I’ve furred out my bathroom walls with horizontal pine 1×3 furring strips to make the wall flat (and allow some insulative thermal breaks). I plan to tile the tub surround with 6×6 porcelain tiles. Although I’ll be using Kerdi, I plan to put in CBU at least in the showering area as a backup in case something leaks.
My question is, will these furring strips be sufficient to hold up this surface, particularly the porcelain tiles? I’ve spaced the strips at 16oc, they are held up with #10 McFeely screws and SS screws closer to the tub. Screws are 16oc (at the intersection with the studs). So I’m not worried about the shear strength of the screws, it’s the furring strips themselves I’m concerned about. I know things fail; part of the reason the original bathroom failed was that the 2×4 ledger board for the old tub disintegrated.
Is there any point in e.g. doubling up the furring strips in the tub surround area? Getting the surface flat was a PITA with all kinds of shimming, but if I just double up I can use the same shimming schedule.
I won’t be hanging anything else on the walls, there’s plenty of blocking for everything else.
Replies
You'll be fine. Screw through the CBU into the studs as much as possible and the furring strip question is moot.
Sounds fine.
FWIW, I have been so disenchanted with the quality of the 1x3's I've seen lately, that I have switched to ripping my own from BC plywood (straighter, more stable, hold screws better, etc.) The material cost is about the same and the time spent ripping is made up quickly by not having to cull out 1/2 the stuff and no dealing with problems later.
Thanks, I'm usually good part of an hour at the lumber yard picking out just a few sticks that are plausibly straight. Have to watch those knots when screwing the DW. Next project I'll try steel framing...