Roofing material is expensive, and if you only plan on having this job done once, then you will want it done right.  A quality installation is required to avoid running into these problems again.  Be prepared to fork over a pretty penny to contractors to ensure that the job is done well and correctly.

Your roof is the one element of your home that is directly exposed to all the elements.  No other part of the home sees as wide a variety of seasonal elements as the roof.  It is a major home improvement, and chances are you would only have it done it you had to because of damage.  The trick is to prevent the damage by properly taking care of your roof and getting it ready for the onslaught of winter.

Source:  http://kingstonroofing.ca/why-roof-replacement-is-a-major-home-improvement-project

Maintain your heat source.  Whether you have a furnace or a wood burning stove, it is ideal to keep it in tiptop condition, because it could be the difference between life and death.  It is advisable to have back up heat sources on hand just in case.

Always keep a well-stocked pantry of non-perishable food items that can carry you through a bad snowstorm or blizzard.  In addition, keep first aid supplies, flashlights, batteries, candles and matches, blankets and warm clothing on hand in the event of an emergency.

The preparation for your home should take place in the fall months.  At this time, it is smart to invest the time and energy into your home.  For example, prepare the roof and gutters for the winter by clearing them out to prevent clogging and ice dams.  As well, ensure proper ventilation in the attic to prevent snow and ice from melting on the roof.

Source: http://www.associatedcontent.com/article/494671/winter_storm_preparation_pg2.html?cat=6

Equally enough, mold is unable to grow on dry materials so making sure that your home is properly insulated and sealed off from moisture build up will help greatly in preventing this for occurring.

If you think your home might be suffering from moisture issues and are starting to see mold forming, this is something you should take care of immediately.  Mold will start to compromise the structural integrity of your home as well as your health.  This is very serious and should not be taken lightly.

With over 280 different types of mold, the odds of your home suffering from an infestation are pretty good.  Luckily, with the help of specialists and professionals this is an issue that can be eliminated.

Snow loads are a major problem for many homes in the winter. Different homes have various live loads (temporary load that a roof structure is designed to support). Many homeowners find themselves with snow loads their roofs are unable to handle which leads to leaking and other permanent damages. As you already know, snow is essentially frozen water. That being said, snow loads can vary due to several factors such as height and moisture content ranging from dry to wet.

The water content of snow varies; dry snow has approximately 4% water content, while wet snow has approximately 35% and Ice is about 95%. Currently the average roof is able to support about 20 lbs per square foot. It is important to remember that this varies due to poor construction and cheap building materials.

Homes come into real danger when the snow on a roof becomes very wet or turns into ice. Since a cubic foot of ice almost weighs a cubic foot of water you can imagine the strain that is put on a roof when there are a few inches of ice (since a square foot of 3 inches of waters weighs approximately 16 lbs). It is impossible to tell whether your house was built to withstand heavy snow loads unless you were highly educated in engineering and construction. Therefore the safest move is to have the snow removed in order to save your home from extensive damages.

Being up on a roof can be very dangerous never mind when it is covered in snow and ice. This is why it is very important to hire a professional who has experience in snow removal. Remember it will be very cost effective to solve the problem as soon as possible before really serious damage is done to your home.

Drift

Snow drift plays a major role in roof damage. This is because it displaces large amounts of snow on particular areas of a roof. Snowdrift is the process of wind moving snow and placing it in a different area. The drift generally stops at stationary objects such as walls or changes in the slope of a roof.  This process is quite common and can cause a great deal of stress on a roof.

It is important to have stack effect as it helps to balance the air flow through your home.

The stack effect will always bring air infiltration, since buildings are never completely sealed.  During the heating season, warmer indoor air rises up through the building and escapes at the top either through open windows, ventilation openings, or leakage. The rising warm air reduces the pressure in the base of the building, forcing cold air to infiltrate through either open doors, windows, or other openings and leakage. During the cooling season, the stack effect is reversed, but is typically weaker due to lower temperature differences.

High rise buildings, that have a well-sealed building envelope, must account for significant air pressure differences due to the height of the building.  There must be a well planned mechanical ventilation system.  Stairwells, shafts, elevators, and the like, tend to contribute to the stack effect, whereas interior partitions, floors, and fire separations can mitigate it.  In case of fire, the stack effect needs to be well controlled to prevent the spread of smoke and fire.