Insulation goes in

The insulation comes in bails that are emptied into a large blower. The guys had a bit of trouble unclogging the hose and getting the pressure high enough to blow the insulation properly. It then leaves the back of the truck and into a long plastic hose that leads to the wall cavities.

A second worker is in the house going up and down the scaffolding and filling the wall cavity defined by the wall trusses. The cellulose really blows everywhere. It's easy to sweep up, though. I guess the cathedral part was a little tricky to insulate. They had to climb pretty high up and get the hose above the rafters.

Insulation arrives

Okay, we're reaching back to June for updates here. The project has slowly been running its course here. Outside, nothing much has changed since the porch. Most of the changes have been inside so we can get moved in. The first big change was the insulation. The truck arived hauling the trailer at the same time the tile bed was done.

We used high density blown cellulose. Cellulose is recycled newspapers shredded into tiny bits. It is treated with boric acid to keep out vermin (boric acid is non toxic and acts as a dessicant to dry out any bugs that may enter, and also soaks up any moisture that may enter the walls). They also treat he product with fire retardant.

Insulation: before and after

Here's a good sequence of the insulation going into the bedroom wall. The horizontal furring is nailed to the wall trusses and holds the plastic vapor barrier in place. Red tape seals the different flaps of vapor barrier. The insulation is then blown in between the vapor barrier and outside sheathing.

Finished foundation

Here are a couple of pictures of the insulated foundation. It gives a good idea of how we did it. It's about $2000 of stryrofoam SM, but it will pay for itself over our lifetimes in heat savings. The aluminum coating on the interior is very visible, held in place by tape. This may be overkill, of course, but the stuff is cheap. It's also effective. Lisa said it really heated up on the inside as she was finishing the job.

In the first picture, Kitty inspects her new catwalk. It will not be one for long.

The second picture shows the sunset over Spruce Hill, with the access for the septic tank in the foreground.

Foundation insulation continues

Lisa points with pride to the fine job she's done insulating the foundation (not to the post anchor). In this photo, the outside is finished and the inside is in progress. She has since finished the inside.

Today, she insulates the pilasters and I line the inside with aluminum foil vapor barrier. Aluminum foil vapour barrier reflects the heat radiation emitted by the crushed stone into the space between the crushed stone.

Did I mention that she's very handy with a knife?

Insulating the foundation

Here's a picture of my lovely wife and assistant cutting 2'' Styrofoam SM boards for the foundation. She's very crafty with a knife. We are installing 4'' on the outside and 2'' on the inside. Today we nailed it to the sill on the outside. We'll need to nail into the concrete on the inside. Hello power drill.

This gives us R-30 insulation value. Overkill? Not with a radiant slab. The temperature of the slab will be maintained at 75 C (22 C) whereas the temperature of the air will be closer to 65 F ( 18 C) (for very toasty toes). If you want to keep the heat in, you need to insulate the slab. Moreover, with a solar system you want to store solar heat from the day and summer through the night and winter. You need to insulate below the slab as well.

Wall system

The wall system was proposed by William Lemaistre, the timber framer for this project; 8"Posts are supported by 10" sill beam.

The outside wall consists of a system of vertical trusses resting partially on the foundation, but mostly protruding out above the foundation. They held together by horizontal furring and anchored to the posts, sill beams, and rafter plates. The wall cavity is filled with blown cellulose insulation for and R-32 insulation value. Thick walls allow for deep windowsills, but will hang far over the foundation walls.

The frost wall is 8" thick and at least 16" tall. It is anchored and poured directly on the the impermeable rock of the building site and supports the load of the posts. 4" concrete or cinder-block pilasters support the load on the posts on the inside of the foundation. The foundation is filled on the interior by crushed stone and a top layer of sand to support a poured-concrete hydronic slab.

The frost wall is insulated on the outside by at least 6'' of polystyrene board and a finishing wall that will bring the below-ground wall system flush with the above-ground wall. The fill and the frost walls themselves act as heat sinks for the entire house and require R-Values higher than a standard foundation.

The sill system consists of 10'' thick by 6'' high beams that rest mostly on the frost walls, overlapping slightly with the pilasters and on the inside of the walls. The beams act as forms for the 4'' hydronic slab, providing extra R-14 insulation in addition to the R-32 wall system.