Long time reader first time post…
I have a cinder block foundation that has had several coats of paint.. its peeling and upon further review the parging is compromised from previous water issues.. freeze / thaw cycles.. all water issues have been addressed ie downspouts and grading . i have a small cape cod style home that has only 250sq ft of exposed foundation.. i would like to fasten metal lath to the block but am undecided about the fasteners. cultured stone will be applied at a later date.
Replies
thinset vs. lath
Unless you are using metal lath over a slip sheet type moisture barrier, then I think your better off not bonding with metal lath. It will eventually rust out (even if galvanized) and your holding power is limited by your fasteners in terms of tension back to your foundation wall.
I would recommend stipping the old parging with a hammer drill (chisel or bushing bit) and prepping your base with thinset. Use a quality nog sagging type thinset wtih a large notch trowel. Work a thin bed of thinset firmly into the surface with the flat side first and then smooth out your thick bond coat immediately on top of that. Run all your finish towel lines vertically (drainage channels for any possible bulk water penetration) and let set overnight. Your cultured stone mortar bed wiill knit into this bed coat with a consistent and tenacious bond.
If your dead set on lath, then I recommend shooting it on with powder actuated gun and metal washered pins or hand drive masonry cut nails through galvanized plaster washers. I'd still take as much of the failing parge coat off as possible either way.