Weekly Home Information Guide
INSULATION
Adequate home insulation either newly applied or as a retro fit helps keep the warmth in, energy cost down and the cold outside where it belongs.
Insulation comes in a variety of forms for the various uses in the home. Loose fill (cellulose, vermiculite, perlite, zonolite) is used for the hard to get at places, rigid for foundation applications, and the most popular fiberglass batts type (used between the wall studs and floor/ceiling joists). Foamed in place insulation was a much-touted material but now has fallen out of favour. All insulating values are rated as to their resistance to heat loss or "R". This rating is designed to give a comparative value when judging the qualities of the various insulation types. For example, fiberglass batts has "R" 3.3 per inch, mineral wool has "R" 3.6 per inch, loose cellulose "R" 3.7 per inch and rigid sheet has "R" 4.4 per inch.
Our west coast region calls for at least 6 inches of wall insulation, 10 inches of attic/crawl insulation and 2 inches of interior/exterior/underground perimeter insulation. An experienced insulation contractor will help you decide the best application for your particular needs. Homeowners should take a survey of the total insulation values of their home and then decide if more is needed. Due to some construction practices it may be difficult to determine what type, the amount and condition of the insulation present.
Most of home heat loss is through the attic space (about 65%), through the walls (about 20%) and through the basement/crawl (about 15%). This would indicate the quickest and usually easiest upgrade would be to add insulation to the attic areas of the home. If the home is partially insulated you are already saving about 30% of your heating bill as compared to a similar sized home that is not insulated. If the home is fully insulated you are already saving about 75% of your heating bill as compared to a similar sized home that is not insulated.
A vapour barrier may or may not be present on the ceiling below when view from the attic. A good depth of 10 inches is recommended for attic spaces but be cautioned, some types of lighting require a dead air space. Have all wet insulation removed and the overhead problems corrected before any new insulation is added. The use of insulation/rafter baffles where needed is advised. These baffles help maintain the proper clearance for free air movement above the insulation and the underside of the roof deck. This is the quickest return of your investment dollar.
Retro fitting the wall cavity can prove to be a bit more complicated/costly. Again, we strongly urge you to consult with a reliable carpenter for all upgrades.
Crawl areas have the disadvantage of being in a cramped workspace, they are dark, smelly, cold, and of often poor construction practices. We often see the end result of poor maintenance, something of which is altogether avoidable, and result in cold floors and rotting wood framing. There are many upgrades that can be done to the crawl areas and some of the best ways is to add the proper type of insulation, above/below ground rigid board and a vapour barrier.
Typically, homes built after 1965 will have insulation in the wall, attic and basement/crawl areas, homes built before 1965 may have some insulation in the wall, attic or basement/crawl areas and homes built before 1950 may not have any insulation at all. With the various construction practices and age of the home the safest approach is to seek competent advice. Older trailers, depending on the year of manufacture and location of the manufacturer, may have minimum insulating values. About 1985 the insulation values were the same as for houses.
The advantages of batts insulation include noise reduction, lessened heat transfer, reduced energy costs, it will not rot, is dimensionally stable, is non-combustible, is non-corrosive and vermin proof. This material is easiest to apply by the homeowner. Use adequate clothing and breathing protection.
The advantages of cellulose loose fill include the above plus able to get into hard to reach places. A contractor usually blows this material into place. The homeowner can perform the same but is usually more time consuming because of the hand pouring method involved.
The advantages of rigid boards include most of the above plus the highest "R" value rating. This insulation is made primarily from polystyrene, polyurethane, phenolic foam or polyisocanurate. These products retain no moisture and are applied mainly below grade with interior/exterior uses. There are many other types of insulation but we have kept to the practical upgrades for home applications only.
We recommend qualified tradespeople do all tasks, as they offer quality materials, proper installation requirements and a written guarantee.
Know that, for peace of mind, the care and attention you give your home will serve you well year after year and in comfort.