dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
7379

UHF
All static, all day, Forever
MVM
join:2002-05-24

UHF

MVM

Adding insulation to walls

My house was built in 1962, and has some insulation in the 2x4 walls, but from what I can tell the cavities are not full. I think there's probably a couple of inches of insulation in there. No vapor barrier. I don't know if there's any housewrap, I bought the house in 2004, but it appears to have been resided in 1989, with T1-11 plywood.

One bedroom on the second story is always cold in the winter. It's on the NW side, and get a lot of wind. There's signs of condensation on the walls, and the paint has actually become chalky. I've never seen interior paint get this way.

What are the options for adding insulation? I'd prefer to not have to tear off the drywall. Removing the siding isn't preferred either. Some sort of blown in insulation? Low rise foam?
megamech
Premium Member
join:2014-11-13

megamech

Premium Member

That's correct, the only way to fill it up without redoing walls is to spray it with foam. With that said, I'm not familiar with the condensation issue, and would suggest having it checked by a contractor first, just in case.

tschmidt
MVM
join:2000-11-12
Milford, NH
·Consolidated Com..
·Republic Wireless
·Hollis Hosting

tschmidt to UHF

MVM

to UHF
Since it is sided with T1-11 and the inside is Sheetrock getting insulation into the wall cavity will be a problem. This is typically done from the outside by removing some of the siding, drilling a hole in the sheathing at each wall cavity and then replacing the exterior finish. Obviously that is not going to be an option with T1-11.

Agree with megamech See Profile contact an insulation contractor to see what they recommend.

In your case my guess they will have to blow insulation from the inside, cutting and then patching small holes in the Sheetrock at each wall cavity, but that is just a guess, not my field of expertise.

/tom
18189353 (banned)
join:2014-10-28

1 edit

18189353 (banned) to megamech

Member

to megamech
said by megamech:

That's correct, the only way to fill it up without redoing walls is to spray it with foam. With that said, I'm not familiar with the condensation issue, and would suggest having it checked by a contractor first, just in case.

The only way isn't foam. They dense pack cellulose or fiberglass in walls. They remove 1 piece of siding then drill a hole into each section of wall. Once the walls are filled up they plug the holes and re-install the piece of siding. It's a very easy and common process. Even with T1-11 they do it from the outside then just plug the hole with a wood plug. Obviously you'd have to touch-up paint those spots to match.

From the outside: (most common)
»www.qualityrcss.com/site ··· 228.jpeg
»www.thisoldhouse.com/toh ··· ,00.html

From the inside:
»teplovisor.by/pics/%D1%8 ··· 1%8F.jpg

robbin
Mod
join:2000-09-21
Leander, TX

robbin to UHF

Mod

to UHF
I have a number of houses built during the same time period. Personally, I don't think it's possible to properly insulate a house such as yours without removing siding or drywall. The problem is the old insulation which is about 1 1/2 to 2" being fastened in the middle of the stud space. There just isn't a good way to ensure good distribution of the new insulation with the old insulation remaining in the wall. I would reconsider removing either drywall or siding. Best would probably be to remove the siding, insulate, add foam sheathing, and house wrap.
18189353 (banned)
join:2014-10-28

18189353 (banned)

Member

said by robbin:

I have a number of houses built during the same time period. Personally, I don't think it's possible to properly insulate a house such as yours without removing siding or drywall. The problem is the old insulation which is about 1 1/2 to 2" being fastened in the middle of the stud space. There just isn't a good way to ensure good distribution of the new insulation with the old insulation remaining in the wall. I would reconsider removing either drywall or siding. Best would probably be to remove the siding, insulate, add foam sheathing, and house wrap.

The way I've seen companies combat retrofit jobs is to use thermal imaging. They can see the cold/hot (depends on season) spots in the wall before then insulate until the spots disappear. Obviously removing the siding and redoing it all is better but not often not a financially sound choice.
resare
join:2012-11-07
Greenfield Park, QC

resare to UHF

Member

to UHF
My house from the 1940's was so poorly insulated, found "Fireproof cotton" bats in the walls. I guess back then, it was an option (heating costs were so low back then) The wall cavities were 2x4s, but the 4" on the exterior wall (leaving 2" as cavity). Condensation was everywhere, cold air was felt through the electrical outlets.

Exterior wall is cement blocks with linguee (cement crepit....xcuse my English) exterior finishing.

I chose to go from the inside : gut existing drywall, add a "2x4 wall" inside to be able to insulate and add vapor barrier. Was my only choice, because otherwise I would have no insulation where electrical outlets were (they were kissing the cement blocks).

