireplaces for closed or blocked flues.
- Check with a qualified technician before enclosing heating and hot water equipment in a smaller room, to ensure there is adequate air for proper combustion.
- If you have a powerful kitchen exhaust fan or downdraft cooktop, have a qualified technician check that its operation does not pull fumes back down the chimney.
- Never use propane or natural gas stove tops or ovens to heat your home.
- Never start a vehicle in a closed garage; open the garage doors first. Pull the car out immediately onto the driveway, then close the garage door to prevent exhaust fumes from being drawn into the house.
- Do not use a remote automobile starter when the car is in the garage; even if the garage doors are open.
- Never operate propane, natural gas or charcoal barbecue grills indoors or in an attached garage.
- Avoid the use of a kerosene space heater indoors or in a garage. If its use is unavoidable provide combustion air by opening a window while operating. Refuel outside after the unit has cooled.
- Never run a lawnmower, snowblower, or any gasoline-powered tool such as a whipper snipper or pressure washer inside a garage or house.
- The use of fossil fuels for refrigeration, cooking, heat, and light inside tents, trailers, and motorhomes can be very dangerous. Be sure that all equipment is properly vented to the outside and use electric or battery-powered equipment where possible.
- Regularly clean the clothes dryer ductwork and outside vent cover for blockages such as lint, snow, or overgrown outdoor plants.
- Reduce or eliminate the use of fondue heaters indoors.
- If you live close to a road with heavy traffic, outdoor carbon monoxide levels can affect your indoor air quality, especially during rush hour. Such levels should not set off a CO alarm, but slightly elevated CO levels might be observable on some types of CO detectors with a digital display.
Carbon Monoxide Detectors
Are They Really Necessary?
If you take the actions above, you greatly reduce your risk of CO poisoning. But unanticipated dangerous incidents may still occur despite your best efforts to avoid CO. The installation of at least one CO detector in your home is a good safety precaution and in some municipalities, it is the law. A detector might be your second line of defence, but it is necessary. You should have one in your home today.
How Do CO Detectors Work?
There are three basic types of CO sensors — metal oxide, biomimetic and electrochemical. Note that while there may be performance differences between these technologies, all detectors are tested and approved for their operation. The retail cost of a detector will generally relate to the number of features included and its warranty conditions.
Metal-oxide-semi-conductor (MOS)
This is the original technology for detecting CO. Heated tin oxide reacts with CO to determine the levels of the toxic gas. There is no need to remember to check batteries as units must be connected to house power. Models that offer up to 20 hours of battery backup are available.
Biomimetic
Biomimetic detectors have gel-coated discs that darken in the presence of CO and the colour change sounds an alarm. This technology is less expensive and can be battery operated.
Electrochemical
In this type of detector, a chemical reaction with CO creates an electrical current that sets off an alarm. Electrochemical detectors are highly sensitive and offer accurate readings at all CO levels. Most units come with a continuous digital readout and a memory feature that allows you to check past CO levels. This technology offers a fast reset time. Most units sound an alert when the sensor needs to be replaced.
What Features Should I Look for When Purchasing a CO Detector?
Most CO detectors are designed to give an alarm when CO levels reach a high level in a short time. However, health agencies advise that long-term, low-level exposure is also of concern, especially for the unborn and young children, the elderly and those with a history of heart or respiratory problems.1 Detectors that can display both high and low levels are more expensive but they do provide greater accuracy and more information.
Here are some features to consider when purchasing a CO detector:
- Look for a detector that is listed with the Canadian Standards Association (CSA) standard. The logos of the testing agency will be on the product.
- Choose a detector with a memory if you want to monitor long-term, low-level exposure and short-term, high-level exposure. Even though product standards do not allow manufacturers to display low levels of CO, these units monitor and store this information. Peak levels, no matter what the level of concentration, can be viewed by pressing a button.
- Battery-operated units allow detector placement in the most convenient location. However, any battery-operated device requires the user’s diligence in replacing worn-out batteries.
- Do not connect plug-in units to an electrical outlet that is controlled by a wall switch.
- No detectors will operate properly forever. Replace them at least every five years, unless the manufacturer specifies a shorter or longer life. Eventually, manufacturers may be required to print expiry dates on their CO detectors. This will ensure that you are purchasing an up-to-date product with a full sensor life.
Detector Sensitivity Issues
The standards organizations of Canada (CSA) and the United States (Underwriters Laboratories or UL) have coordinated the writing of CO standards and product testing. The standards as of 2010 prohibit showing CO levels of less than 30 ppm on digital displays. The most recent standards also require the alarm to sound at higher levels of CO than with previous editions of the standard. The reasoning behind these changes is to reduce calls to fire stations, utilities and emergency response teams when the levels of CO are not life threatening. This change will also reduce the number of calls to these agencies due to detector inaccuracy or the presence of other gases. Consequently, new alarms will not sound at CO concentrations up to 70 ppm. Note that these concentrations are significantly in excess of the Canadian health guidelines.
Detectors with a digital display and a “history” option can provide the true CO concentrations in a house. A low-level display would be useful for people with existing respiratory problems or for those who like to spot evolving problems, rather than having to wait for the situation to become serious. Low-level CO detection products are becoming commercially available. They will not be certified to CSA or UL standards, as these standards currently prohibit low-level displays.
Where Do I Put a CO Detector?
Most manufacturers specify where you should locate their CO detector. In general, the best place to put the detector is where you will hear it while sleeping. CO is roughly the same weight as air and distributes evenly throughout a room, so a detector can be placed at any height in any location, as long as its alarm can be heard. Additional units could be installed in several other locations around the home, such as a child’s bedroom; check the following list before installing.
