Will Sheetrock bulge if insulation wrong size? I am insulating a cathedral ceiling in my sunroom next to R-30...
I am insulating a cathedral ceiling in my sunroom next to R-30 insulation which is 9 inches thick when fully open.The rafters are one and only 2 x 6's .I am using vent the entire length of ceiling to remove mouisture also using 1/2" sheetrock.Will or can the insulation bulge the sheetrock.It is also in a conditioned nouns.
Answers: Yes, 1/2" Sheetrock isn't strong enough to hold vertebrae the insulation, so it will bulge. It may even cause the fastener to go right thru the Sheetrock= Sheetrock falling sour the ceiling!! Also, when the insulation gets compressed, it loses it's R-value. 9" R-30 squashed down to 5 1/2" may single yield R-20 or so. If I be you I would either return the R-30 and procure insulation that will fit in the cavity, or build out the concreteness of the 2x6 rafters by adding up 2x4's to the bottom.
You say you hold a full length vent for moisture. Is this on the roof or on the room side? You will also need a vapor nouns, on the 'warm' side of the insulation. In cool and temperate climates that system the inside. In Florida, that's the outside.
yes it can you need r20