Opinions on studding basement wall that's already insulated?

[crabjoe]

Last night, I got this bright idea that I want to finish off my basement.

Normally, I would have studded the exterior walls and added insulation, but my basement has this wall insulation that was put on by the builder.

With that in mind, and me like large rooms, what the best option to minimize the loss of space? Should I remove the existing insulation, so I can put the studs right against the wall, put the stud again the wall on top of the insulation then cut the insulation so it's puffy, take a hit on the space and move the studs out a couple inches, or is there another option?

Thanks!

 

[CNGsaves]

Depends on how "DRY" your basement is . . . regarding seeping water intrusion, condensation, etc.

Prior house I had was very dry and we finished with 2x4 studs on edge and used styrofoam in between the studs, with sheetrock over that. This required shallow electrical boxes and be very well-planned on your wiring as no extra room at all in boxes. Basement was very comfortable with this treatment (however mild midwest climate)

For "WET" basement situations with condensation or actual water seepage, you very well would want the gap from concrete wall to the stud (actually should use steel studs), and attach vapor barrier/plastic that run the moisture down to drainage system in the gap.

 

[Bondo]

Normally, I would have studded the exterior walls and added insulation, but my basement has this wall insulation that was put on by the builder.

Ayuh,.... What sorta insulation is there now,..??

Foam,..??
Fiberglass,..??

 

[crabjoe]

It's blanket insulation...

Looks like this...

As for moister, I'm not sure... I've never had any mold issues or damp areas.. And when my water heater went, it dried out pretty quick.. I've got a psychrometer around here somewhere, assuming I can find it, what would be considered dry?

 

[garrett1812]

I had a builder tell me people frame out in front of that type insulation. Doesn't help with space, but a nice feature is you can add extra insulation.

For maximum space you would want to insulate the outside of the walls. Way too much work now.

You could take it down and replace. If you do consider spray foam. All depends how much the square footage is worth to you.

 

[larry4406]

I build homes in VA and MD. When we finish basements we do what CNGSaves says - stud out walls and hold the back of the stud 1" off the concrete wall. Fire stop properly at top and then use Kraft faced R13 insulation.

You have what is known as FSK or flame spread insulation. Rolled blanket product for unfinished spaces. I believe it is less than R13 but may be wrong.

As you pointed out, studding in front of it you will loose space. Don't compress it with studs to increase room size as you will lessen the R-value.

If we have homes that we later finish the basement, we tear off the blanket product and start fresh.

 

[crabjoe]

If we have homes that we later finish the basement, we tear off the blanket product and start fresh.

That's what I was afraid of.... What about leaving it up, compressing the blanket and just adding more insulation? That way, I won't need to worry about hauling all whats there to the dump.

Thanks!

 

[North Run Grader]

Any future water intrusion the compressed insulation becomes a wick, then all of your new insulation is wet also. If you want maximum square footage, and maximum insulation strip all of that FSK, line the walls with 1" rigid insulation, tech tape all the joints, and spray foam all intrusions and the joist spaces. Build your furring wall up against the rigid, and insulate with Roxul or equivalent stone wool. Or build the furring wall 1" inside the concrete remembering to have a gasket under your sill plate, then spray foam everything that will be covered by your walls. If your budget is unlimited research Bluewood, Pinkwood, and Roxul Safe and Sound, and wall tite by Basf. Spend your time and money on the outside walls once, the rest is easy to replace.

 

[Casey69]

no way i'd use those hanging bats behind my studwall; talk about moisture sponges.

tear that stuff out & use rigid foam insulation glued to the wall & a studwall in front of it.

you're also not supposed to use vapor barriers in basements.

 

[crabjoe]

Are you guys saying I should do this?