To avoid both damage to the unit and to reduce false alarms, do not install CO detectors:
- in unheated basements, attics or garages
- in areas of high humidity
- where they will be exposed to chemical solvents or cleaners, including hair spray, deodorant sprays, etc.
- near vents, flues or chimneys
- within 2 m (6 ft.) of heating and cooking appliances
- near forced- or unforced-air ventilation openings
- within 2 m (6 ft.) of corners or areas where natural air circulation is low
- where they can be damaged, such as an outlet in a high traffic area
- where directly exposed to the weather.
Testing Your CO Detector
Most CO detectors have a test button that should be pressed once a week to confirm that the device is in operation. Detectors with displays can be tested with a known source of CO such as smoke from an incense stick. Hold the CO source about 20 – 25 cm (8 – 10 in.) away and watch the digital display respond to the presence of even a small amount of CO, but an alarm will most likely not sound with this test.
There are CO detector test kits available, where CO detectors are sold, that provide a vial containing a high level of CO (1,000 ppm) and a plastic tent to house the unit during the test. This test only proves that your detector will sound an alarm with a very high level of CO.
What Do I Do if I Hear the Carbon Monoxide Detector Alarm?
Do not ignore the CO detector’s alarm if it sounds. Treat each alarm as serious and respond accordingly. CO detectors are designed to sound an alarm before a healthy adult would feel any symptoms. Infants, the elderly and those with respiratory and heart conditions are at particular risk and may react to even low levels of CO poisoning.1
Response to an Obvious Source of CO
If your detector sounds an alarm and you have an obvious source of CO, such as an unvented kerosene heater:
- evacuate the house, including pets and do a head count
- if anyone is suffering from flu-like symptoms, call 911
- remove or turn off the source
- ventilate the house
- reset the alarm
- do not re-occupy the house until the alarm ceases
- take steps to avoid this situation in the future.
Response to an Unknown Source of CO
If your CO detector is sounding an alarm and there is no obvious source of CO:
- evacuate the house, including pets and do a head count
- if anyone has flu-like symptoms, call 911; if there are no health problems, call your gas utility, heating contractor or the fire department to have your house tested
- if you live in a single-family home: do not ventilate your home, turn off fuel-burning appliances or reset your CO detector prior to someone testing your home. Many CO alarm calls have been classified as “false alarms” because the homeowner had ventilated the home and turned off the equipment before firefighters or technicians could measure the CO levels and find the source
- if you live in a duplex, row house, apartment, or otherwise attached house, do ventilate the house and turn off fuel-burning appliances. In this case, the safety of your neighbours is more important than trying to find the CO source
- have a qualified service technician inspect and repair all fuel-burning appliances, if they are identified as being the CO source
- do not re-occupy the house unless those who tested the house inform you that the danger is over.
Symptoms of Carbon Monoxide Poisoning2
Be sure that all members of your family know the symptoms of CO poisoning:
Mild Exposure
Flu-like symptoms such as headache, running nose, sore eyes, etc.
Medium Exposure
Drowsiness, dizziness, vomiting. The sense of disorientation and confusion may make it difficult for some victims to make rational decisions like leaving the home or calling for assistance.
Extreme Exposure
Unconsciousness, brain damage, death.
Continued Low-level Exposure to CO
While this may be not lead to observable symptoms, you should still avoid such exposure.
Table 1 — Carbon monoxide concentrations and their effects
| CO concentration in parts per million (ppm) |
Effects |
| 0 – 2 |
Normal conditions in and outside Canadian houses. |
| 10 |
Recommended exposure limit over a 24-hour period.3 |
| 25 |
Recommended exposure limit over a 1-hour period.3 |
| 30 |
CO detectors are not allowed to sound alarm unless this concentration is maintained for more than 30 days.2 |
| 70 |
CO detectors must sound alarm within 1 to 4 hours.2 |
| 150 |
CO detectors must sound alarm within 10 to 50 minutes.2 |
| 200 |
Slight headache, fatigue, dizziness and nausea after 2 to 3 hours. CO detector alarm must sound within 35 minutes.4 |
| 400 |
CO detectors must sound alarm within 4 to 15 minutes.2 |
| 800 |
Dizziness, nausea and convulsions within 45 minutes, death within 2 to 3 hours.4 |
| 1,600 |
Death within 1 hour.4 |
| 13,000 |
Danger of death after 1 to 3 minutes.4 |
1 Canada. Health Canada,
Exposure Guidelines for Residential Indoor Air Quality (Ottawa: Ministry of Supply and Services Canada, 1989).
2 Canadian Standards Association, CAN/CSA 6.19-01: Residential Carbon Monoxide Alarming Devices (Canada: Canadian Standards Association, 2001).
4 T. H. Greiner, Carbon Monoxide Poisoning (AEN-172) (Ames: Iowa State University of Science and Technology, 1997).
Last revised: 2011
by admin | Jan 17, 2012 | Blog, Home Improvement
by admin | Jan 10, 2012 | Blog, Home Improvement
Removing Ice on Roofs
The 1998 Ice Storm
The ice storm that hit eastern Canada in January, 1998 was a laboratory for concentrated research into severe ice accumulation on roofs.
Removing ice on roofs describes some of the techniques developed from the research for dealing with extensive roof icing and ice dam problems.
Please note: Some of these techniques are for skilled tradespeople only. No ice problem on your roof is serious enough to risk broken bones — or worse.
The balance between removing ice and damaging the roof
Thick ice is hard to remove.You must decide if trying to remove it will cause more damage than leaving it on the roof. Tools, such as hammers, shovels, scrapers, chain saws, and devices such as shoes with ice spikes can damage roofing materials or the structure below. Chemical de-icers can discolor shingles, break down membranes and corrode flashings and drains. De-icers can also damage plants on the ground.
