We are putting up new sheet rock in our converted garage and plan to install new insulation in the exterior walls. I am wondering would it be a horrible bad thing to put new insulation in on top of the stuff that is already there? Im planning on getting 5 or 6 rolls of the R19 pink stuff from Lowes and putting that in Im just not sure if I can put new on top of old would that help or be a problem?
I probably wouldn't. Fiberglass batts work best when not compressed. Maybe that's not an issue but I'd start with a new slate. Any pics of what's there now?
Really depends on whether the existing is faced or not.. facing is the paper on one side acts as a vapor barrier, really not a good idea to have that in between insulation as it collects moisture and can mold..
Heres a few shots of the insulation thats in now some of it is in good shape some is torn and some is just not there. I figured since the walls are open why not put in new insulation especially since I have no idea how lod this stuff is. Is R19 good for an exterior wall? I cant find anything higher that is made to be used in walls.
mattjm1017 r - 19, is standard 5.5" stuff, designed to fit in 2 by 6 construction.. . it is to building code.. A couple of questions.. why are you replacing insulation? was the room cold? what is budget? First instinct if budget is tight.. would be add new pink were torn or missing and put some iso- board over that bare concrete block.. Concrete has next to zero insulating value... or is there blue board on outside.. Want to help but replacing old pink with same amount of new pink isn't going to impress you with results..
The room does stay colder than the rest of the house even with two new vents and a return out there. Budget isn't to tight but I can't afford the spray on insulation. The outside of the house is brick and it has that black fiber?board on it. We are planning on putting some decorative tiles up on the block parts. Whatever we can do to better insulate this room would be great keeping in mind that some time in the future but I don't know when we want to put a small wood stove or pellet stove out there.
From those pics, adding isn't an option unless you go with a pink board (extruded poly) over the studs and before drywall. But that messes with the windows jambs, etc. Is that material fiberglass inside? If so, Canadian border VT makes some good points about whether it's worth it to replace. Obviously the vapor barrier has been compromised. You can get a high performance batt that improves it, but for a 2x4 wall you only go from a r11 to r13 or r15. Pretty minimum gain for the investment. Money is no object, then go new. Budget an issue replace whats bad. Assuming it is fiberglass that is.
Oh and that knee wall as was said is a big issue unless it's insulated outside. Even so furring it out and insulating it would be a nice gain for you.
Looks like you've got some 2 x 4 framing in some of the pics above.... That should be R-13/15. I also notice none seems to be stapled to the "face" of the studs. Don't know if you did that or it was like that when you exposed it. My take on that is that the "flaps" should be stapled to the bare face of the 2 x, to provide moisture protection on that face(it will eventually stain the finish side of Sheetrock), and to keep from squashing the actual insulation between the 2 x's (a sort of pressure fit). That tucked insulation is thereby "compressed" and diminished in its capacity to fill the stud cavity with insulative "air." Just my $.02 mattjm1017 .
While you have the wall open grab some incense and test the walls for air leaks, especially along the block to stud wall joint the and around the window. It's not just poorly insulated walls that are an issue but air leaks too.
I'm pretty sure its fiberglass its yellow and feels like fiberglass. If you look at the last two pictures on the left hand side you can see the black board I'm talking about it is all over the exterior of the house under the brick its on that wall because it used to be an exterior wall.
Could you fir out for an R-19? Would be a hassle to extend jambs(not too bad tho) but you'd get some 2" more per bat in thickness. Combined with schlot's solid reminder about air penetration, nipping air movement and adding a thick fresh pink....blanket, that would be "the exit side of the cat!"
So is the general consensus that it would be a waste of time and money to replace all of it? As far as the block parts go I can put some of that blue board up and then the tiles I like that idea .
No I can't really extend the jambs any then I'd have to reconfigure the windows and that's not an option right now. I will check for air leaks and see what I can do to seal them up though.
