Straw Bale Roof Insulation

Strawbale insulation is tightly packed and 18 thick.

Straw bale roof insulation.

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. Are there any very long spans. The typical straw bale is bound twice and is approximately 900mm long 350mm high and 450mm deep. 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.

Straw enables vapour permeable walls which are locally sourced and have low impact for construction. On end or flat. 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. The quality of insulation that a straw bale wall provides depends on a number of factors including the way the bales are stacked the way the bales mesh with the roof s insulation the type of post and beam structure or if loadbearing the type of top plate the type of plaster used the quality of the plaster work and the design of the house itself among many others.

Personally i stick with light weight insulation materials in the roof and leave the bales for the walls. 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. 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. This implies that bales r factors would be considerably higher.

Bales of r40 with ceiling airspace anticon then roof would rate somewhat above r40 and the standard r38 andrew talks about. The two layers of batts and 3 of rigid foam andrew describes would be about 240mm deep for r57. If you re wondering what the r value of strawbale construction is then it depends on a few things. This construction method is commonly used in natural building or brown construction projects.

A bale is 360mm deep. However if you want to use bales you can use an assembly that looks something like this. For straw bale this can pose a problem in keeping the walls free from direct moisture. First you need to check the strength of your roof system.