While previous generations may have been content to live in drafty houses, most people now want comfortable warm houses. A healthy house today is well sealed, well insulated and properly ventilated.
A well-insulated house is a bit like dressing for the weather. A wool sweater will keep you warm if the wind is not blowing and it is not raining. On a windy, rainy day, wearing a nylon shell over your wool sweater helps keep you reasonably dry and warm. A house is similar. On the outside, underneath the brick or siding, there is an air barrier that does the same thing as the nylon — it keeps the wind from blowing through. Then there is the insulation (like your sweater) and a vapour barrier, which helps keep moisture away from the house structure where it can do damage.
Signs of Insulation Problems
In the winter
- walls cold to touch
- cold floors
- high heating costs
- uneven heating levels within building
- mold growing on walls
In the summer
- uncomfortably hot inside air
- high cooling costs
- ineffectiveness of air conditioning system
- mold growing in basement
R values and their metric equivalent, RSI values, are a way of labelling the effectiveness of insulating materials. The higher the R value or RSI value, the more resistance the material has to the movement of heat. Insulation products sold in Canada are labelled with R and RSI values. Provincial building codes specify minimum R (or RSI) values for new construction, with different values for different applications. It is important to know what your local building code requires when planning new construction.
Note: The way the insulation is installed plays a large role in its effectiveness. Compressing the insulation, leaving air spaces around the insulation and allowing air movement in the insulation all reduce the actual R value of the insulation.
Read more: http://www.cmhc.ca/en/co/grho/grho_010.cfm