If you’re gearing up for a bathroom remodel, basement tile job, or even an outdoor patio wall project, you’ve probably stumbled on that exact question: can I slap waterproof wall tile backer board on a brick wall? As a supplier of this exact stuff, I get it—there’s so much conflicting info online, and brick walls come with their own quirks that make people nervous about messing up. Let me break this down straight, no fancy jargon, just real talk from someone who’s dealt with hundreds of contractors, DIYers, and remodelers over the years. Waterproof Wall Tile Backer Board
First off, let’s get one thing out of the way: yes, you absolutely can install waterproof wall tile backer board (let’s just call it WWTBB from here on out, I’m sick of typing the whole name) on a brick wall. But it’s not a “rip off the old brick and start fresh” job—you can’t just hang sheets over brick like you would drywall. Brick is porous, uneven, and sometimes has crumbly old mortar that’ll cause issues if you skip a few key steps. I see so many people cut corners here and wonder why their tile starts popping off a year later—trust me, I’ve replaced way too many botched jobs that skipped these prep steps.
Wait, first—let’s make sure we’re talking about the right kind of brick wall. There’s interior brick (like the accent wall in your dining room or a basement foundation brick wall) and exterior brick (like a patio wall or exterior house siding made of brick). Both work, but exterior brick needs a bit more care because it’s exposed to rain, snow, and temperature swings. That’s where WWTBB really shines—unlike regular cement backer board, it won’t absorb water if there’s a little leak or you spill water on it, which is huge for exterior or high-moisture interior spaces like showers.
Now, why would you want to do this in the first place? Let’s be real: brick is pretty, but it’s not the best surface for tile. It’s uneven—those little mortar lines and rough brick faces mean you’d have to use way more thin-set mortar to get a smooth tile surface, and that extra mortar can crack over time. Also, old brick walls (especially basement ones) can have efflorescence—those white powdery spots that come from mineral salts leaching out of the brick. If you tile over that, it’ll stick for a minute, then the efflorescence will push the tile right off. WWTBB acts as a smooth, consistent barrier between the rough brick and your tile, plus it’s waterproof, so it seals out any moisture that might get through the brick, which prevents mold and mildew too. That’s a win-win in my book.
But here’s the catch: you can’t just screw WWTBB straight to a brick wall. Brick is hard, and the surface isn’t flat, so you’ll need to build a little gap between the brick and the backer board. That gap is non-negotiable—trust me. Why? For air circulation. If you have a solid contact between brick and backer board, moisture that gets trapped behind the backer board can’t escape, and that leads to rot, mold, and even the backer board itself breaking down. The gap is usually about 1/4 inch, and you make that with something called furring strips. Furring strips are thin, wooden or metal strips that you screw to the brick wall, and then the backer board screws into the furring strips. That creates the perfect little air gap.
Wait, what kind of furring strips? I’d recommend metal furring strips every time. Wood can absorb moisture, warp, and even grow mold if the gap is tight, but metal is waterproof and won’t rot. It’s a tiny extra cost, but it saves you from a huge headache later. You’ll want to space the furring strips 16 inches on center, same as you’d frame a wall—so they line up with the edges and the middle of each backer board sheet. That way, every screw you put in the backer board has something solid to bite into.
Now, the prep work for the brick wall itself—this is where most people mess up, so pay attention. First, you need to clean the brick. If there’s dirt, dust, paint, or that efflorescence I mentioned earlier, you have to get rid of it. How? For efflorescence, a mild acid wash (just follow the instructions, don’t go too strong) works, or a stiff bristle brush with water and a little vinegar for smaller spots. For general dirt, a pressure washer on low setting (don’t blast the brick too hard, you can chip it) or a regular scrub brush and trisodium phosphate (TSP) will do the trick. Let it dry completely—like, 24 hours minimum. If you put furring strips on wet brick, moisture will get trapped behind the strips and cause problems.
Next, fill any big gaps or holes in the brick. If there’s a crack in the brick or a missing chunk of mortar, use a concrete patching compound to smooth it out. You don’t have to get it perfect, but you want the furring strips to lay flat so the backer board is even. Pro tip: don’t apply any adhesive directly to the brick before installing furring strips—wait until the furring is up.
Once your furring strips are up and the brick is prepped, it’s time to install the WWTBB itself. Let’s talk about the screws here: you need special backer board screws, not regular drywall screws. Backer board screws have a sharper point and a deeper thread that bites into both the backer board and the furring strip without stripping. Space the screws 8 inches apart along the edges and 12 inches apart in the field (the middle of the sheet). And don’t overdrive them—sink them just enough so the head is slightly below the surface of the backer board, not deep enough to crack the board. If you’re working in a shower, make sure you leave a 1/8 inch gap between backer board sheets, same as you would with tile, so you can fill those gaps with waterproof grout later.
