How to Insulate a Basement Header

Easy, do-it-yourself video for insulating the cavity header in your basement to save money on your energy bills using ROXUL ComfortBatt R22 in Canada and ComfortBatt R23 in the USA.

[confidentlocal]

In most climates where band joist insulation makes a noticeable difference you'll need a vapor retarder over any air-permeable insulation. The exception is if you do put enough sealed foam board into the cavity first that condensation never forms on the back face of the mineral wool. If you simply install the mineral wool like this and leave it, you'll have a wet rim joist in the winter. Ask me how I know!

[lightspeedguru]

After watching many youtube DIY videos you come to value the higher production quality and presenter skill in some over others. I've watched a couple of videos with this guy and I have to say, his presentation skills are fantastic. Great delivery of the material with confidence and a really smooth, natural presentation. The videos never mention his name but he has the charisma to pull off his own channel if he wanted one.

[VBYCHOICE]

I watched it twice! You saved me a ton in labor. I can do it myself!!

[magyart]

I used this and found it easy to work with and effective.

[PlumbDrumb]

I can confirm, those spots are the worst, especially on a bricked house with a sunken basement. It wasn't until we took off our old drywall and wood paneling that we saw much of those areas went up without insulation of any kind, and you could feel a direct draft coming through from the top of the brick wall, with cobwebs blowing in the wind and everything, lol.
Stuffing insulation in those spots made an immediate and drastic difference to the the temperature in the corresponding rooms (and the whole house, really). I probably should have squirted some foam in there first, but this actually did the trick - nothing gets through.

[revelations]

building science is saying that there should not be any vapor retarder over wool insulation. Can you please explain how using the plastic over the insulation is necessary in an area with high humidity?

[peterfrederick]

how are you adding a vapor barrier to the sill?

[torymountain]

Why not show how easy to then install the vapour barrier and tape up all sides? Job incomplete.

[Steve_Bonham]

There’s so much conflicting information on this topic. I’m currently in the process of insulating my basement rim joists. I’ve removed the old pink fiber glass which was folded over on itself&black. I’ve then used a shop vac to vaccum the debris within. Should I now just place rigid foam board in its place, bordering it with great stuff, or is this an option? Would I need this in front of the foam board as foam board is combustible?

[NeronFrancis]

Did you use a vapor barrier with the Rockwool insulation?

[anthonynickolas]

I was wondering if I could use 2 inch rgid foam in the boxes, seal the seams and then apply r14 roxul against the foam for added r-value. Would i need to apply a vapor barrier with this setup or would it cause moisture problems since the rigid foam is considered a vapor barrier as well? Any thoughts?

[steveblacktunes]

Do u need to cover it at this point? Or could u just leave it exposed as is?

[atarileaf]

Shouldn't a vapor barrier like tyvek be stapled to each header first?

[runningwolf]

his it possible for the air to escape at around the bat that you just put in the rim joists. i was wandering if foam or some kind of tape or silent should be put around the bat to prevent air from passing

[Welcome_To_Life]

I am creating a small dust controlled workshop in an unfinished area of my basement. I want to avoid putting in a drop ceiling. Should I cover exposed insulation with mill plastic? I am trying to separate this area from the other unfinished gaps at the tops of the walls of the finished parts of the basement.

[ROCKWOOLNorthAmerica]

Hello Susan,

Vapour control layers need to cover the entire area of the wall. In cases where your vapour control layer also acts as your air control layer, it would need to be very carefully detailed for continuity to ensure air leakage does not occur. If it is simply a vapour control layer in isolation, it will not need to be taped, but fitted to cover the area in question.

Ultimately, yes- you will need to insert a vapour control layer between the floor joists.

We hope this helps- ROXUL

[runningwolf]

I was wandering if it wold be better to use comfortboard to do the rim joists, then use rockwool insulation

[neckbont]

wouldn't it be also beneficial to caulk the corners prior to putting in the Roxul?

[frogmanpipes]

Do you need that vapor barrier? Using rockwool. I used 5/8 foil backed drywall. And was told I didn't need to hang the plastic sheeting.

[herptyderp]

Why is the vapor barrier on the inside? Wouldnt it be better to put it to the wall in the form of sprayfoam or hard board?