Let’s play “Myth Busters.”Everyone knows that it is important to keep the connections between tubs and its shower surround well caulked.I often find these areas recently caulked in an attempt to “spiff things up” for the sale.Take a look at this first picture. The gaps are 1/8" as you can see they are filled with 100% silicone. Don’t Seal the Gap Between Basement Wall and Floor to Keep Out Water. This is a full walk in shower 33x60. After the Durock panels are in place, you must fill the joints before you can install the tile. Cement ? Cement backerboards include Hardiebacker, Durock, Fiberboard, wonderboard, and similar products. Hey, just installed cement board (plastic barrier underneath) and applied mesh tape and thin set to seams. No Thinset underneath the backer board ... with both an epoxy grout and industrial silicone rubberized caulk to match the grout. I plan to use mesh and thinset over the seems also. This article describes repair procedures for cosmetic or functional siding issues that may arise such as loose siding, wind-damaged siding, siding paint or coating failures, and siding gaps, especially gaps at fiber cement siding butt joints where lap siding is installed. I will apply mesh then thinset. Why would you want the water to go through all the layers and get trapped behind the wall? If you decide to use screws, make sure you keep the screw heads flush with the cement board surface. If it's possible to remove and re-attach the foam board, I would suggest either a foam-compatible adhesive caulk or low-expansion spray foam applied to each joint, particularly the non T&G butt joints. Add Cement Board Tape to All Seams. Thinset Decoded: Which Thinset to use | Infographic, Self-Leveling Underlayment: The Ultimate Guide. Next, install the cement board paying attention to the fastening schedule, and keeping the bottom at least a half inch off the tub deck to prevent wicking. It may sound like a daunting task, but learning how to install cement board on a floor is possible even if you don’t have years of DIY experience. x 5-ft. and 3 x 5-ft. sheets of cement board are … When tiling with a cementitious-based tile adhesive, prime the face of the board with one coat of BAL Primer – diluted 1:1 by volume of water. Ensure to keep fixings between 15mm from board edges and 50mm from board corners. I want it waterproof hydrolic cement ?Any help With this I would really appreciate.I'am an electrician not a wall trade and i want it to be right , from … The manufacturers of the cement boards really want you to tape the joints in similar fashion to taping drywall. Cement board is water and mold resistant. JavaScript is disabled. This article series includes field reports of fiber cement board lap siding butt joint gap problems, fiber cement moisture problems, and other fiber cement lap siding installation or in-service defects, their diagnosis & repair. I’ve read where a lot of people fill the gap between the backer board and tub flanage with silicone and some people fill this area with thinset. Hardiebacker cement floor board is backboard used as an ideal substrate for vinyl, natural stone and ceramic tiles. plaster ? Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Using two layers of 1" foam board, with staggered and sealed joints is an even better way of guaranteeing a good air barrier. Thanks for the reply. Cement board comes in … ANSI standard A108.11 states to use alkali-resistant tape over the seams and then fill with thinset. Helping You to Do It Yourself! These materials bridge the gap between expense and effectiveness. Fiber cement board lap siding repair guide. Thanks. silicone is not the best sealant for porous materials better off with a urethane. One of the most common places to find water in a residential basement is in a puddle right next to the wall. A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Cement board. For a better experience, please enable JavaScript in your browser before proceeding. The mortar set in like a rock onto the cement board but all the ceramic came up with little to no mortar adhesion. Installing cement board at the beginning of your remodeling project is crucial when you want waterproof tile floors that will last for many years without cracking or other signs of damage. This is another blog post by Charles Buell, a Seattle, WA, Home Inspector. I'm including a photo. Pack in thinset, lay on the tape, and flat-knife to get it set in. I don't understand why you chose to leave gaps filled with silicone. This would be true for all seams except to the floor, shower pan or tub deck. Finally, you'll need an 8 x 12-ft. piece of 4-mil plastic sheeting and some straight 2x4s. 2 | Determine layout of HardieBacker cement board • Stagger all HardieBacker cement board joints. If you are going to tile over the cement board, you should tape the seams. I really don"t want to remove the silicone unless an expert says this will lead to a disaster. Installing cement backerboard is one of the more popular choices for a shower wall substrate. Is this overkill and is this a good process? Manufacturers' Caulk and Sealant Recommendation Sheet S-100B Issued July 2000 APPLICATION: General: James Hardie believes it is good building practice to seal the joints to prevent moisture, such as wind-driven rain and snow, from penetrating the wall cavity. The even plane seams should be addressed with alkali-resistant tape and thinset, no gaps. • Keep sheet edges 1/8 in back from walls and cabinet bases. Cement board is a type of backer board that is installed under ceramic tile. Like all the other caulks, this Silicone Sealant Architectural Grade caulk requires a caulk gun for application. https://www.diytileguy.com/self-leveling-underlayment/, 5 Ways to Screw Up your Cement Board Installation on Floors. We include diagnostic inspection photos and text explain how to recognize, diagnose, and