exterior substrate for mosaics

[cindy fisher]

Hi everyone,
I am a mosaic artist and would welcome suggestions on an upcoming project. I am trying to figure out the best means of attaching a 24' wide x 12' high mosaic mural to a brick wall. Said brick wall is the side of a building that is built on a river, so elaborate staging will be called for. Also, this is Massachusetts so freeze thaw is an issue. My first choice is to assemble the mosaic on panels that are then attached to the brick wall mechanically. For instance, if the panels are 4' x 4', they could be screwed into the brick wall but not actually butting up against each other, with just 1/8" gap or so between panels, the spaces worked into the design. I have installed many mosaics using the panel method where I use 1/4" hardibacker and leave mosaic tiles out on stud lines, then attach and cover up screw with mosaic tile. So my question is WHAT substrate to use. I found a great thread on this site from 2006 and did a lot of google searching for products like permabase, magnesiacore, versaroc, wedi etc etc. I guess part of my question is, has anything new come along in past 3 years that is a lightweight exterior substrate that works?!?!? Many thanks, Cindy ps my website is bigbangmosaics.com to see my work

[matman]

Hi Cindy

You're not to far from me. I took a look at your website, you've got some beautiful work there, really nice. If I'm ever up your way I'm gonna stop by if its possible.

You know more exterior board names than I do What don't you like about the boards you're using now, too heavy? What about Wedi, can't get much lighter than that. You can use that on vertical exterior in some cases (paraphrasing Wedi). Ring em up tell them what you got, see what they say.

[cindy fisher]

thanks for writing, Matt. I usually use hardibacker 1/4" but since it is not recommended for exterior use.....though I HAVE used it outside - I am hesitant to do so on such a large surface that I can't take any chances with. I haven't used any of boards I mentioned, just read of them online and wanted to get some expert advice from users of these products rather than just the manufacterers. But yes, I can call each and explain my project and learn more that way. and if you are ever near by, give me a call!

[Jim wood]

I would use WEDI, completely waterproof , lightweight and rigid.

[cx]

Welcome, Cindy.

I took the liberty of making you a hot link to your website. After a few more posts you'll be able to post urls yourownself. Little anti-spam measure we have in place. You might wanna make you a permanent signature line and add your website link there so it'll appear in each post.

I would not use the Hardi for that project for the reason you indicated; the manufacturer doesn't approve it.

But you could use any number of other CBUs or a foam board such as Wedi as Jim suggested.

I would recommend you contact the good folks at Laticrete and discuss your installation. They have excellent products for such applications, the one that springs to mind being 310, I believe. An epoxy formulation that would allow you to attach those panels without any mechanical fasteners and would provide some flexibility in making the installation flat on the wall. Talk with your local rep and see if maybe he won't come look at your wall and make a recommendation.

My opinion; worth price charged.

[cindy fisher]

thanks everyone, this all helps a lot....