Well worth it....the rooms are now so confortable. Now my only regret is not being good at mudding drywall (I have great respect for mudders now). Also, I re-did all the electrical setup (outlets every 4 ft), telephone + network. Amazingly I found out that my whole 1st floor was connected to 1 15-amp breaker......crazy !
kherr
Premium Member
join:2000-09-04
Collinsville, IL

2 recommendations

kherr to UHF

Premium Member

to UHF
No matter what type/method you choose (unless it's a near total tear off), it will be hindered by the insulation already there. It won't allow for a full fill. You'd been better off if there was none ....

Coma
Thanks Steve
Premium Member
join:2001-12-30
NirvanaLand

Coma

Premium Member

said by kherr:

No matter what type/method you choose (unless it's a near total tear off), it will be hindered by the insulation already there. It won't allow for a full fill. You'd been better off if there was none ....


I have an older rental duplex built in the 40's that had no insulation, so I went with the blown in cellulose insulation 20 years ago, works great.

UHF
All static, all day, Forever
MVM
join:2002-05-24

UHF to kherr

MVM

to kherr
said by kherr:

You'd been better off if there was none

I agree. And if there was none I could get a rebate from my energy provider to pay for it.

Pher9999
join:2011-07-06
Saucier, MS

Pher9999 to UHF

Member

to UHF
Seen this done many times on This old house and such shows. Inside or out they drill a 2" hole, usually at the top, and middle. They blow in Celulose or "Drip foam" (it's similar to spray but more liquid. Not sure what it's called exactly) They start with the middle hole til they fill to it. then plug it and move tot he upper hole. Each bay has to be done. they know if there is blocking in the wall and change where the hole is. I've seen this before thermal imaging was more common. so I guess they can do that too as they fill.

natedj
Elected
Premium Member
join:2001-06-06
Irmo, SC

natedj to UHF

Premium Member

to UHF
16" o.c. is good in theory but in the field its more like 16" maximum spacing.
My house was built in '63' and I'm just finishing up a bathroom renovation. I gutted it down to the studs and after seeing the framing, it would have been quite a chore to just punch holes in the wall and successfully fill every void between the studs.
I encountered blocking throughout the walls (studs were only 8' tall) I encountered diagonal bracing in the wall, and the 16" o.c rule didn't apply around door and window openings. I'm glad I took the time and gutted.
Here are some pic of how I had to piece the insulation in the wall.









bewhole
I Am Here
Premium Member
join:2000-08-08
Alfred, ME

1 recommendation

bewhole to UHF

Premium Member

to UHF
This is just my honest option on this.(Being a former contractor) I would not have them blow in insulation. Why?? because of what you said about the bedroom upstairs. I would almost guarantee that the only insulation you will find in that wall is
1:wet or has been wet (Roof leaking) Rodents lugging it off or no insulation at all.
2:The paint has mixed with the drywall and turned chalky because of condensation.
3: If you blow in insulation the drywall may just fall in from the weight of the blown in insulation.(Seen that happen before).
This is all speculation sight unseen but I would at least have a contractor come and look at it like others have said.

guppy_fish
Premium Member
join:2003-12-09
Palm Harbor, FL

guppy_fish to UHF

Premium Member

to UHF
Replacing the drywall is the best, easiest and lowest cost solution. Your only doing the outside walls so at most is only 2 walls, maybe 100 bucks in drywall and mud. Your likely to find other issues, that should be addressed when you open the exterior walls open, but your talking a 2-3 day project to pull , insulate, rock and finish what at most is 8 sheets of 10 dollars a board drywall , for houses that nothing

ArgMeMatey
join:2001-08-09
Milwaukee, WI

ArgMeMatey to UHF

Member

to UHF
I have a 1920s house. Brick fascia outside with lath and plaster on the inside. An energy auditor did a blower door and FLIR check and recommended dense-pack cellulose.

In late December (cold weather), an insulation contractor drilled 2" holes in the interior lath and plaster in each stud bay and blew in dense pack. As appears to be standard, they checked while in progress and after, with FLIR, and in some areas drilled additional holes to reach spaces that hadn't filled. For example in some spots there is only one hole at the top of a cavity. In others there were holes between windows, below windows, etc. They rough-patched the 2" holes.

They cleaned up well after themselves and used dropcloths all over upholstered furniture, etc., but I had to do significant prep to cover up and move stuff so it wouldn't get dusty, and clean up cellulose dust afterward from floors, etc. Tedious but not difficult.

The energy auditor returned and did a blower door test and FLIR check again in my presence. I had a list of problem areas from the initial inspection. We reviewed them all and they all looked good, or at least as good as could be expected given the 3.5" cavity.

