Getting close to pulling the trigger. But need some help/confirmation
Again thank you to all who contribute to this site. Thank you!
I’m really close to ripping off the siding.
My question for you is ..
Will 3-3.5″ (recycled) XPS “roofmate ” be ok for my exterior insulation. Does the fact it’s “roofmate” change anything?
This product seems to be more ready available in my area. However I may have a lead on some ISO same thickness- fiber faced I think.
Zone 6-6a Canada (Barrie) to be exact
Wall construction from out side in.
1/2″ fiber board
(Was contemplating adding min 3/8 plywood on top of this so that I would have a sufficient nailing area to help secure XPS in-between studs. Could also tape the seams)
2×4 with R10 Kraft faced
All voids in the cavity have been sealed prior to reinstalling insulation
No vapor barrier – except ceilings
Air sealed drywall
Primer with 2 coats of latex paint.
After exterior insulation has been installed,
Install tyvek and all necessary flashings.
Install strapping
And finally siding.
Any pit falls seen here?
Widows have already been bucked out.
Thanks to everyone
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Replies
fixd,
Was in Barrie for the first time last summer visiting inlaws.
You plan sounds good. Either foam board will work.
Hey Malcolm
We're not on the map yet, but we're at the point we can start trying on big boy pants😉
Hit me up next time your up, would be a pleasure to meet you
So got some info on the ISO. It's "fiber reinforced cellulosic felt" faced.
3" =R17.4 and 31/2 =20.5
Would spray foaming the joints together suffice, or do I need to tape it.
If tape any idea what type.
Thanks to everyone for their in put!!!
fixd,
I'd tape the foam.
https://www.greenbuildingadvisor.com/question/tape-for-rigid-foam-seams
Sorry to bug you again
What would you say if I were to put 2 1/2" ISO R14.4 and then apply 1" EPS and apply an acrylic finish (EIFS)
would this hamper any performance ie drying or possibly adding a vapor barrier in the wrong place.?
Or keep the 3 1/2 and apply the EIFS omitting the EPS.
I'll have to reach out to the ISO company, maybe with it being fiber faced I could apply directly to it. Thoughts
I guess I would then put the rain screen before the ISO applying it the sheathing.... Would this system work?
I would not bother taping the foam but focus on the CDX over the fiberboard. Make that your main air barrier, this means tape the seams on it and seal to the foundation and your wall top plates. You can than fill any larger gaps between foam sheets with canned foam but I would not bother with the rest.
EIFS folks will probably want a substrate they can shape, so you will need a layer of EPS over the roofing foam. I would talk to the EIFS installer about this.
Most EIFS details have the WRB at the sheathing, so make sure you figure out those details beforehand. A crinkly housewrap might be a good idea in that case.
Akos
So right about shaping the foam. Forgot about that. Thanks
Ok would this work.
1" EPS
Crinkle wrap
2 1/2 ISO
3/8 sheathing taped and sealed
Fiber board
2x4
R10
Air sealed drywall
Maybe even put the 3/8 infront of the ISO tape it, then crinkle wrap and then EIFS ...?
I think the CDX over the iso makes the most sense in this case. This gives the EIFS installers a substrate they are used to working with and they can take it from there. Some EIFS systems require their own fluid applied WRB, I would talk to your installer before going much further.
Make sure you still tie in the CDX to your foundation and to your ceiling air barrier somehow for air barrier continuity. The foundation is easier as you can use a wider piece of tape to bridge over the foam to the concrete. You can than install a piece of ripped PT lumber over the tape to protect it plus the rigid from critters. The ceiling is a bit harder, maybe bead of caulk at the top of each layer could work.
If you chouse EIFS be sure you understand your system and that every detail must be perfect or it will allow water inside that could become huge problem. Note you will need to check for cracks and caulk any gaps regular.
https://buildingscience.com/documents/digests/bsd-146-eifs-problems-and-solutions
https://www.elitehomeexteriorsnw.com/eifs-siding-replacement/
Walta
So I've got alot going on in my head right now.
Couple more questions.
First off though, I think ISO first and then sheathing then EIFS is looking like the better choice.
Here are my questions
Does anybody see any disadvantage with the EIFS, as far as the finish being such a thick acrylic. Ie vapor tight etc
If you fell there are no issues there - should the fluid applied WRB be permeable or impermeable
Walta thanks for looking out for me.
Ok I'll leave it you and see what you say
Thank again!!
Want to also confirm:
If I can't get the 3 or 3.5 ISO,I might still be able to get 2.5 ISO R14.4.
Currently having R10 in the cavity will R14.4 still get me code compliant
And again irregardless of siding type - should the air barrier be permeable or impermeable
Thanks
Basically it doesn't matter. You have more than enough foam for condensation control so nowhere in the assembly will see enough moisture to matter. Generally it is almost always best to select permeable envelope elements though.
The one issue could be bulk water, this is why my earlier recommendation of a crinkly house wrap. This allows for a bit of drying through diffusion, not much but better than nothing. You can get similar effect if the EIFS installer does trowel on adhesive for the EPS with vertical grooves. There are also EIFS specific EPS that comes either grooved or with pucks to allow some extra drying.
Thanks Akos
So I have an update
I can get 4x8x 2.5" R14.4
Or 4x4x 3.5" R2o.5
1. Are you saying the r14 plus the 1" eps r5 will work Just fine
(What's the bare min)?
2. Any real benefit to use the 3.5 R20.5 (plus the 1"eps)
It has been 15_18 yrs, but I was involved in the dryvit lawsuit, I was involved with making the repair process that was to be used nation wide in order to obtain a warranty, this helped to keep homes insured and able to be put back on the market.
I know I've forgotten i few steps in taking with you all, but I've been more focused on the continuous insulation stuff.
I know I'll be able to flash and water manage the envelope.
So if you think going thinner will be a good wall, I don't mind saving a few bucks and not making the house any fatter than need be.
Thanks everyone for your
knowledge and input.
I need to order this stuff soon or it will be gone.
You are about zone 6 so from a moisture perspective, with R10 batts you only need about R6.5 of rigid. With either option you are well above that. If you are trying to bring it up to current code the R14+R5 will get you well above it. That is a pretty high R value wall, so not sure it is worth spending more on the rigid unless the price delta is pretty small.
The Dryvit stuff failed because of lack of wrb and flashing, sounds like you have that handled so I think you are on the right track. There is a newbuild with eifs around me, they did install a roll on WRB but none of the windows were flashed. Some installers just never learn.
Akos
Ok thank you, I think I'll go iso 14 + eps 5. Easy peasy.
Some of the things I've seen, it's amazing how much damage framing can endure before failing. Little drips of water and then more then you have a sponge all warm and cozy behind the foam. Mmmmm
Happened with hard coat too.