What to do in an ice storm emergency
First: Observe and evaluate the situation every day. Is the ice causing a structural problem? Is there water damage? Do you have to do anything?
Second: Evaluate your capabilities and limits. Do you have the equipment, the agility and the help to work safely and efficiently? If you don’t, get professional help before the situation becomes urgent.
Third: To prevent damage, do as little as possible.Total clearing has the greatest potential for damage to the roof and to people and property below. Often, clearing dangerous overhangs and icicles and making drainage paths is enough.
Recommended Procedures for Sloped Roofs
When is there a problem?
The lower the slope, the greater the weight problem. During the ‘98 ice storm many flat roofs had 15 cm (6 in.) of solid ice, while most sloped roofs had little more than 5 cm (2 in.). Most of the ice collected at roof junctions, behind obstructions such as chimneys or skylights, and at roof edges. Drainage, not removal, solved the problem in most cases.
The information in Signs of Stress will help you decide if weight is causing problems on your roof. If your house doesn’t show signs of stress, then there is no need to remove all the ice.
Drainage
On a sloped roof, your goal is to make drainage paths through the ice on the lower edge of the roof. That’s where most ice dam and water back-up problems occur. Always shovel off loose snow to expose the ice.
If you have power and electric heating cables, making drainage paths is fairly easy. Attach loops of electrical roof de-icing cables to one or more long boards. With ropes tied to the board and thrown over the roof, pull the board up beyond the ice dam, letting the electrical loops hang slightly off the edge of the roof (see Figure 1).
Figure 1: Cables secured to roof
If you want drainage paths higher on the roof, use bundled loops of electrical de-icing cables. They can be drawn high on the roof. Make sure that they hang off the edge of the roof so you get complete water drainage.
You can use chemical de-icers on the edge of the roof. Clear the snow. At about every three feet along the edge of the roof, break the ice crust just above the ice block on the edge of the roof. Put de-icer in each hole above the ice dam and in a vertical line down to the edge of the roof. Use noncorrosive de-icers (see De-icers) and use as little de-icer as possible. Repeat as necessary rather than overdoing it the first time.
Removal
Removing ice mechanically from a sloped roof is always dangerous — both for the person doing it and for the roof. Removing ice will probably invalidate your shingle warranty. If ice must be removed, have it done by a professional with proper equipment and training.
Researchers learned a great deal about removing ice from sloped roofs by mechanical means in the winter of 1998. The most important lesson: always start at the top and work down. Starting on the bottom can release ice above you that can slide down and hit you. Small bumps of ice that remain on shingles are caught by ice blocks sliding down. As they slide, they catch and rip off the shingles.
Working from the top down allows you to use the ice on the roof as a slide for the ice that is being freed. Use a sledge hammer rather than an ax.The flexibility of the roof deck will cause the ice to fracture and you will not cut into the shingles.
Freezing Rain
Freezing rain is caused when there is a particular atmospheric “sandwich” of cold and warm air. Precipitation, usually snow, is formed in cold air high up in the atmosphere. As it falls, it travels through a layer of warm air that thaws it into light rain. Just before it hits ground level, it moves into another layer of cold air that brings its temperature to below freezing, but it doesn’t have time or the conditions necessary to crystallize yet. When it hits an object, it immediately freezes.
Snow will collect and then fall off wires and tree branches, and remain relatively light as it accumulates on roofs. Freezing rain compacts into tenacious ice that can weigh almost as much as water. The ice storm of 1998 was in fact a continuous series of small storms, one right after the other, that deposited up to 15 cm (6 in.) of ice on tree twigs, telephone wires, electrical lines and roofs. There is no way to stop freezing rain and it is not generally considered a hazard unless it becomes unusually thick.
The 1998 ice storm created two problems: direct weight and blockage of the natural flow of rain and melting ice. The freezing rain stuck all over the roof, not just on the bottom edge, and created ice dams. The dams backed up run-off water just about anywhere on the roof. Flat roofs suffered serious weight problems, while sloped roofs tended to suffer more water-penetration damage.
Common Winter Ice Dams
Under normal winter conditions, many houses in Canada form ice on the edge of sloped roofs or over part of flat roofs.
This is very different from freezing rain. It is caused by heat from the attic melting the bottom of the snow on the roof. When outside temperatures are just below freezing (0 to – 10°C), water flows down the roof under the snow and freezes when it reaches an unheated portion of the roof. This can create an ice dam on the lower edge of a pitched roof. Water can then back up under the shingles and into the roof space.
The first line of defence against ice dams is to reduce the attic temperature by stopping air leaks from the house below and adding sufficient insulation to the attic floor. Heating cables and other de-icing techniques are a last resort to minimize ice build-up and prevent water damage. For full details on dealing with common ice dams, see the CMHC’s Attic Venting, Attic Moisture, and Ice Dams.
Signs of stress
Water leaks showing up inside the house are troublesome and expensive to repair, but don’t necessarily mean that there is a structural problem requiring total clearing of the roof. Opening drainage paths may stop or minimize the leaks and avoid the expense and danger of clearing the roof. Structural stress shows up first at internal doors. They begin to jam.
New cracks show up in drywall and plaster. Jammed doors and cracks in drywall and plaster are usually near the centre of the house, not on outside walls.Watch carefully for these signs of stress. If there is significant change as an ice storm continues, take action. If signs of stress appear but do not change from day to day, the structure is holding solid.
On sloped roofs, another indicator is excessive sagging of the ridge line. If in doubt, arrange for an inspection by a professional, although during a crisis, that is easier said than done.
