Insulation...preferences?

[Eric Adams]

Anyone have preferences on what insulation they used? I have thought foam sheeting insulation but have some extra R11 Owens Corning pink fiberglass stuff in rolls. I know I'd have to compact the roll stuff.

Recommended type?

Pros/Cons?

[Eric Adams]

Almost forgot, is there a good foam sheet insulation that has a shiny reflective side? I hear Mylar ia a good reflective insulator vs heat.

[Arne]

Rigid foam has about the highest r-value. Yes, the silver sides do reflect heat... problem is it doens't bend well....

I'll be using it in the walls, but the curves will have to be some type of flexible insulation.... or, ugh, fiberglass.....

[mikeschn]

Yes rigid foam has the higher insulation value.

If you take the fiberglass and compress it, you actually reduce the r-value.

I used extruded polystyrene and kerfed it, so that it would bend around my curves. It worked great!



Mike...

[Denny Unfried]

On the curves I used three layers of 1/2" polystryene which bends to most any radius. As mentioned a couple posts back the fiberglass batts don't do well when compressed.

Denny

[Chip]

Lowes has a polystyrene flexible insulation,,it bends a bit easier than the pink or blue extruded poly,,you may have to put it in using a couple layers,,the R-value is just under the extruded

chip

[Eric Adams]

Yes rigid foam has the higher insulation value.

If you take the fiberglass and compress it, you actually reduce the r-value.
..

If you compress a R11 insulation would it still have a higher "R" factor than a extruded foam product?

[Chip]

nope,,as you compress the insul the air space is reduced,the trapped air space is what gives ya the insullating value not the fiberglass

chip

[mikeschn]

Another consideration is that fiberglass batting can collect moisture in it. Solid extruded polystyrene doesn't!

Mike...