Wait, what about if your brick wall is in a shower? Can you use WWTBB there too? Hell yeah, that’s one of the most common uses for this. But you’ll want to add a waterproof membrane over the seams after you tape and mud them. Wait—seams: WWTBB has seams just like regular backer board, so you need to finish them properly. Use fiberglass mesh tape made for backer board, and a thin-set mortar (not regular grout) to embed the tape, then smooth it out. Once that’s dry, you can apply a waterproof membrane over the whole wall if you want extra protection, especially for showers. That step is optional but highly recommended for high-moisture areas.
Now, let’s get into the common mistakes I see people make, because these are the ones that turn a simple project into a disaster. First, skipping the furring strips. I can’t tell you how many DIYers I’ve talked to who tried to glue WWTBB straight to brick with construction adhesive. It sounds easy, but over time, the brick will move a little with temperature changes, the adhesive will fail, and the backer board will start to bubble and separate from the wall. The air gap isn’t just a random step—it’s there to accommodate that tiny movement and keep moisture away. Second, using the wrong screws. Regular drywall screws will snap or strip in metal furring or hard brick, so don’t cut corners here. Third, not letting the brick dry all the way. I once had a guy call me panicking because his WWTBB was growing mold behind it a month after installation, and when we went to look, he’d installed it right after a rainstorm and skipped washing the efflorescence. Lesson learned.
What about if your brick wall has lead paint or asbestos? Wait, that’s a whole other thing—if your home was built before 1978, there might be lead paint on the brick, and before you sand or pressure wash it, you need to test for that. Same with asbestos in old mortar joints. If you find either of those, don’t try to handle it yourself—call a professional. It’s not worth the health risk, and you can still install WWTBB over brick, you just need an expert to handle the prep.
Now, is there any scenario where you shouldn’t install WWTBB over brick? Let’s see. If the brick wall is super unstable—like, if whole bricks are loose or falling out—you probably need to repair the brick first before adding backer board. Or if you’re tiling a full brick wall in a really high-traffic outdoor area, like a pool deck wall, you might want to add an extra layer of waterproof membrane, but that’s not a dealbreaker. For 90% of projects, brick wall + WWTBB is a totally solid combo.
Wait, let’s talk about why our WWTBB is different from other backer boards, just so you know what you’re getting. A lot of backer boards out there are just cement, which will absorb water over time if it’s not sealed. Our WWTBB is made with a special core that’s 100% waterproof, no sealing needed for most projects. That means if you spill water on it, or it gets splashed, it won’t hold onto moisture. It’s also lightweight, which makes it way easier to carry and hang than heavy cement backer boards—great for DIYers who don’t have a whole team helping them lift 50-pound sheets. It’s also mold and mildew resistant, so even in basements or bathrooms, you don’t have to worry about that icky stuff growing behind your tile.
Let me walk through a quick example to make this real. A customer of mine last year named Mike was remodeling his basement bathroom, which had a old, crumbly brick foundation wall. He tried to tile over the brick directly, used way too much thin-set, and within 6 months, half the tile fell off. He called me, and we walked through the steps: first, we pressure washed the brick to get rid of years of dust and efflorescence, let it dry for 48 hours, hung metal furring strips 16 inches on center, installed our WWTBB with backer board screws, taped and mudded the seams, added a waterproof membrane, and tiled over that. He texted me a month ago saying it looks perfect, no issues at all. That’s exactly why we love this combo.
Another example: Sarah, a homeowner in Chicago, was tiling her back patio wall made of red brick. Chicago’s winters are brutal—freeze-thaw cycles that mess up so many materials. She used our WWTBB, and she said it’s been 2 years, no cracking, no tile popping. The waterproof core is perfect for the snow and rain that hits that wall all winter.
Now, let’s answer some quick follow-up questions I get all the time. Can I use regular cement backer board instead of waterproof? Yeah, but you have to seal it, which adds an extra step. Our WWTBB is pre-sealed, so it’s faster and less work. How thick should the WWTBB be? For most wall applications, 1/2 inch is perfect. If you’re tiling a shower floor, you might go 5/8 inch, but walls are 1/2 inch. Do I need to use thin-set to attach WWTBB to furring strips? Yep, a small amount of thin-set between the backer board and furring strips helps create a tight, solid bond, but the screws are the main hold. That’s another thing people skip—just screwing the board to furring, no thin-set. That can lead to gaps, so a little thin-set goes a long way.
Okay, so let’s wrap this up. The short answer is: installing waterproof wall tile backer board on a brick wall is not only possible, it’s one of the best moves you can make for a long-lasting, tile job. You just have to do the prep right—clean the brick, let it dry, add furring strips for air gap, use the right screws, and finish the seams properly. Skip the shortcuts, and you’ll have a tile job that looks good for decades.
If you’re gearing up for this project and need the right WWTBB, want to ask about thickness, pricing, or even tips specific to your brick wall (interior, exterior, shower, whatever), hit us up. We’re here to help, not just sell boards. No pressure, just honest advice for your tiling project.
Waterproof Backer Board REFERENCES
- Tile Council of North America. (2020). Tile Installation Handbook: Interior and Exterior.
- American National Standards Institute. (2018). A108.11: Specification for the Installation of Ceramic Tile.
- Portland Cement Association. (2019). Waterproof Wall Systems for Residential and Commercial Applications.
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