Recommended Procedures — Flat roofs with central drains
When is it a problem?
In most areas, flat roofs are built to safely hold a maximum of 17 to 20 cm (7 to 8 in.) of solid ice, or 38 to 43 cm (15 to 17 in.) of hardened snow, or 70 to 80 cm (about 30 in.) of fresh snow.
If there is more than 15 cm (6 in. ) of hard ice on your roof, you will have to lighten the load. Freezing rain accumulation can often resemble a hard snow more than a solid block of ice. Testing and judgment is useful. Pour hot water from a thermos in one spot. If it melts a small bowl and holds water, it is probably hard ice. If it cuts through to the roof, the accumulation is more likely hardened snow.
There may have been significant renovations below the roof to many older dwellings with flat or basin roofs. If walls have been removed or modified without full structural compensation, the roof may not even support 15 cm (6 in.) of ice. If signs of stress (see above) are significant, reduce the weight on the roof no matter how much ice is on the roof. You may also have to build temporary bracing inside the house.
Under certain freeze-thaw-freeze conditions, ice can exert strong lateral pressure on the parapet and other roof flashings.The pressure can cause roof leaks. It is a good idea to use one of the drainage techniques described below to separate the ice field from all flashings, leaving room for expansion of the ice field.
Drainage
Electrical Cables
If electrical power and wires are available, this is the easiest and most effective method of creating and maintaining drainage paths on flat roofs.
Shovel off loose snow. Clear about 60 cm (2 ft.) all around the drain. The safest way to do this is to use non-corrosive de-icers or hot water — a hammer or shovel may cause the drain to leak.
Lay electrical de-icing cables from near the drain to each corner of the roof. (Do not put the electrical cables inside the drain — the drain pipe may contain inflammable gases). Run a loop around obstructions, such as skylights and ventilation hoods. If you can work safely near the edge of the roof, run a cable around the inside perimeter (Figure 2).
Figure 2 : ‘X’ Formation on Flat Roof
The cable will melt its way to the roof surface and keep drainage paths open. It will not penetrate the ice until it is warmer than -10°C and, of course, will not work if there is no electricity.
De-icers for cutting into ice
Pour a 6-mm thick by 75-mm wide (1/4 in.-deep by 3-in. wide) path of de-icer from the drain to each corner of the roof and circle obstacles such as ventilators and skylights. Use the same drainage pattern as you would for electrical cables. See Chemical De-icers for details on products. You may need to use a de-icer more than once to melt through to the roof and to keep drainage paths open.
Ice removal is not a good do-it-yourself project. But homeowners can shovel heavy snow off the top of the ice, which might keep the weight load under control.
Ice thickness and weight of ice can be reduced with de-icers such as urea or even wood ashes. Both are slow and work only in relatively mild weather. To ensure water run-off, create drainage paths as described above. Ashes must be directly on the ice, with no snow over or under the ashes, so they can trap the sun’s heat.
Chemical De-icers
Many de-icers don’t show their ingredients on the packaging. Others list ingredients without showing the relative importance of each.This is no help in deciding which de-icer is safe for a roof or better at cutting drainage paths or reducing ice weight.
In general, the least expensive, most effective de-icers are highly corrosive and should not be used on a roof. Urea, the least corrosive, is also the least effective. In between are several products that are a bit more expensive, still effective and reasonably low in corrosive action.
In general, larger rock-like products tend to cut through ice quickly. Finer, powder-like products tend to perforate the ice. This creates a honeycomb effect that makes the ice lighter. Liquid products are the most effective for detaching blocks of ice from the surface.
Avoid
Salts containing oxidizing agents (these accelerate corrosion and rust and can deteriorate other roofing materials) such as:
NaCl (Sodium Chloride)
CaCl2 (Calcium Chloride)
Safer materials
CMA (calcium magnesium acetate)
The following are normally used as fertilizers:
Urea
KCl (Potassium chloride)
(NH4)2 SO4 (Ammonium Sulfate)
Life Safety
Ice is slippery and in emergency conditions medical help may not even be able to get to you. Not only can you slip, but ladders can slip. Removing ice from the edge of a sloped roof can release large fields of ice higher up that can slide down on top of you. During the 1998 ice storm, more than one person died from icicles falling from above when they were simply standing in the driveway below.
Double and triple your safety precautions, or stay away from the roof. Rope off areas and access doors where overhead ice is heavy or slides made occur (Figure 3). Never work alone. Always have someone on the ground to ensure that what you throw off the roof is landing safely.
Figure 3 : Rope off areas where overhead ice is heavy or slides may occcur.On a sloped roof, always tie the ladder down and have a safety rope over the top of the roof secured on the other side.The safety rope should be attached to a full safety harness, like mountain climbers use — it is not there just in case you slip — it is there because you will slip and more than once.
Special ice cleats are available in shoe repair and hardware stores for attaching to shoes and boots, making them much like golf shoes. These are good for not slipping, but are not good for shingles. Walking on icecovered sloped roofs is best left to professionals with professional equipment.
Detaching ice blocks from surface
Liquid de-icers (e.g. Clear Away) were efficient at melting the bond between blocks of ice and roof membranes.
Methyl alcohol worked as well.
Techniques with moderate success
Cutting drainage paths with hot water
This is actually rather effective if you can get hot water very close to the ice (50 to 100 cm — about 2 ft.) and prevent the hose and nozzle from freezing (Figure 4).
Figure 4 : Hot water being sprayed from dormer window.The drain must first be freed of ice, so that the water can drain away. However, this means you will be undercutting the mass of ice above you, and this ice may come down.
