Radiant Vs Rigid Insulation Or BOTH How Much Of Each

wolftrap

I have a client with cinder block walls with a brick veneer. The walls are sheet rocked on 2x4s laid flat. Noticed I did not mention anything about insulation. We are planning to pull down all the sheet rock and add insulation and resheet rock. The question is how to get the most insulation with the least amount of space. He is willing to go more that the 1 ½” of the 2x4, may be 2x4 on edge. One site said the best way is to put up 2” of rigid insulation boards then ¾ furring strips then foil/bubble/foil Radiant Insulation. Then ¾” furring strips then sheet rock. Is the 1 ½ used up by the foil and furring strips better used with thicker rigid board?
Another site said 2x4 on edge and fill with 3 ½ “ of closed cell foam. Everybody I ask says that the thing that they sell is the way to go. Each seems to have a good argument. What are your opinions, is there any non-biased testing outfit out there?

genecarp

if he is willing to loose 4 '' overall, dont overcomplicate it, frame a 2x4 wall the traditional way, use r-15 kraft or foil face, then sheetrock. are there other ways to booste r value , yes, add a layer of 1/2'' rigid under the rock, use unfaced r-15, or just score the paper, tape the rigid joints, this will add another 3 or 4 value. welcome to ct

__________________

Jake Stevens

Most all closed cell insulations have a R7 per inch but than you will need a air exchange because it will be to tight. I would leave the 2 X 4's on the wall and not take the risk of breaking up the blocks. A 1 1/2 blue board is about R8 or R9 with a Radiant insulation over that which has a R fator of R8 to R10 and then install new strapping over that and sheetrock

EPSFOAMCENTER

If you are looking for insulation sheets or even foil faced insulation sheets I can help. Let me know what you need.