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I&S Insulation Maine's leading installer of spray foam, cellulose and fiberglass insulation
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New Construction
When building a new house you have the opportunity to do it right. You will probably never have this opportunity again so it is important get the envelope air tight and well insulated during construction. We feel that a combination of dense packed cellulose and closed cell polyurethane spray foam is the most cost effective way to achieve this goal.

The recommended insulation values for this climate zone are R49 in the ceiling, R20 in the walls, and R30 in a floor over a cold space. There is an exception that allows R38 in the ceiling if the full R38 thickness extends over the top wall plate. The interpretation of this varies from town to town so you should always check with your local code enforcement officer. If you plan to have cathedral ceilings in part of your new house, this interpretation can make a significant difference in the cost to insulate the structure. We can exceed the R38 requirement in a 2x12 rafter with cellulose. In order to achieve R49 in a 2x12 we need to use closed cell foam which makes the cost 2.6 times higher!

The Energy Star air tightness requirement is less than .5 air changes per hour natural. A house built to this standard will probably require some amount of mechanical ventilation to provide fresh air for the occupants and remove moisture. A Heat Recovery Ventilator (HRV) should probably be included in the design. Also, naturally vented combustion appliances will not operate properly and should not be used.

Here are some pictures of a typical new construction installation. You can click on any of the images for a larger view.
Dense Packed Cellulose 2x12 Slopes R41

Insulweb is stretched across the face of the rafters and attached with small staples. Then it is "Lip Stapled" with 1" crown staples to pull the fabric tight in each rafter bay. This is important to keep the bays flat to facilitate the installation of the drywall.
6" Closed Cell Spray Foam R39 in 2x10 Slopes

In areas with complex framing or rafters that are less than 2x12, we prefer to use Closed Cell Spray Foam. This ensures that all the little nooks and crannies get sealed and allows us to get the necessary R-value in a smaller space.
Dense Packed Cellulose R20 in 2x6 Exterior Walls

This picture shows one of our skilled installers blowing cellulose into an exterior wall cavity. The cellulose is blown in at a density of approximately 3.2 pounds per cubic foot. This density is higher than the natural settled density of cellulose thus ensuring that the cellulose will not settle over time.
The cavities to the installers left are part of an interior wall. Fiberglass bats have been installed as sound insulation.
Fiberglass Bats in Interior Walls for Sound Dampening

Here one of our crew is installing unfaced fiberglass bats in an interior wall. We recommend fiberglass for sound dampening around bath rooms, bed rooms and mechanical rooms. We also use it in floors under radiant heat.
Fiberglass bats can be used to insulate the thermal envelope and still meet the code requirements. It does cost less, but does not provide any air sealing benefits like spray foam or dense packed cellulose. In our opinion, it does not perform nearly as well and will end up costing you more in the long run due to increased costs to heat the house.