Today we’re using Schluter’s KERDI-BAND to see if I can waterproof this drywall and prevent this from happening again. So let’s dive into the video. Again, this is a total experiment, but I think it might work. And I was getting some help from Schluter’s technical people. So I’m pretty stoked to do this experiment. Let’s do it. First thing’s first, what we’re going to do is cut any silicone that’s on top of the baseboard and the quarter round here.

So I’m just going to slice that. And this is just going to come right off, which is good. Now I’m going to use a razor scraper to cut off any existing silicone sealant that’s up against the tub surround. Now what I’m going to do is start right here and slice all the silicone that’s up against the tub the whole way down because this is where we’re having a water problem. So that’s what I’m going to do. Not really that hard. And I’m just going to cut across. Now there’s paper tape here. I’m going to remove all that paper tape. Again I’m going to run the razor scraper along the side of the tub. This is Schluter KERDI-BAND. This is waterproofing band that you usually use to waterproof the KERDI-BOARD.

But for today we’re going to use it to waterproof this section. So this is what KERDI-BAND looks like. It’s orange. This is 5” wide, and it’s waterproofing material. So I cut a piece of the KERDI-BAND, and what we’re going to do is just put it right over top of the drywall here using unmodified thinset. So you can see I just cut it down to size so it comes out to the edge of the drywall. We just want the thinset to be thick enough so it’ll stick to a trowel or stick to a putty knife. I just wanted to make sure that I got the right piece of KERDI-BAND before I start putting in the unmodified thinset. So I’m going to start at the top and work my way down with the thinset. This is a very, very tight space. Oh, and the other thing I wanted to point out to you is I could’ve taken out the drywall here and replace it with new drywall.

Or I could’ve repaired it with cement board and done this. But for right now, this is solid enough, so I’m just going to put thinset right over and embed the KERDI-BAND. So here you go. I’m just going to embed the KERDI-BAND. Now I’m just going to embed the KERDI-BAND into the thinset. And definitely squeeze out any excess thinset. That’s what you want to do. Definitely make sure you get all the thinset off the tub.

You don’t want this drying. For right now I’m going to clean up the excess thinset, let it dry, and then come back and put joint compound over it. But we’re going to let this set up and then come back. We’re on Day 2 now. The thinset has set up. And the KERDI-BAND is completely dry. So what we’re going to do for the next step is apply a thin coating of setting-type joint compound. Before you do that, though, just make sure that any loose thinset, you wipe it off the top of the KERDI-BAND and off the side of the tub if you have a tub surround like this one. The KERDI-BAND is pretty well-adhered to the latex paint and the part of the drywall that was damaged.

Yeah, it’s in good shape. In this case, I’m going to be using Easy Sand 20, so it should set up in about 20 to 30 minutes. Again this is setting-type joint compound. You don’t want to use pre-mixed joint compound. I’d mixed up the joint compound to have a consistency of a thick milkshake. It’ll stick to the putty knife here. I’m going to use my trusty 6” knife to embed the joint compound onto the KERDI-BAND. So I’m just going to go up and down the KERDI-BAND like so. Then what I’m going to do is take my knife and run it up the drywall just to smooth this out even more. We’re going to let that dry, come back, sand it, and then prime it. Now if your joint compound doesn’t look absolutely perfect, you can always put another coat on top of it. I want to stress that this is an experiment.

Knock down any high spots on your joint compound with your knife. Then you can sand it smooth using a sanding sponge, my favorite tool for sanding down joint compound. Then you want to apply Kilz 2 Latex primer to the joint compound. That’s super-duper important. I love using Purdy paint brushes. Once you get all the primer on, it dries, you can then apply your latex paint. Once this paint dries, I’m going to run a bead of silicone sealant between the drywall and the fiberglass tub surround to make sure that it’s waterproof at that junction. Ideally you would have waterproofing here already and then tile over. But I have a fiberglass surround in this case.

As found on Youtube