Mounting HardieBacker Around Fireplace
I am working to attach HardieBacker (non-combustible, right?) to a CMU wall that surrounds around our fireplace insert. The rest of the wall has drywall installed over 1x wood sleepers that are glued to the CMU. I want to install the HB on the same plane as the drywall and then mud, tape, and texture the whole wall so the HB portion is indistinguishable from the drywall portion.
I’ve cut some HB “strips” to create a non-combustible build up behind the HB panel, and now am faced with making it all stay in place against the wall. Screws? Okay, I can get those (but I don’t have a hammer drill to make the holes). Adhesive? Power Grab says no go on cement board. What would any of you recommend?
Thanks.
Replies
barsh
Why hardiboard?
Read the spec's closely on that insert-it's common practice to use drywall all the way up to most every insert I"ve seen.
For adhesives-can't beat PL Premium for sticking anything to anything. Being as it's a urethane-some expansion or pushing out by the adhesive might be a consideration. Brace off to keep the strips tight to the block.
or
rent a powder actuated device and shoot them on w/wo adhesive or adhesive and hand drive hardened concrete nails.
You could also veneer the strips to the block using thinset, then veneer the sheets to the strips in the same manner.
All these methods you should test and pick the best for your application.
Fastening Hardieboard
I chose HardieBacker because it was non-combustible (as opposed to drywall, which is the only other "option" I considered) and because it could be finished seamlessly with the surrounding drywall to become one flat wall around the fireplace. I did look at the insert manufacturer's specs for distance to combustibles and it said to maintain at least 4-1/2 inches either side and 35 inches up from the bottom of the firebox (as I seem to recall off the top of my head).
I'll take a look at the PL Premium as you suggest, but I am leary of expansion. I'm still considering using PowerGrab because I've already got some and because it just needs to be strong enough for long enough to hold what I've got in place so I can get some TapCons through to the CMU.
Thanks for your reply - it gave me options I hadn't considered and that were worth investigating.
Brash
Go to USG's website and take a look at their drywall Handbook .
it'll lead you through the high points .
As recommended by one responder to my post, the USG Drywall Handbook is a tremendous resource for these issues. It is available as a free download on the USG website. Thanks for recommending that.
Barsh
There's not much they don't cover nor miss.
There's not much they don't cover nor miss.
Well, I guess that covers it!