strawbale venting system

Active system to use on strawbale. When using a interior vapour barrier a constant flow of air on the bales will assure low moisture content. In cold climates it's the different tempratures that meet in a thermal mass like insulation. Phase change occurs in the h2o molecules or condensation.This is why the vapour barrier is so important,because moisture from the interior should not be allowed in the thermal mass. The condensation forming from the differental temprature will be closer to the exterior. With air constantly moving over the bales moisture should not accumulate. Any imput is welcome on this subject.

Category:

Howto & Style

Tags:

• strawbale
• moisture
• mold
• homes
• insulation
• sustainable
• building

[Duboisi]

I realy liked this idea. Especialy as I am hoping to build a haybale house in a few years. As you are infact adding a second outer shell, it should be slightly better insulated than a normal bale house.

Only objection is that PVC tubes seems a tad expensive for such a task. Would belive that 1X1 wooden beams would do the same job at a cheaper price, and be flexible enough tofollow the curves. It should also make it easier to fasten the outer netting, as you would then be able to use cramps.

[skilletsduc]

The ribs should be inorganic as there will be condestate on the inner portion of the shell. I have been monitering % of moisture the bales started out at 10% and 3 years later is 6-7% a very good direction.

[AELMYRCAamorica]

Can this construction be applied in .-15 degree snowy locations.

[skilletsduc]

Are you refering to the stucco finish? If so that would be too cold even with anti-hydro as a anti-freeze.

[AELMYRCAamorica]

I live in Norway, can i build such a house here...

[skilletsduc]

Sure This design is for extreme conditions. The advantage of the geodesic sphere is the strength, the shell underground is 2" thick. After 5 years and temps from -20 to 85F there are no cracks or faliures,despite all the loading from the framing of floors and trucations. I am trying to get funding to float one. Peace

[pupplesan]

Respectfully you seem to overlook my point: for insulation to function there must be very little convection (air movement) WITHIN the insulation and especially from the warm face to the exterior. What you are describing is a system that allows cold outside air to passively infiltrate underneath the insulation and up against the interior wall-vapor barrier. This means that the interior wall is facing cold outside air and that all the insulation has been short-circuited.

[skilletsduc]

Actually the venting occurs on the outside. A continous vapour barrier in on the inside. This is the normal location for the vapour barrier. If anyone is building without a vapour barrier you are putting your family at risk from all the composite building material they use now ie, OSB, TJI, particle board not to mention radon cadiumn and lead that may be in the soil,see clip on crawl space mitigation. Thanks for the comment, build safe

[pupplesan]

If you are creating a ventilated gap between the interior of the home and the straw-bale insulation, then all the heat in the home will get convected away while it is 'underneath' the bales rendering the insulation worthless. While I share your concern for moisture infiltration, unless I am missing something, this is not a good solution.

[zml59]

your worried about moisture from breathing? stop breathing!