cure this problem. Our page top photo shows loose and improperly installed fiber cement … I recently installed hardibacker board in a walk in shower. Cement board is readily available and relatively inexpensive (about $10 for a 3 x 5-ft. sheet). It has the dimensions of 2 x 2 x 11.25 inches and a total item weight of 1-pound. Cement board seams require mesh tape and thinset 1. The thin-set is a cement-based powder that you mix with water or latex additive to form a thick paste, which is used to seal the seams in the board and can also be used to set the tile. Grout and tile board are not water proof. GE Silicone II* Concrete & Masonry 100% Silicone THREE-HOUR RAIN-READY - Caulk has to have enough time to build adhesion to the surface and cure or dry adequately so it won't wash away when exposed to water. after drying and smoothing, I plan to coat with RedGuard. Is Hardibacker and Durock cement board waterproof? hellow I gutted my bathroom all the wall board and I put up cement backerboard and want to know what I can use on the seams I have the fiberglass mesh tape , Joint compound is for wall board grout is for tile . Cement board is the cheapest backer board for showers. So I installed the cement board flush with the lip of the tub because that’s how the framing was…ie> I couldn’t have overlapped the tub lip. This should not be that difficult. Sep 30, 2015 • By Matthew Stock. ... Let dry at least 5 days. When cured, it … • We recommend an 1/8 in gap between board edges. Versapanel cement bonded particle board is an innovative building material especially designed to meet the set requirements in regard to moisture tolerance and fire resistance, durability, safety and flexibility. Do not align with subfloor joints. DAP® Silicone Plus™ Premium Silicone Rubber Concrete and Masonry Sealant is a low-odor formula that creates a flexible, watertight, weatherproof seal for filling and sealing cracks and gaps in a variety of building materials. Leaving 1/8" gap between, then filled with waterproof silicone. Make sure to use a plastic sealing tape on the seams. Leaving 1/8" gap between, then filled with waterproof silicone. I had a contractor who installed a ceramic floor on a cement board, did not tape the seams and did not use thinset on the seams. I don't understand why you chose to leave gaps filled with silicone. In the corners, use a corner knife. Log in. The 30-in. I've never used it in any bath/kitchen remodel I've done and have never had a call back in years. Durock, a name brand cement board manufactured by USG Corporation and sold throughout the United States, is suitable as a backer board for tile. VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. Chemical caulk removers can cause damage to the surrounding tile and countertop surfaces. I've used clear packing tape and have had no problems of leakage ever since we reconstructed the bathrooms. Cement board, available in 4-foot by 8-foot panels, is standard for use as a tile backer board. The gap between the tile and shower pan will be caulked. – user36043 Apr 27 '15 at 15:17 @treeNinja I'm pretty sure you can do without that second layer of plywood. ... Seams. When installed properly they will give you many, many years of durable shower construction. Silicone represents another popular material to use as a concrete caulk. The last few posts about this bathroom remodeling project discussed hanging cement board to the bathtub wood studs. Enjoy _____ PFR Pressure busts pipes. I thought maybe the tape and redgard coupled together could fill the gap. Use silicone based grout sealer on all surfaces, especially on the inner curb to shower floor. I never allow the cement board to rest on top of a bathtub edge. It is used in areas of the house with high moisture and helps protect the sheathing from water damage. Hi Angus242. It does not degrade as fast as the organic urethane caulks, and it remains flexible yet sturdy in its hold. Alkaline-resistant tape should be placed over the joints and then feather the tile adhesive to leave a 150mm wide joint. Only need the Red Guard on the surface of the cement board. Honestly, there should not be a gap at all. My dilemma is that the gap is too big in some areas (1/4”). Also, the product comes in a pack of 12, while each cartridge contains 300ml. I install the tape with the thin set then waterproof everything. The gaps are between the sheets of backerboard where they meet, also where the board meets the shower pan. The seams are the most likely place it's going to leak why not waterproof them? • Never allow all four corners of boards to meet at one point. Cement board is the most common and widely-known backer board. One of the best uses for silicone caulk involves filling the gaps between concrete and other materials, such as brick, wood or metal. Learn how to easily remove silicone caulk with our video. This gap is then filled with pure silicone caulk before the ceramic tile is installed. Hardibacker installation instructions say to follow ANSI A108.11. Most cement board manufacturers will permit you to use nails or screws to attach the material to framing. The thinset and mesh tape are to strengthen the seams. We also like Wedi and KERDI-BOARD because they’re faster to install. Your email address will not be published. Tape the seams to prevent tile pops and feather the mesh tape with a wide layer of thin set being careful not to create a hump. The Red Devil Silicone Sealant comprises 100% pure silicone. When installing the cement backer board, I like to leave a 1/8-inch gap between pieces. If it isn't too late I'd remove the silicone and properly fill/pack the joint with thinset and of course mesh tape the seam. That means if rain is in the forecast, homeowners and pros typically will have to delay or cancel a project when using most caulks. Use thinset under the cement board and in the seams with tape.