[jasonmschmidt]

Hello DIYers. This forum has been a godsend for my project and I appreciate all the advice every gives.

I'm trying to explore my options for redoing the insulation on my 1830's home. The walls are funky. Nothing is standard. They are between 4" and 6" deep in spots. All the drywall/plaster is being removed to expose the "studs". What's the best option for a price-sensitive DIYer for me? Unfaced fiberglass batts cut to size behind a vapor barrier? Mineral wool? Put up a barrier and blow in fiberglass/cellulose/mineral wool? I don't plan on being here for too many more years and I have very cheap heating costs so I don't think spray foam would be good investment.

I appreciate any advice you guys have!

 

[Nealtw]

Before you get into insulation, caulk all the cracks around the studs, no air leaks from below and add blocks where you should have bottom plate between the studs and then do the same at the top, no air movement.

 

[jasonmschmidt]

Before you get into insulation, caulk all the cracks around the studs, no air leaks from below and add blocks where you should have bottom plate between the studs and then do the same at the top, no air movement.

Good point. This is a balloon frame house and so the wall cavity extends through two stories. Do you recommend caulk or a great stuff gap filler-type application?

 

[Bud9051]

Ya the crunch method we see is terrible. With insulation, neatness counts, it reduces the number of miscellaneous air pockets which transfer more heat.

If you caulk as Neal described even fiberglass will do well.

In terms of keeping the cost down much of the existing FG could be removed and reused. Trimmed for a good fit with the facing overlapping the studs.

Where the cavities are deeper strip the thickness of the insulation for a tight fit. Where you need extra steel it from another, it comes apart in layers somewhat.

Of course all new insulation would be nice, I like Roxul, but at a cost.

As for a vapor barrier we don't see your location and in most locations no VB is needed. Far north and Canada still use them. Citation available.

Bud

 

[Nealtw]

Good point. This is a balloon frame house and so the wall cavity extends through two stories. Do you recommend caulk or a great stuff gap filler-type application?

Fire rated foam will burn so it is only to stop air, what ever you have handy that you think will stop the air. It should all be 30 minute burn thru.

 

[jasonmschmidt]

Ya the crunch method we see is terrible. With insulation, neatness counts, it reduces the number of miscellaneous air pockets which transfer more heat.

If you caulk as Neal described even fiberglass will do well.

In terms of keeping the cost down much of the existing FG could be removed and reused. Trimmed for a good fit with the facing overlapping the studs.

Where the cavities are deeper strip the thickness of the insulation for a tight fit. Where you need extra steel it from another, it comes apart in layers somewhat.

Of course all new insulation would be nice, I like Roxul, but at a cost.

As for a vapor barrier we don't see your location and in most locations no VB is needed. Far north and Canada still use them. Citation available.

Bud

Thanks for the advice. Yeah. The crunching is terrible. I am in Cleveland, Ohio. For the cavities that are...let's say 18" OC, how do you fill those areas? Do you just butt two batts together?

 

[Bud9051]

First, vapor barriers are funny. More recent science has said, if you air seal really well then the majority of moisture concerns goes away, and to the point that no vapor barrier is needed. But some is not a problem.

Also, if a VB is incomplete the missing area only reduces the effectiveness by that amount of area. So piecing insulation together with seams is just fine as long as the insulation itself is tight together and neat.

For cavities wider than the insulation you can cut strips and insert or cut lengths of the batts to go horizontally. If the cavity is 20 inches you can cut the facing at 23" and then trim the fg back an inch on each end. That makes the fg a tight fit and gives you a flap to staple. You could tape the seam but that would be more to hold the seam together but stapling the new flange will be good.

Also, I prefer caulking, I use the large tubes of PL 3x construction adhesive, less expensive in the long run.

Note, if compressing the fg a little is needed it doesn't hurt as often stated.

Bud

 

[Nealtw]

 

[user_12345a]

First, vapor barriers are funny. More recent science has said, if you air seal really well then the majority of moisture concerns goes away, and to the point that no vapor barrier is needed. But some is not a problem.

Plastic vapour barriers done right do a better job of air sealing than drywall and trim.