The only safe way to do this job is to cut thin slices off the ice — about 30 cm (1 ft.) — all the way from the gutter up the roof. Keep your ladder off to the side, so it won’t be hit by ice coming off the roof.
Hot water jets from regular garden hoses proved very effective on metal sheds and glass sunrooms when directed from dormer windows above. Do not walk on metal or glass roofs. Cut the ice into sections with the jet, then flood the glass to unhook and slide the ice off. Windows below may need protection from rebounding ice.
Steam
In the research conducted in 1998, no suitable contractors were found to be using steam.
Subsequently, CMHC has heard from contractors who have had success with this method. If you can find an experienced contractor, this method may work for you.
Experiments that did not work
Solar Collectors
Both clear and black polyethylene and solar swimming pool covers were tested for melting ice.Wind problems (how do you keep the cover in place?), lack of evaporation, as well as snow cover rendered them all just about useless.
Liquid De-icers
Although they did work to liberate the ice blocks cut by chain saws off flat roofs, they were not effective in cutting drainage paths on the edge of sloped roofs.
by admin | Jan 4, 2012 | Blog, Energy Saving, Home Improvement
Replacing Your Furnace
There are usually two major reasons why you are choosing another forced-air furnace. The first is that your furnace does not function. It has just broken down, irrevocably, or it has been “red-tagged” or condemned by gas inspectors. If it is winter, and your house is getting colder quickly, you may not have the luxury of making a reasoned choice on what to buy next. The other situation is that your furnace is getting old, or your fuel bills are becoming too excessive to tolerate. In this case, you have the time to shop around and get the best furnace and fuel for your situation.
This About Your House is written to address both situations. If you have a dead furnace and a chilly house, you will probably take some shortcuts in your selection process.
Choice of Fuels
For many years, CMHC and others could offer sound advice on what fuel choice would be the most economical. During that period, heating systems based on electricity or propane cost the most to operate. Heating oil was somewhat more economical, and natural gas (if available in your community) was the least expensive choice.
Since 2000, the prices of these commodities have been fluctuating, and it is difficult to offer reliable advice on pricing. At one point in 2001 – 2002, heating with electricity in Manitoba was as economical as heating with natural gas. Predicting these prices over the next two decades (a common life span for a furnace) is nearly impossible. The best advice is to make a calculation based on the current prices quoted to you in your locality. See the text box entitled “Calculating fuel costs.”
Calculating Fuel Costs
Here is a rough comparison of the relative costs of heating an older house in Ottawa. You can put in your own fuel prices and the efficiencies of the appliance that you are choosing to compare relative costs.
Note: It is often difficult to isolate the cost per unit of fuel, be it gas or electricity. Include all the costs that relate to the m³ of consumption forgas (for example, gas supply charge, gas delivery charges, gas surcharges). Electric utilities often also have a bewildering range of charges. Apply all the charges except fixed charges (for example, $10/month connection charge).
For oil appliances, use an energy content of 38.2 MJ/litre of oil. For electricity, use 3.6 MJ/kWh and 100-per-cent efficiency.
Note: 80 GJ (or 80 gigajoules) is the energy required for heating the example house over the winter (heat load). Your own house will likely be different. However, the relative costs calculated for alternative fuels and furnaces in the example house should help you make a selection for your house.
Furnace Sizing
You probably do not need a furnace with the output of your current furnace. Most furnaces in Canadian houses can provide far more heat than the house requires. A properly sized furnace will be running almost continuously during the coldest day of the winter. Having a furnace of a correct size will result in efficient operation during the whole heating season. A grossly oversized furnace will run only for a short period, never coming up to peak efficiency. Note, however, that sizing may not be a big issue with high-efficiency, condensing gas furnaces. Due to the design of condensing appliances, they are efficient even when oversized.
So, how do you size your furnace? You can have the contractor use a home heat loss calculation that is available from Canadian Standards Association (CAN/CSA F280) or a sizing procedure from the Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI). Having a proper sizing will cost you $150 – $300 from a qualified contractor.
Those who keep their heating bills, and who are mathematically inclined, can try the calculation in the text box entitled “Calculating house heat loss from utility bills.”
Calculating House Heat Loss from Utility Bills
Here is a sample calculation, using a three-month meter reading for a typical house. You can use any period (but at least two weeks of winter weather is necessary). You can read the meter yourself for the information, look at your furnace bills or phone your utility to see if they have appropriate records. The natural gas usage of other gas-fired appliances in the house is estimated from gas utility data and subtracted from the total for the period in question, so that the gas requirement for heating can be isolated. (Oil furnaces are harder to size using this method, but it may be possible using oil fill-up intervals and the number of litres delivered.)
The goal is to find a relationship between the gas consumed and the heating degree days (HDD). A heating degree day is essentially the number of degrees of heating required over the course of 24 hours, compared to a reference temperature of 18°C. For example, if the average daily outside temperature is 10°C, then the number of heating degree days for that day is 18°C – 10°C = 8 HDD. You can get the approximate HDD for your calculation period from the Environment Canada website. Use the data from the “Degree Days: Below 18°C” row.
Once the relationship of the HDD and gas consumption is established, then you can calculate gas consumption for the design temperature in your area. This temperature is usually available from a mechanical contractor or your local building officials. It is not the extreme minimum temperature; it can be estimated from the average temperature over 24 hours on the coldest day of the winter. To approximate the design temperature: go to the historical weather data for your community on the Environment Canada website; find the coldest January over the last several years; then pick out the lowest daily average temperature in that month; and use that as the design temperature. Being a degree or two out will not make a huge difference in the calculation.
