Wall section suggestions -existing house
I was looking for some input.
What I have-
Tract house blt in 1973 suburbs of D.C. Split level. Current 2×4 wall section from inside out is drywall/r-11 (maybe 13) fiberglass/ 5/8″ plywood (board and batten 303 pattern) Thats it!
I need to replace the ext siding and trim. While Im at it Im going to upgrade windows and add insulation/airsealing.
This week my daughter noticed mold on the surface of the drywall in the corner of her room, and behind her desk- both had something tight up against the wall. Its been colder than usual here. She has a fish tank in her room along with the humidifier we run(on central Hot air system) . My guess is that the poor condition of the siding, and the lack of a air barrier to keep cold air from flowing through the wall cavity allows the drywall to become cold which in turn condenses moisture on the surface(found behind furniture where the inside air doesnt curculate)
I keep the temp around 68-70, and the humidifier around 30-35%
We get condensation on the single glazed aluminum windows, those without storms form ice on the interior.
In the summer the rear bedrooms are 30 degrees warmer than the fronts – rear faces south west.
My plan 1:
Replace the exisitng aluminum windows wih Anderson Casements.
Walls repaired working from exterior- remove existing siding, add layer of 1″ foil faced foam sheathing- run 18 inches above top plate-seams taped, strap with 5/8 (ripped from existing siding), install windows, side with new 5/8″ plywood siding- primed front and rear. Detail the exisitng outlets and switches with canned foam around the boxes, penetrations in drywall.
Attic – add blown in isulation and cont. ridge vent and soffit vents. seal holes in plates and around ceiling boxes
Basically a “rain screen” wall with the idea that the foil face will reduce some radiant heat on the rear of the house, hot air rises up and out through the attic. The foil faced foam would be taped and act as an air barrier, along with adding 6 to the r value of the wall. I would end up with a wall of around R-17, with fewer air leaks in or out, and much better insulated and constructed windows.
Plan 2
Remove siding, remove exisiting batt insulation.
Spray in foam to 3 1/2″ wall thickness. Sheath with 1/2″ foil faced and 5/8s strap , primed 5/8 siding (or just reapply siding over foam)
Reuse batt insulation in attic -with amount of wall space vs attic I shoud be able to do 2 + layers with the existing, so 7″ pls the existing 4 or 5″
Sorry about the length but judging from some of the other posts here I wanted some thoughts about either of these sections.
Thanks
Steve