WHY AIR SEAL?

Drafts...

Have you ever put your hand up into a soffit to fix or add something and felt the air just circulating through the soffit?  Not only is it common with standard draft stopping but it is dangerous!  If a fire were to start on one end of the house it will chase through those areas very quickly.  That could be catastrophic!  The airflow doesn't help the heating of your home either, that air is coming from and going to somewhere, usually the outside.  The Icynene Insulation System is an air seal and because we are able to get it into very small spaces, we can effectively stop air flow the way it should be done.

How about turning on that light switch on a cold, windy day.  If the air flowing through the switchplate doesn't convince you that you have a leaky house, maybe nothing will.  Icynene easily gets in behind all Electrical outlets, plumbing pipes and any other awkward framing situations to effectively seal normally drafty areas.           http://resourcecenter.pnl.gov/cocoon/morf/ResourceCenter/video/404

Gap Filling...

Have you had a framer that left gaps and holes in your substrate or just done a less than tight frame?  While we cannot correct their workmanship, we can seal up all of these air leak areas.  With a 100:1 expansion ratio we will seal the house up tight.

How about a foundation that was not level or is wavy on top.  The standard roll insulation for the sill is not intended to fill those gaps and it dosen't.  The foundation seal and box joist can be one of the worst air leak areas of the home.  When we spray foam, we bridge from the top of the foundation to the underside of the floor decking.  This seals any unseen gaps not filled with the standard sill seal.

Most codes require the Insulation Contractor to seal the bottom plate to the floor with a foam product.  While this will help in theory, it doesn't work well since most of the foam gets knocked or peeled out of the way for other trades like the drywaller or flooring contractors.  To build your house better, when the walls go up, use a thick bead of subfloor adhesive between the bottom plate and the subfloor.  This will form a good air seal so that if the foam is removed when it shouldn't be, you still have a seal.

When insulating around windows and doors we typically use very low expanding window and door soft foam.  Always needing to be mindful of the window manufacturer's warranty specifications.  Fiberglass chinked into the gaps does not stop air flow.  Foam is best, however, it needs to be done so as not to bow any jambs.  Also, as the Builder you need to be sure that you shim the window up at least 1/8" off the sill plate to allow for insulation.  It is also good practice to use a caulk or adhesive bead under the door thresholds for the air seal.

As for the final building component that needs proper insulation, the roof, there are a few ways to go.  Spray foam to the drywall after installation or an unvented attic assembly.  There are a few pro's and con's to each but either is superior to cellulose or fiberglass.

First, spraying to drywall is good when a house has a steep roof and is very detailed.  Since it uses less material and will cost less.  When using this method, a catwalk will be needed for future attic access.  With this traditional vented attic there is still a chance for snow to blow into the attic system having the potential for water damage.  If this were to happen, rest assured that Icynene does not wick water making a leak easier to find, and it will not distort or loose its shape when wet and then dried.  This system is not practical in low pitch roofs where a worker cannot enter with equipment.  The envelope in this application can still be complete and effective.

Second, the unvented attic assembly is a code approved variation on attic insulation.  It can be properly done using foam because of its air seal properties.  Insulation is sprayed directly to the underside of the roof plywood in order to encapsulate the entire structure.  There is no ice damming in the winter using this method since there are no longer large temperature swings in the attic.  Air movement is also stopped so moisture cannot travel up under shingles.  This method works well on lower pitch roofs and vaulted ceililngs.  It frees up all of the attic floor for easy access.  Convenient for mechanical/ductwork, future electrical work or possible storage.  Also, as stated before, Icynene does not wick water, so if there is a roof leak, the location is easily identifiable.  An extra benefit to the builder is that the insulation is done in one step, which in winter month construction, is convenient since the envelope can be heated for the other trades without blowing the heat right out of the vents.