Determine R-value of existing insulation

[Matt Williamson]

I have a family room in my house that is basically 3 outside walls. One wall faces my uninsulated garage, another the side of my house and the back wall is the back of my house with a florida room. The back wall also has a woodburning fireplace. There is wood paneling lining all of the walls. The room is very cold in the winter and I think more insulation would help. The existing stuff looks very thin. It's maybe 2" thick and it looks like yellow fiberglass type with foil backing. I'm ripping down the paneling and putting up drywall and I'm trying to determine what the existing R-value is and what I should add to make it a little better. I know the wood fireplace is a huge air draft that just sucks heat out. I plan on putting in a gas insert to make that more efficient. Here is a link to a couple of pics I took of the insulation.

Click the thumbs to get a full size pic. What would be my best option for this room? Can I just add more over top of the old or should I replace it with something better altogether?

TIA

Matt

[Tony Hwang]

Hi, Where do you live? Is the stud 2x4 or 2x6? FP place may be lot of heat than heating the room depending what style.

[clare]

I'd pull it out and reframe inside - makes the room about 7 inches smaller one way, and 3 1/2 the other - with 2X4s and put in new insulation. Either rock-wool comfort batts or styrofoam SM and rock-wool. Matts - not blown wool. (Roxul is the common supplier up here in Canada) Fiberglass would be second choice. Blown urethane foam is also an option - more expensive but "airtight".

Don't be tempted to leave the old crap in.

[Matt Williamson]

I'm in the North East. Western NY area. That room is framed with 2x4's. So, is the R value of the existing insulation 3.2 x the thickness of the insulation?

[Tony Hwang]

Hi, Around 4 x thickness and if batt is compressed or moist it loses R value. They don't build houses any more using 2x4 studs. It's 2x6 now. I live in Southern Alberta. Rigid styrofoam panel has higher R value. And if your FP is not air tight type I'd convert it for heat gain than loss. Here we all use NG direct vent FPs now.

[benick]

It's probably an old off brand 3 1/2 inch R-11....Replacing it with Owens Corning 3 1/2 will bump it up to R-13...The foam that is sprayed on would get you where you want to go but it isn't cheap but compared to any framing out or adding syrofoam panels and the wiring problems that might bring as far as moving the boxes out , it might be worth it.....You won't have enough wire in the box to extend it out more than an inch or so at MOST....I bet if you did a good job with the R-13 including insulating behind and around the outlet boxes , poking it around the windows good and foamed all the nooks and crannies with a can of spray foam it would be fine AFTER you install the Gas insert into the fireplace which I think is the reason your room is cold..JMHO........

[Jim Elbrecht]

For w-NY you can sure use some more insulation in those walls. I agree with the Canadians who suggested making the wall thicker & re-doing the insulation.

But if this is on a slab- your first thought will be to dig around the outside and put in some perimeter insulation. . . . And if it is full of windows- you want to re-think them. . . . and if there is no insulation overhead, you need to get some there.

THEN. . . do the walls.

Jim

[ransley]

It might be about R 10-12, minimum code might be R15 and optimal near R 30, Best is R7" sprayed on foam for R 24 and no air leaks. The fireplace is a looser up the chimney, I could not find a true sealing door for under 1000 so I got a chimney cap that closes but still had alot of cold air comming down. I took steel L channel and screwed it to the frame, then R 14 foamboard and put on Magnetic Tape, I painted foamboard to match and just remove it when I want a fire, just the foamboard cover warmed the room noticably. Your room was designed to minimal standards, you can redo it so you will save alot every month heating and cooling it. Not all foam have the same R value, some are R5"

[Mark]

i agree about the fireplace being a major source of cold...don't forget the ceiling as well.. you didn't say if it was 1 or 2 floors...

Mark

[trader4]

:

I don't see the significance of determining the R value of 2" of existing insulation. You want to put the max amount you can fit into the wall. Choices are either add to it, or pull it out and start over.

[ransley]

te:

I guess to figure why he is cold. In cold areas the 3.5" he has to work with he cant get a high R value with fiberglass and such, many here now use 2x6 walls, and foam. Last winter I saw -20 and this is the coldest summer, maybe a record, im not looking forward to my Ng bills comming soon, Chicago is now 58, and its August.

[clare]

Styrofoam SM is R5 per inch - so roughlyR20 to fill cavity. Roxul is R14 for 3.5" batt and moisture does not degrade it like fiberglass.