The example below uses a design temperature of -35°C. At that temperature, the maximum HDD per day is equal to 53, which is the difference between 18°C and -35°C. Calculating the size of the furnace necessary on the coldest day of the year will mean that the furnace has the capacity to handle any expected local temperature. You can find a furnace’s efficiency rating on its EnerGuide label or in the product documentation.
Example
Total gas consumption from December to March = 1,320 m3
Estimated consumption for other gas appliances (data from utility) = 306 m3
Therefore, gas consumption during the period for heating = 1,320 – 306 = 1,014 m3
Heating degree days for that period (from Environment Canada data) = 2,840 HDD
Heating consumption by degree day = 1,014 m3/ 2,840 HDD = 0.3570 m3/HDD
Heating consumption at 53 HDD/day = (53 HDD/day)(0.3570 m3/HDD) = 18.9 m3/day
Where gas has an energy content of 37.5 MJ/m3, and the existing furnace has an efficiency of 72 per cent, then:
Heat loss at 53 HDD/day = (18.9 m3/day) (37.5 MJ/m3)(0.72) = 510 MJ/day or 21.3 MJ/h*
According to the energy content of electricity, 3.6 MJ/h = 1 kW, then 21.3 MJ/h = 5.9 kW
This heat loss would require a furnace that produces an output of 5.9 kW or about 20,100 Btu/h (1 kW is approximately 3,412 Btu/h).
If we allow the CAN/CSA F280 permissible oversizing of 40 per cent, then the proper furnace sizing would be (1.4)(20,100 Btu/h) = approximately 28,100 Btu/h.
If you are calculating for an oil furnace, heating oil has an energy content of 38.2 MJ/litre.
* Note: This calculation is correct, although many people think the efficiency factor is in the wrong place. It is not. We are calculating the house heat loss based on fuel used and furnace efficiency. A more efficient furnace will have delivered more heat to the house, and the heat loss will be higher.
Furnace Efficiency
There is a wide range of furnace efficiencies, although only high-efficiency gas furnaces are sold in Canada as of 2010. The range of efficiency will vary by fuel.
Electric furnaces work on electric resistance. The full 100 per cent of the energy consumed goes towards the heating of the house. The inefficiencies with electric heating happen before the electricity reaches your house. If the electricity is created by burning fuels, there are inefficiencies in that process plus losses as the electricity moves through the lines.
Oil furnaces have become far more efficient since the height of their popularity in the mid-twentieth century. Efficiencies have risen from roughly 60 per cent to well over 80 per cent as a result of advanced technologies — first to flame retention head burners and then to high static pressure burners. The more efficient oil furnaces require a better chimney than their conventional counterparts, so you will probably need to upgrade the chimney with a stainless steel liner inside the old clay tile. Make sure this is included in the quote.
Failure to have a properly sized chimney will result in excessive chimney condensation and eventual destruction in the case of masonry chimneys. There are high-efficiency, condensing oil furnaces as well. Earlier versions had reliability problems. The new generation, launched in 2003, may have resolved these difficulties.
New gas furnaces in Canada are high-efficiency (89 – 96 per cent) condensing furnaces. The high-efficiency furnaces use a plastic vent and are most often vented out the side wall. Propane furnaces are usually modified natural gas equipment.
So… What Do I Buy?
Here are the most common questions about furnace replacements to CMHC staff from Canadians, and our usual answers:
Should I switch my heating fuel?
In most parts of Canada, it will be more expensive to heat with an electric furnace than one using oil or gas. An exception would be if you heat primarily with a wood stove and use the furnace only infrequently as backup. In this case, the low cost and low maintenance requirements of an electric furnace may be a major advantage. Deciding between oil and gas furnaces is a matter of choice. Make the calculation to see if it is significantly cheaper to use one fuel or another based on current prices in your area. Oil furnaces require a tank and usually a chimney. There may be additional costs for chimney modification or oil storage tanks when purchasing an oil furnace. Some home insurance companies require periodic oil tank replacements. Check if a new gas furnace would also require relining the chimney. Consult with your contractor and make sure that these costs are included in your estimates.
Some dealers recommend a furnace of 100,000 Btu/h, and some say 80,000 Btu/h will be fine. How do I choose?
See the previous discussion on sizing. If you are buying an oil furnace, proper sizing will affect the durability and efficient operation of your appliance. Your choices are either to pay for a proper heat loss analysis, to calculate house heat loss or to accept the dealer’s estimate. Sometimes government or utility programs subsidize house testing. If such a program is in effect in your vicinity, this can be an economical way to have your house heating load established.
Are there any advantages to multi-stage, multi-speed furnaces?
Multi-stage furnaces have become more popular lately, although they are more expensive than the single stage furnaces that have been sold for decades. Multi-stage furnaces have two or three levels of burner function, and an efficient, modulating circulation fan to move the heat into the house. They can provide additional heat when a quick temperature rise is required, such as in the morning when a house with a setback thermostat is being heated from 15°C to 21°C (59°F to 70°F). A traditional single speed furnace would take longer to get up to temperature. The multi-stage furnaces are no more efficient than single-stage furnaces; they offer more flexibility and perhaps more comfort.
Is Furnace “A” better than Furnace “B”? How can I find that out?
There is little or no available data to show that one manufacturer’s furnace will operate longer and with less trouble than a furnace from another manufacturer. This is frustrating for consumers. We are used to being able to read ratings of one product versus another product and to make a choice based on those ratings. However, a good furnace will last 25 years. A poor one may break down prematurely at 15 years. With lifetimes of this length, and with furnace design and model changes, it is hard to predict which furnace will provide the best service.
