What would be the drawback(s) from using cement backerboard for the substrate on a manufactured stone veneer , using portland and sand for mortar, instead of a standard scratchcoat with expanded metal lath? I understand that portland and sand is the best mortar. The veneer would be applied as basically a dry stack configuration ( very slight joints). This is an exterior, south facing wall, with a six-foot overhang in northern Illinois. Go Cubs 🙁
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Fine Homebuilding's editorial director has some fun news to share.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Even manufactured stone is moderately heavy so I like the substrate to offer some "bite" for the mortar. So, even if I use backer board for a substrate (and I have), I always nail on self-furring metal lath (nailed through the CBU to the framing, or even the sheathing if it's plywood and not OSB), trowel on a scratch coat and comb it.
I suppose backer board might be OK for a mf'd stone that was like a shale, but if you're doing a "drystack" appearance, like a ledgestone, you have to treat it almost like the real stuff....in fact, with that stuff, I sometimes even use some metal masonry straps at times, to hold it in place while the mortar sets, or if a particular piece has some excessive overhang.
Go Cardinals :-)
Edited 8/4/2006 4:19 pm by Notchman