Straw Bale Roof Insulation

The two layers of batts and 3 of rigid foam andrew describes would be about 240mm deep for r57.

Straw bale roof insulation.

On end or flat. Straw enables vapour permeable walls which are locally sourced and have low impact for construction. In a straw bale house these bales form the walls insulation and framework all in one with some additional support from wooden beams wherever they re necessary. However if you want to use bales you can use an assembly that looks something like this.

The typical straw bale is bound twice and is approximately 900mm long 350mm high and 450mm deep. Personally i stick with light weight insulation materials in the roof and leave the bales for the walls. A good time to use this roof is obviously when the budget is tight or if you want a larger exposed side of the structure as in a greenhouse or in cooler climates. This construction method is commonly used in natural building or brown construction projects.

Bales of r40 with ceiling airspace anticon then roof would rate somewhat above r40 and the standard r38 andrew talks about. The density of the straw how long the straw itself is as well as the moisture content how well the gaps are filled between bales and other things like how it s stacked. Are there any very long spans. Straw bale construction is a building method that uses bales of straw commonly wheat rice rye and oats straw as structural elements building insulation or both.

Strawbale insulation is tightly packed and 18 thick. For straw bale this can pose a problem in keeping the walls free from direct moisture. If you re wondering what the r value of strawbale construction is then it depends on a few things. Make sure it s in good condition no rot termite damage cracked boards etc.

A straw bale is very suitable as infill nonload bearing insulation for timber frame buildings with either an external render or timber rain screen finish. First you need to check the strength of your roof system. Owen geiger yes you can use straw bales as roof insulation. This implies that bales r factors would be considerably higher.