To lath or not to lath... that is my question

[curtis73]

To catch you up to speed... Just installed a fireplace in my living room. The framing is all 2x3 with varying spacing based on logical spans, but no more than 13" spacing. It is all skinned with hardie backer. I bought stone veneer from a quarry that cuts real stone, so truly random. Nothing like choosing the most difficult way of doing my first masonry project, eh?

I am not a very experienced cement-y type person. Aside from laying tile, I haven't worked much with masonry. So my plan of attack was to watch all the youtube videos and tutorials and then get some tips from real masonry-type people.

In all of the tutorials where veneer goes over wood, lath/scratch coat was used. This makes sense, obviously, since you basically need to make a masonry surface where there wasn't one before. In the videos I watched where the veneer was going over backer board, about half claimed that you must use a lath/scratch, and the other half said it isn't necessary because you're going directly to a masonry substrate.

I'm trying to figure out if I need lath/scratch on my hardie backer before the veneer.

Here is a quick picture showing the fireplace.

 

[bud16415]

Like you I’m far from an expert but having given you some ideas on the floor framing I will tell you what I would do.



I would cover it all with expanded metal lath and give it some tooth to hang on to.

I have tore more down where it was done this way than I have put up and that experience tells me it doesn’t want to let go. When I have ripped down stuff applied to a flat surface it is much easier to remove.