There are two factors to help you in your choice. Pick a furnace with a long heat exchanger warranty, 20 years or more. If manufacturers are willing to back the most expensive part of their appliance for a long time, this should inspire some confidence. Also, pick a furnace manufacturer and a dealer that have been in business for a significant period of time. A furnace with a lifetime warranty offered by a company that has been in operation for only three years may not be the best deal. One would expect to pay less for this level of uncertainty. Look for contractors with memberships in trade organizations such as HRAI, which would indicate an interest in professional qualifications.
The Hot Water Heater Conundrum
There are very few high-efficiency hot water heaters available. Changing your furnace may lead to having to think about your hot water heater. Existing hot water heaters are often located vertically below the kitchen and bathrooms, where the water is used. If you are changing from an electric to a conventional gas hot water tank, and the new gas appliance has to be installed across the basement to be near the chimney, you will be waiting longer for the hot water at the tap. Consider a gas hot water tank that has side-wall venting and does not require a chimney. This way, it can stay close to the plumbing appliances that use it.
Another hot water tank issue can occur when you switch from a conventional gas furnace and hot water tank to a new, high-efficiency side-wall vented furnace. Now the hot water tank has to heat up that big chimney all by itself, and you probably will have to pay for chimney relining. It is often better, when choosing a chimneyless furnace, to switch your hot water tank to side-wall venting at the same time and seal the old chimney closed. However, side-wall vented hot water heaters are more expensive than conventional hot water heaters and can be noisier.
Instantaneous hot water heaters, which do not use a storage tank, are becoming more common. They may be more economical to operate.
Furnace Circulating Fan Choices
Most furnace circulating fans consume high amounts of electricity (300 – 700 watts). If you will be using your furnace circulating fan to move ventilation air around the house (for instance, if you have a heat recovery ventilator connected to it, or a high-efficiency air cleaner on the furnace), then look at upgrading the circulating fan to a high-efficiency DC motor. The best furnace fans now will use less than 100 W on low speed. This will result in considerable electrical savings over the life of the furnace.
Other Choices
When replacing the furnace, you may want to look at integrated systems that heat your house and your water and also provide ventilation. Devices known as “combo” units provide house and water heating. New appliances with advanced, integrated systems will provide ventilation as well as space and water heating. For some replacements, these integrated appliances will be your best choice.
Additional Resources
For further detailed information on all heating appliances, there are excellent booklets published by Natural Resources Canada in the Heating and Cooling Series.
by admin | Jan 4, 2012 | Blog, Home Improvement, Home Maintenance, Home Repair, Interior design
Painting: Walls, Ceilings and Floors
Compliments of www.cameronpaine.com
Painting is not the chore it used to be. A professional look is now easier to achieve. Whatever your project, talk to the paint experts where you purchase your paint. They are a valuable resource.
If you are having a hard time visualizing the colour, inexpensive computer software programs can allow you to try out different colours. Or, there may be a decorating service where you buy your paint.
Selecting paints
There are two main types of paint depending on the thinners and binders used; water-based (or latex) and oil-based (or alkyd).
Water-based paints use water as a thinner. They are often called latex paints even though they don’t use real latex, since rubber is not used as a binder any more. Today synthetic latexes are used, most commonly acrylic or polyvinyl acetate. Paints with a high acrylic content tend to have a tougher skin and can perform almost as well as oil-based paints. Latex paints can be easily cleaned up with soap and water.
Oil-based paints use a solvent thinner. Despite the name, oil-based paints are usually not made with oil. Instead, most use polyester resins, called alkyds. Although alkyds may be more durable and achieve a higher gloss finish, they are usually a less healthy choice than latex. Alkyd paints require mineral spirits for cleaning up.
Because paints are applied wet, and because they cover such a large area, paints can create a significant health problem during a renovation project. The problem is mainly caused by alkyd or solvent-based paints. They give off a number of volatile organic compounds (VOCs) as the solvent evaporates after painting.
These VOCs can be a strong irritant and can add to air pollution. Once the paint has completely dried and formed a tough skin, the emission levels drop. However, some paints can emit odours at low levels for a long time.
Exposure to VOCs varies from person to person. Effects include coughing, headaches, dizziness, or more serious conditions. It is especially important for respiratory sufferers, those with allergies, asthma, and households with young children or pregnant women to avoid paints with VOCs.
Comparing the VOCs of one paint to another is not an easy task. Material Safety Data Sheets (MSDS) are helpful, but manufacturers don’t have to list components which make up one per cent or less of their product’s weight. This means that some toxic components may not show up on the MSDS. The only sure way to know what the paint contains is by asking the manufacturer to list trace compounds.
There are some paints on the market that are solvent and VOC free. Look for the key words: Low VOC, or better yet. No VOC.
Painting myth
Contrary to popular belief, you can paint over oil or alkyd paint with latex paint.
To do so the walls should be cleaned, painted with a super adherent acrylic primer, then latex paint can be applied.To test if the paint on the walls is oil or alkyd some stores carry inexpensive test kits, or you can use methyl hydrate (gas line anti-freeze) or non acetone based nail polish remover.
Apply a small quantity of one of these products to a pad and rub vigorously on the painted surface. If the surface remains shiny it is oil/alkyd; if the paint is stripped it is latex.
Types of paint
It can be confusing when selecting the sheen of paint you want since the term used for the sheen varies by manufacturer.
Low-sheen (low-gloss) paints have none to little observable sheen. The amount varies slightly by manufacturer. Low-sheen paints can be called: flat, matt, eggshell, satin and velvet.
Higher sheen paints are semi-gloss, gloss and enamel. They have the most visible shine to them.
Low-sheen paints can be washed, but with care, higher sheen paints are the most washable and have the most durable finishes.