Gaps can form as the house shifts.

Can't really seal well to the electrical boxes.

 

[Nealtw]

Good point. This is a balloon frame house and so the wall cavity extends through two stories. Do you recommend caulk or a great stuff gap filler-type application?

What is your plan with the windows and outside work on siding?

Some of the framing looks dicey.

 

[jasonmschmidt]

What is your plan with the windows and outside work on siding?

Some of the framing looks dicey.

The framing is dicey lol. I've lived here for 2 years now. The siding is newer vinyl, on top of asphalt siding, on top of wood siding. I didn't do the work so . The house was originally one story and then they decided to cut the studs and raise the roof about 3 feet. Super wonky but it has held up for 100 years so I won't touch anything other than fixing a few framing issues.

 

[Nealtw]

The framing is dicey lol. I've lived here for 2 years now. The siding is newer vinyl, on top of asphalt siding, on top of wood siding. I didn't do the work so . The house was originally one story and then they decided to cut the studs and raise the roof about 3 feet. Super wonky but it has held up for 100 years so I won't touch anything other than fixing a few framing issues.

The shiplap on the outside must be heavy duty, they have used to the sister the studs. I like the way the staggered the joints, likely where the saw fit between the board.

So this is your house. :biggrin2:

 

[3onthetree]

I've only worked on houses as old as 1900, and yours being 70 years older and hacked up I can't imagine any straight or aligned wood anywhere. You may want to consider some sistering to give your drywall (which is not as forgiving as plaster) some smoothness with proper attachment. And can set up 16" o.c. while you are at it.

 

[Nealtw]

I've only worked on houses as old as 1900, and yours being 70 years older and hacked up I can't imagine any straight or aligned wood anywhere. You may want to consider some sistering to give your drywall (which is not as forgiving as plaster) some smoothness with proper attachment. And can set up 16" o.c. while you are at it.

I was thinking of a 1 1/2 inch wall about a 1/2" away with just a few blocks back to the old wall for stiffness, That would give him straight on layout and deeper insulation.

 

[APA]

The framing is dicey lol. I've lived here for 2 years now. The siding is newer vinyl, on top of asphalt siding, on top of wood siding. I didn't do the work so . The house was originally one story and then they decided to cut the studs and raise the roof about 3 feet. Super wonky but it has held up for 100 years so I won't touch anything other than fixing a few framing issues.

There you go. That house will probably be there for a 100 more. Don't get hung up on how imperfect it is unless there is termite damage or extensive rot or something is broken. Those rough lumber houses are a pain to work in, but they will be there for decades more...

 

[APA]

Plastic vapour barriers done right do a better job of air sealing than drywall and trim.

Gaps can form as the house shifts.

Can't really seal well to the electrical boxes.

That's the key. They are very easily done wrong.

 

[jasonmschmidt]

This house has definitely been a pain to work in. The drywall was auction pretty flat and looked good. I've gone back and forth on whether to shim, sister stud or build a small wall in from of the other to rehang the drywall. I think I'll be okay with just shimming again. The cavity would already be close to 6" deep so that should be good fro my insulation.


I appreciate the advice given. I feel more confident with just buying new fg 6" batts and installing them cleanly. Is there any advantage/disadvantage to buying unfaced insulation and just putting a vapor barrier over the entire wall? Seems slightly easier than cutting the facing to create a flange for some of the pieces that would need to go horizontal.

 

[Nealtw]

I think paper faced would be just hard to deal with as just drywall, holes around outlets and switches, gaps at floor, all places hard to get a good seal. Careful fitting insulation around outlets and jogs in the structure is always a pain, more so in your structure.

Something that stops air movement, sealing the outside wall or VB on the inside stop drafts going thru but holes in insulation will let cold thru to the inside surface anyway.

we go for perfection with the VB, the black crap is not available in the US, I understand Quad is used down there.

 

[Nealtw]

This the old way of doing boxes, they cut a hole in the sheet later and pull all this poly out and tape it all around . The plastic boxes makes it easier, they are used for things like cable or speaker wires too.