I’ve had a number of clients recently who have removed their EIFS and changed the facades of their homes with other exterior finishes (traditional stucco, siding, etc.). However, I have one client who asked if he would notice a big difference in the utility bills after losing the R value of the rigid insulation removed with the EIFS system
My question to anyone who may have had similar projects. Has anyone considered to remove the EIFS, remove the exterior sheathing, remove the batts insulation (leaving the gypsum board finish intact). Then spray polyurethane insulation into the stud cavity space (at R=7/inch that’s better than R=13 with batts in the 2×4 stud space), nail back new sheathing, and do any other exterior finish. Anyone? Comments? Am I just tired and should I just go to sleep?
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OK, after a little sleep and some other online research, I think the solution to this type of question is to use Structural Insulated Panels (SIP). This will provide additional R value and a nailing surface for any siding.
I believe you're talking about a renovation. How's are you going to use SIPs when the wall (or other plane) is already in place?
Are you going to remove the wall structure completely?
Or is this more of an addition issue?
Actually, as I continued reading up on the SIPs I don't believe that's the answer. Now in looks to me like the SIP wall panels are always intended to be within the bearing line. That's not the solution I'm looking for.
I'm looking to keep the existing stud wall framing intact and doing something on the exterior to regain the R value lost by removing the EIFS. The existing stud framed wall still has batts within the cavities.
If you are removing the exterior to expose the cavities, plus you have only 2x4 studs for framing, then that should tell you the obvious. Pull out the FG (check your car service manual for how often you should replace an air filter) and have the cavities done with closed cell foam. What will the new exterior be in your case? You could always add an inch of rigid foam before the siding, but I gather there was some reason for removing what was there before.
The home owner wanted to remove the Dryvit finish and do a vertical groove wood siding finish instead. I'm not sure if he has already encountered mold problems or not. But in removing the Dryvit he is concerned about the expected increase in his utility bill by removing the added R value of the rigid insulation. He had no intention of messing with the drywall on the interior. My question was if there was something that can be done to increase the R value without messing with the drywall and stud framing. The initial thought I came up with were: a) remove the sheathing, spray foam insulation into the cavity with R=7/inch of thickness) and b) remove sheathing and nail or screw on SIP panels. But as I said, I now understand the SIP panels are not meant to be installed in that manner.