Trying to insulate new wall between crawlspace & furnace room; need discussion

OK, I'll admit this is a little involved to set up the situation in order to give important details. Fairly standard ranch in North Carolina, but it has large room downstairs that can exit out back to ground level. Also, a furnace room at the bottom of the stairs, was open to the crawlspace, approx. middle of the length of the house. There's a block wall about 4 ft tall separating the furnace 'room' from the crawlspace, and a passthru in the wall so you can step into the space. Crawlspace has a layer of heavy plastic on top of all the dirt to keep down the moisture. Recently remodeled the room, so we could move washer & dryer in there, which included a full height stud wall in front of the block. Wood 2x4's & standard drywall. Currently no insulation on the stud/crawlspace side, plus a fairly large gap above the wall top plate & the floorjoists and subfloor above it. Lets in a fair amount of cooler & moister air into the new laundry room. OK, I want to insulate the stud wall to keep the laundry / furnace room a litle warmer & dryer. How do I handle the moisture too? Do I need a vapor barrier? and on the drywall side of the insulation between the studs, or the crawlspace side of the insulation? And should I maybe put a layer of 1/4 inch plywood on the crawlspace side to protect that side of the insulation? submitted by /u/Parking-Fix-8143 [link] [comments]

Mar 8, 2025 - 05:13
 0

OK, I'll admit this is a little involved to set up the situation in order to give important details.

Fairly standard ranch in North Carolina, but it has large room downstairs that can exit out back to ground level. Also, a furnace room at the bottom of the stairs, was open to the crawlspace, approx. middle of the length of the house. There's a block wall about 4 ft tall separating the furnace 'room' from the crawlspace, and a passthru in the wall so you can step into the space. Crawlspace has a layer of heavy plastic on top of all the dirt to keep down the moisture.

Recently remodeled the room, so we could move washer & dryer in there, which included a full height stud wall in front of the block. Wood 2x4's & standard drywall. Currently no insulation on the stud/crawlspace side, plus a fairly large gap above the wall top plate & the floorjoists and subfloor above it. Lets in a fair amount of cooler & moister air into the new laundry room.

OK, I want to insulate the stud wall to keep the laundry / furnace room a litle warmer & dryer. How do I handle the moisture too? Do I need a vapor barrier? and on the drywall side of the insulation between the studs, or the crawlspace side of the insulation? And should I maybe put a layer of 1/4 inch plywood on the crawlspace side to protect that side of the insulation?

submitted by /u/Parking-Fix-8143
[link] [comments]