I had a finisher do the final repair of the 2" holes and texture to match the old plaster. I think there were about 100 holes.

If I had it to do again, I might check out cotton, closed-cell or open-cell foam, but I can't say what would have been the best choice.

In any case, I had no signs of water damage or condensation inside. There is an air space between the brick and the house framing that is covered with rough lumber and tar paper - very old tar paper that is falling apart.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor to UHF

Member

to UHF
Looks to me most of the options were already listed, except the one I've been doing.

What I do is put a 1" - 1.5" solid foam on the top of the drywall, and then another layer of drywall on top of the foam and then fasten them to the studs with long (2.5" - 3") drywall screws. It's somewhat labor intensive, but it's working very well. There are several types of foams, styrofoam is the most well known, but I use polyisocyanurate foam since it has a somewhat higher R value.

A long time ago I did some work on my ex's house, and while it's time consuming, but it's possible to remove T1-11 without any damage, and then put it back. With the siding off, it should be easy to see if there's anything wrong there, and remedy it.
Critsmcgee
join:2011-12-02

Critsmcgee

Member

said by aurgathor:

What I do is put a 1" - 1.5" solid foam on the top of the drywall, and then another layer of drywall on top of the foam and then fasten them to the studs with long (2.5" - 3") drywall screws. It's somewhat labor intensive, but it's working very well. There are several types of foams, styrofoam is the most well known, but I use polyisocyanurate foam since it has a somewhat higher R value.

That has to be a nightmare job. In our 60's house they installed the baseboards first then the wood flooring then we have baseboard heaters (forced hot water). Hopefully in WA you guys have forced hot air and they did the baseboard differently. I had to replace a baseboard last year and it was a nightmare just doing that. It was down a full inch to the sub-floor.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor

Member

It's actually not *that* bad, and the results are excellent.

For one, in a normal wall the studs act as heat bridges -- now they are covered with an extra layer of drywall and 1" - 1.5" of foam. It also blocks noise better than a regular wall; and lastly, the foam (at least the one I use) also acts as a vapor barrier.

Obviously, you do something like this only when the easier options are not available, or already exhausted. If you can fix it by blowing in some insulation, or removing the siding and redoing the insulation -- by all means, do that first because it's easier and quicker. In my case, this was the easiest option to beef up my insulation.
Critsmcgee
join:2011-12-02

Critsmcgee

Member

said by aurgathor:

It's actually not *that* bad, and the results are excellent.

For one, in a normal wall the studs act as heat bridges -- now they are covered with an extra layer of drywall and 1" - 1.5" of foam. It also blocks noise better than a regular wall; and lastly, the foam (at least the one I use) also acts as a vapor barrier.

Obviously, you do something like this only when the easier options are not available, or already exhausted. If you can fix it by blowing in some insulation, or removing the siding and redoing the insulation -- by all means, do that first because it's easier and quicker. In my case, this was the easiest option to beef up my insulation.

We did 2" commercial grade foam board behind the walls in the attic. The only downside is we can't get the left/right side of the house only the front/back.

aurgathor
join:2002-12-01
Lynnwood, WA

aurgathor

Member

I assume that was on the outside of the room, and in an un-occupied area that's a trivial job. But you can also put the foam on the inside, it just requires a bit (?) more labor, and long screws.

FYI, #6 drywall screws are available up to 3" in 1/4" increments, so with 2x 1/2" drywall, you can have 1.5" of foam sandwitched between 2 sheets of drywalls with #6 screws. Longer than 3" screws are only available in #8 or thicker sizes.

natedj
Elected
Premium Member
join:2001-06-06
Irmo, SC

natedj to aurgathor

Premium Member

to aurgathor
said by aurgathor:

What I do is put a 1" - 1.5" solid foam on the top of the drywall, and then another layer of drywall on top of the foam and then fasten them to the studs with long (2.5" - 3") drywall screws.

How to you handle the areas around doors and windows with this approach? Seems like it would be more work getting the existing wall vents and light switches to be flush with the new wall, not to mention taking a hit on the amount of usable square footage in the room
18189353 (banned)
join:2014-10-28

2 recommendations

18189353 (banned)

Member

said by natedj:

said by aurgathor:

What I do is put a 1" - 1.5" solid foam on the top of the drywall, and then another layer of drywall on top of the foam and then fasten them to the studs with long (2.5" - 3") drywall screws.

How to you handle the areas around doors and windows with this approach? Seems like it would be more work getting the existing wall vents and light switches to be flush with the new wall, not to mention taking a hit on the amount of usable square footage in the room

Yea the square footage loss is a MAJOR cost. GLA is like $100+ a square foot.