Most people select semi-gloss or high-gloss paints for rooms with high moisture levels such as kitchens and bathrooms, and high traffic areas such as main stairways and halls. Most people prefer to use semi-gloss or high-gloss paint on windows, trim and doors.
Bedrooms, dining and living rooms are more commonly painted with lower sheen paints.
Years ago, enamel meant oil-based paints.Today the term enamel can also mean durable latex paint.
Sealers are primarily used on new wood or masonry surfaces. They seal the surface of the material, forming a base coat which keeps the topcoat from being absorbed unevenly. They can be used to encapsulate materials to seal in gases thus preventing them from offgassing.
Primers are used to make the substrate more uniform, and to create a tight bond between the topcoat and the surface to be painted.
Cementious or masonry paints are used on concrete walls and floors.
Ceiling paints are designed not to drip.
Melamine paints are used for cabinets and shelves, and are very durable and washable.
Choosing paint by the brand is not enough. Many brand manufacturers make higher and lower quality lines of paint. As you move up in quality so does the price. Each grade is usually a few dollars more expensive than the previous grade. Avoid mixing the brands by using the primer of one brand with the finish paint of another. Paint will adhere better if you use the same brand for both applications.
If you buy all the paint you need at one time you have a better chance of getting a uniform colour.
Brushes and other tools
Ensure the rollers and paint brushes you buy are rated for the type of paint you are using. Better quality brushes help ensure that the paint strokes are less visible.
Estimating how much paint you will need
Measure the height and width of each wall to be painted then multiply to obtain the square footage.
For rooms with lots of windows and doors deduct the square footage of the windows and doors.
A 4-litre (1 gallon) pail of paint will usually cover 37 square metres (400 square feet).
When calculating how much paint to buy, check how well it is expected to cover the surface to be painted. This is called hiding quality. Painting over very dark colours may require using primer as the first coat or more coats of paint.
Having the primer tinted the same colour as the finish coat can provide better hiding qualities.
Latex based paints should not be stored for extended periods of time as they can go bad. When buying paint look for the most current date of manufacture on the container.
Getting ready
Preparation is the most important and most time consuming part of painting. Usually at least 80 per cent of the time spent on a painting project is spent getting ready and cleaning up.
- Assess the surface that requires painting for needed repairs. Popped nails in the drywall or wallboard can be corrected by screwing a new screw into the stud either two inches above or below the popped nail. The popped nail can then be nailed in and the holes filled with wallboard or spackling compound. Make the patch on the hole as smooth as possible to minimize sanding.Wear a mask while sanding using no. 100 or no. 120 grit sandpaper if using wall repair compound and no. 220 grit for spackling compound.
- For larger holes the compound may need to be applied in layers. Each layer should dry before the next one is applied. To help the compound bond to the drywall, apply a layer of glass fibre (mesh) tape. It comes in a roll similar to cellophane tape.
- Vacuum the whole room and damp mop the floor if possible. Wash the surface to be painted with mild detergent and water. If there are grease marks on the walls, or if someone in the household smokes, you may first need to clean with TSP (tri-sodium phosphate). If using TSP, be aware that it is not a benign product, and should only be used while wearing rubber gloves and eye protection. Rinse well with clean water.
- For very textured walls or ceilings, vacuuming may be the only pre-cleaning option.
Painting new drywall or wood
Previously unpainted drywall, or plaster must be primed. Previously unpainted wood can be stained, painted or urethaned.
Special considerations
Lead in paint
Lead in interior paint was taken off the market in 1979. Paint in houses or apartments built before that date almost certainly contain small amounts of lead paint.
Exposure to large amounts of lead can cause serious illness. Infants and children are especially vulnerable to lead. However, lead paint is not generally a problem if it is not flaking, peeling or blistering.To check if the walls contain lead, you can obtain a lead paint test kit at most major hardware and some health food stores.
Sanding or heat stripping lead paint requires safety precautions, including protective clothing, a mask, goggles and gloves. Lead paint in the form of sanded particles are a health hazard.
Pregnant women and children should never be exposed to dust or fumes caused during lead paint removal.
For further information on lead, order the free booklet Lead In Your Home from CMHC.
Covering water stains, marks and knot holes
Water stains on ceilings, wax crayon marks on walls and previously unpainted knot holes will bleed through most water based paints. A special stain blocking sealer should first be applied sparingly on the knots, stains or marks before applying the paint. For these special situations you may need to use shellac, alkyd or a polyvinyl acetate primer.
These products have an odour and therefore should be used only on the affected areas. When using these products ventilate well, preferably by running a fan. Place the fan in an open window and have the fan facing out.
Severely damaged walls
If walls are badly damaged, it may be quicker and cheaper to install an additional layer of new drywall.
Peeling paint
Peeling is usually a result of moisture under the paint, or of using the wrong type of paint. If moisture is the cause, it must first be corrected, then the surface can be scraped and sanded before painting.
Covering mold and water stains
Mold which appears as dark spots on the painted surface must be washed with soap and water, rinsed and dried before repainting. The cause of the moisture which resulted in mold, if not corrected, will allow the mold to come back.
Painting tips
- Do not excessively thin paints as this decreases their wear resistance and washability.
- If you use solvents of any kind, store the used solvents in an old paint container with a seal and take them to the toxic waste centre in your community. Do not pour solvents down the drain.
- Always paint with a window open and when the temperature is above 10°C (50°F).
- You can remove solvent based paint from your skin by using vegetable oil.
- Smooth evenly painted walls are more readily achievable if you:
- Sand really well after patching.
- Use a roller which you have taken a lint brush to, before using.
- Use a roller designated for the type of paint you are using.
- Clean the surface to be painted thoroughly after sanding.
