Insulating floor for a house on stilts

[Charles Theriault]

Hello all

Do any of you have suggestions on how to insulate my floor. I am building a one story stawbale home ¨Post and beam To be built on stilts 3 feet off the ground.

Not sure how to insulate floor. Floor to be built with 9x9 beam construction at every 6 ft square covered with 8x10 tamarack planks 2 inch thick. Would like to build as green as possible.

Thank you

Charles Theriault

Kedgwick New Brunswick Canada

 

[mudmixer]

You are attempting to adapt a very old construction method to a new climate. It should be a challenge.

Since you are no stilts, you may be losing some of the advantages of strawbakes including mass and thermal moderation from the earth.

If you are open underneath, you may be forced to go the simplistic, advertising driven "R-value" route since you can expect will probably have cold air under your home floors during the winter.

The use of materials to block cold from pentrating under a living space has been proven in dry cold climates. In our climate (lows of -20F to -40F) uncoated strae bales were commonly used toprevent the intrusion of cold air under a home and to retain the heat from the earth.

You could follow the same process by enclosing the stilt area with straw coated in the same manner as traditional straw bales. You will have to be able to provide some vents that can be closed in the winter.

This has been proven but you may have much more moisture and humidity, which is the enemy of straw bale construction.

 

[inspectorD]

As Mudmixer suggested, this is a tough question to answer. The dynamics of a straw bale home work differently than any other.
You will need to seal the entire underneath with a vapor barrier so the moist air does not migrate into the structure from underneath. I would also have an air exchange system in place to create positive pressure inside the building.
Even telling you this may not be good advice because we cannot see the home, or the conditions of where you live. If you live in a wet part of the country it will not matter what you do.
Closed cell organic and green spray foam is also available. This would be my first choice.
Someone to contact would be www.buildingscience.com for their suggestions on your particular house. You can even get them out for a paid consultation. I would suggest you do this and pay the money now for the right advice. Because it will absolutely cost more to repair it, and get their advice after the fact about how it should have been done. I have been a builder for 25 years, and used them more than once with excellent results.
Please tell us what you decide, and If you contact them as to what they say.