R-30 insulation in a ceiling framed with 2x8's
2017年5月7日 · Hey I need to put r-30 insulation in a ceiling framed with 2x8's regular fiberglass insulation requires 9" of space (2x10 framing). I have looked into spray foam which is pricey for 330sq ft it is $3,000 and rigid board at 4.5in (r-30 value) is $1,500 for the space.
Compressing fiberglass batts - DIY Home Improvement Forum
2023年3月24日 · If you compress R-21 insulation into the space of an R-15 batt, the R-value will be somewhere between 15 and 21. Estimates of the actual R-value vary, but are mostly around 17. Reactions: duffman56 and Bud9051
Does mineral wood insulation lose R-Value due to compression?
2016年6月19日 · The chart does not give values for compressing 12" down to other thicknesses. As for the r-value increasing as you compress it, go to your chart for r-13 for 3.5" at the bottom. It gives you 3 options, 3.5", 2.5", and 1.5". If you divide the r-values shown for each by those depth options you get: 13/3.5 = r-3.7 per inch 10/2.5 = r-4 per inch
Rigid Insulation Installation (R-30) - DIY Home Improvement Forum
2008年2月3日 · standard R-30 batts and ventilation. A vent baffle should be installed between the insulation and roof decking to ensure that the ventilation channel is maintained. If roof framing provides insufficient space for required insulation, higher insulation values can be obtained, by either framing furring strips (that permit additional
What R-Value Insulation is This? - DIY Home Improvement Forum
2023年9月1日 · Insulation rated as R-13 will give you an R-value of 13 in a 3 1/2" wall. An R-19 insulation will get you an R-value between 14 and 15 in a 3 1/2" wall. Stuffing R-30 insulation in a 3 1/2" wall, if you could manage it, would only give you an R-value of about 10, if I remember the chart I looked at a while back.
R30 ceiling insulation with 2x4 roof trusses - DIY Home …
2008年4月4日 · Fiblerglass is an ineffective insulation with many problems. You will get total coverage and minimize the thermal shorcircuiting caused by the wood. If you are into the old R-value concept cellulose is also better. Only the pink panther thinks it …
Does rigid, thin R30 insulation exist? - DIY Home Improvement …
2010年6月12日 · Hello there. I am exposing the beams in my bedroom. I was assured that insulating it with R30 rigid thin insulation would be no problem. My contractor says no such thing exists. Can anybody tell me where to get it if it exists? Thanks, Kai
Vapor barrier + floor insulation on shed/office
2019年11月3日 · But I'd only be able to get R-19 insulation (6.25") with 6" joists (plus a little room beneath the shed. R-30 insulation looks to be 8.25" and even the R-30 Rockwool is 7.25". But I could maybe add some height to the joists by ripping down some 2x4s and nailing them on top to gain an extra 1.5" for the insulation...
1960's era fiberglass insulation R value? - DIY Home Improvement …
2009年6月17日 · That was installed before "R" values were a big deal. It's likely to be about the same R value per inch that fiberglass is today. About 3.1 per inch (+ -). If you are leaving it, don't insulate in front of the foil. The foil is the vapor retarder and needs to be on the warm in winter side of the insulation mass.
R 30 Insulation in Walls - DIY Home Improvement Forum
2011年12月11日 · I would use Roxwool, or Wet application dense pack in the wall space, vs. conventional insulation batts. Reason being, is that air moves too much through regular batts, along with noise. Reactions: Windows on Wash