Recently had my roof shingles replaced and as part of that the crew had to replace a bunch of plywood roof sheathing. Didn’t phase me, it’s a 50+ year old roof and probably 20+ years since the last time shingles were added.
Just went up into the attic recently and…WTF:
All the insulation strips that had been between the roof rafters were down and left in piles on the attic floor.
As far as I can tell they just kicked down the insulation strips from above as they replaced roof plywood and just left the insulation strewn on the attic floor. Not so much as a “hey you might need to replace your insulation”. Thanks gents…
So now I’ve got a mostly un-insulated roof. The insulation that was removed is in rough shape - a lot of the strips have the side staple portions ripped up, and a bunch of them have the paper backed away from the fiberglass. It was all probably insulation from the 70’s, so not great quality compared to modern stuff, but it was better than nothing.
Should I make any effort to try to put the old stuff back up (is the any alternative method to affixing it beside stapling?) or just haul it out and get new insulation?
Well, I just learned something after doing some searching - I guess the roofers were doing me a favor as roof-rafter insulation in an attic with a floor is NOT recommended.
Apparently you insulate the floor of the attic, but not the roof.
Guess I’m just going to take the batts that they kicked down and overlay them over the existing batts on the floor of the attic.
Actually, is the attic finished, does it have a floor? If the attic is just storage, insulating the floor instead of the rafters makes upstairs rooms warmer. It is a million times easier and usually less expensive since you are covering a smaller area.
Also, I might be inclined to use spray on foam insulation for a quick fix.
If the attic is finished and say has dormers and a regular floor, (home office, sex dungeon, arts and crafts room, etc, then the rafters should be insulated.
1st/Ground floor - concrete slab, 2 car garage/workshop/1 car garage, concrete block walls, unheated/uninsulated. One utility room with washer/dryer/work sink/tankless water heater.
2nd floor - Living area - wood frame, windows, heated.
Attic - Unfinished, has HVAC/AC system in it, ceiling vents that blow down into 2nd floor. Accessed via pull down/folding staircase. Has some bits of plywood around for walking and to support the HVAC system, but that’s it.
After reading your first post, that was exactly what I was thinking. You don’t insulate the roof rafters if there is a attic floor that is insulated from the living space below it.
So yes, they did you a favor.
And yes to your second thought. Just take those batts from the rafters and lay them on top of the existing floor insulation. That will give you more benefit then throwing all of it out.
If you want to insulate it, there is a foam insulation with the air space built in. It ensures the ventilation from the soffit to the ridge vent. Then you insulate on top of that..Baffle