Turning on the Heat
Thoroughly inspect all water systems before you turn on the heat. Include the water systems in the basement, to find out if there have been leaks or pipes that have frozen and burst. Inspect all visible piping, the hot water tank, traps under kitchen sinks and bathroom vanities, etc. Once you are satisfied that everything is normal, then turn on the heating system. Be sure to follow your electrical utility's instructions about power consumption. If you're heating by electric baseboards, try heating-up the kitchen, living and dining room and washrooms first. Then heat the basement, and then the bedrooms afterwards, to alleviate loads on the network. If you have a hot-water furnace, it is best to call a heating contractor. You will have to heat up the house by other means, before having the system recharged with water. If you have a gas or oil-fired hot air heating system, make sure the gas valve or oil valve is turned on. Be alert for natural gas or other telltale odours.
Water issues
Do not turn on the water in the house until the indoor air is returned to near normal temperature (e.g., 20°C) Close all open faucets, close the hot water tank drain, and reconnect washing machine hoses.
Turn on water at the water service entrance. Ensure that hot water taps are running and that the hot water tank is full before turning on the hot water tank. Electric hot water tanks can be turned on at the breaker. If you are unfamiliar with the operation of your gas hot water tank, call in a service person to restore gas to the tank. Turn on the highest tap in the house until water is flowing to bleed air out of the system. Ensure that drains are not clogged with ice or cracked by freezing.
Run other taps until water is flowing. Check for leakage of pipes where possible. Check the condition of taps or faucets which have been threaded for connection to a hose. Leaks can often be heard before they are seen. It is a good idea to have people observing and listening in all areas of the house where water lines are present to detect leaks early. If leaks are found, turn off water supply to that line or turn off water at service entrance until leaks are repaired.
Operate appliances one by one to detect leaks in the drainage system - flush toilets, run water in each sink, lavatory, shower and bathtub. If your house or building has a flat roof, try and check the rain water leader leading from the roof drain to see if it is operating. If it is not blocked or frozen, it should be cold to the touch and slightly damp, indicating that cold water or cold air is circulating in the pipe. If it is warm or you know it is blocked , you should have the roof drain checked by a qualified contractor and cleared if blocked. Check sump and sump pipes for freezing before re-starting the sump pump.
Electricity/Power Issues
Do not activate major appliances until they have returned to near normal temperature. Ensure that stoves, ovens, washing machines, dryers, microwaves, VCRs, stereo systems and portable space heaters are turned off at the switch. Turn on power to the house at the breaker box. Turn power on to individual appliances (including refrigerators and freezers) when they are warmed up.Roofing Issues
General -- It is best to have experienced contractors work on icy roofs as they have the training and equipment needed to avoid accidents. For newer houses in the greater Montreal area, roofs are designed for an allowable load of around 40 pounds per square foot (40lb/sq.ft.). This equates to approximately 8 inches of pure ice. Ice weighs about 5 pounds per inch thickness. It generally takes 10 inches of dry snow to equal 1 inch of ice. Wet snow, and ice pellets will weigh more than snow but less than ice. For older units or buildings, it is safer to assume that the maximum allowable load will be lower than for newer buildings. This could be as low as 30 pounds per square foot (30lb/sq.ft.)
You need to have the thickness of ice and snow determined by an expert roofer or contractor. If loads exceed the design load, then excess load must be removed. Removal of ice and snow should be left to the experts who may use a variety of methods and special tools, including manual removal, the use of non-corrosive de-icers, heat from blow torches, electric heating cables and hot water or steam. Extreme caution and care must be exercised to ensure safe manoeuvres and prevent damage to the roofing membrane or shingles.
Cracks in interior finishes at the ceiling of flat and cathedral roofs may indicate excess loads. Other indications of excess load are doors that no longer fit in their frames and new cracks over openings in walls, both interior and exterior. In extreme cases of overloaded roofs, it may be necessary to have a contractor build a temporary bearing partition at mid-span to alleviate some of the load.
Flat Roofs -- Flat roofs are generally provided with a roof drain at the lowest point of the roof. To prevent further accumulation of ice, it is imperative that roof drains be cleared of ice and operating. To prevent damage to the underlying membrane, ice around the perimeter of plumbing stacks, and goosenecks for roof ventilation and exhaust fans (kitchen and washrooms) should be cleared. Calcium chloride de-icing salts should be avoided, as they are corrosive and may damage steel flashings, goosenecks and metal rain water leaders. Urea based de-icers are non-corrosive and are environmentally safe.
Sloped or Pitched Roofs -- Sloped roofs, those with non-existent eave protection, may leak at the eaves because ice dams cause melted snow or ice to back up under the shingles. (eave protection is a 3 foot or one meter wide strip of continuous waterproof material applied to the roof deck along the eaves, before applying the shingles). Any water backing up under the shingles drains down the roof on this material instead of leaking into the house.
Heavy ice/snow may have caused similar conditions at any location on the roof. If you have a roof leak higher-up on the roof, it is most likely due to a leaking flashing protecting equipment piercing the roof line.
An inspection by a qualified roofer, contractor or building inspector, will help determine the cause of the leak. Ice build-up at the eaves and eavestroughs caused by an ice storm, may cause ice damming and water leaks where none has occurred before. It is better at first to remove the ice from the downspouts and eavestroughs using Urea based de-icers. Another possibility is to have special heating cables installed by a qualified electrician as a permanent solution .