A.Sean Gerolimatos, technical services manager for Schluter Systems, responds: With a few exceptions, unmodified thinset mortar is required for setting ceramic and stone tile over Kerdi membranes (800/472-4588, www.schluter.com ), as well as for bonding overlapped seams and connections to Kerdi drains. They can be installed on any type of support and can even be used to create partitions, with no structural support required. Whether or not you need a Kerdi membrane is a factor of use. It's still applied to cement board. @JimmyFix-it - hardiboard is not really porous unless it is completely saturated. More waste, yes, but I think you have to have a LOT of practice to hang those huge sheets like mongo does. Since the existing wall board will be removed, I'd prefer to go a little extra and install a water proof cement board type base so the tile has a solid substrate even if it were to get wet, such as from a plumbing leak, or from infiltration on an exterior wall (as unlikely as that might be). You are wise to use a cement board. But that doesn't address your question, so it's just a comment, not an answer as such. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? About an argument in Famine, Affluence and Morality, Acidity of alcohols and basicity of amines. With that said, lets take a look at the importance of choosing the right tile substrate, the options you have, and which tile underlayment material you should choose Kerdi Board or cement board? You don't want to block off the end of the air chanel and trap half a sheet worth of air under there.-Not paying attention to the direction of my knife. You provide the pitch during the tile set. This allows for future compression and an area at the corner where things are more forgiving. And for a more secure fit, you can also use screws. Also - use a good thinset. By: Author Olin Wade (Remodel or Move Stuff). I have corrugated metal shower surround & grab bars. Overall, waterproofing behind and around shower tile is a critical part of any installation to ensure that the area is adequately protected from water and moisture damage. Kerdi Board is suitable for a number of interior applications. Calculating probabilities from d6 dice pool (Degenesis rules for botches and triggers). Here are the fundamentals of tile installation over cement board. If you are laying tile on floors that are wavy or out of level, self-leveling underlayment is a great solution. This is a bit difficult to answer as it depends on the particular application for the floor system. Hardie board is thirsty, but that's way too fast. Thanks Paul! The fastest method [for me and possibly other dilettants] is to stroke the knife at a diagonal to the comb marks, top down, center out, pushing all the air before you with short, overlapping strokes.-Thinset needs to be pretty darn wet: Needs to stay put when combed, but should be soft and shiney. But a mortar bed does have advantages. ), Schluter SET, ALL-SET, FAST-SET or an unmodified thin-set mortar is recommended. Set ceramic and stone tile over the KERDI membrane with unmodified thin-set mortar, including large format tiles. We installed cement board on the walls, and today when we attempted to apply the Kerdi membrane we could not get it to adhere. Will be doing a bathroom gut and will be laying durock cement board over plywood sub floor. I used 1/2 Hardibacker board over the studs and then used the Kerdi membrane over the Hardi. Properly waterproofing a shower area sharing a living room wall, Can I use cement accelerator to decrease setup time of modified thinset. Ready to join the 100,000+ homeowners matched with pros? We think it is the cement board (Durock) sucking the moisture out of the unmodified thinset. Once the wall is prepped, use a primer that is compatible with the KERDI membrane so that it will properly adhere to the wall. Also are you saying that you wet ("booking the Kerdi") the Kerdi, as well? Finally, use a roller or brush to ensure that the membrane is secure and has no wrinkles or air bubbles. Step 3: Apply Thinset. Additionally, all thin-set mortars should be suitable for use in wet or feature depths of up to 1/8 inch. Once its cleaned, use caulk to seal all of the seams where the cement board meets the walls. Firstly, it is important to ensure the wall is adequately prepared and that it is smooth, flat and free of defects. Need help liner vs liquid membrane question. And second, since it's foam, the board is super easy to cut with just a utility knife. A lot of folks like using cement board but it's heavy and requires a waterproofing membrane over it. If youre not careful, the boards can also leave behind abrasive sandy crumbs that can cause damage to your shower base or tub. The grid lines on the surface are incredibly helpful for installation and making neat cuts. We think it is the cement board (Durock) sucking the moisture out of the unmodified thinset. While cement board and grout are not waterproof, Kerdi is and can even be directly installed over drywall. The main issue caused by non-waterproof cement boards is the eventual warping and damage to the tiles, making it difficult and costly to fix without removing all the tile and starting over. The bag says Mapei floortile mortar, it was the only unmodified thinset at our hardware store. They are absorbed into the surface material and help keep moisture away from the substrate surface. Or will the Kerdi membrane (with seams taped with kerdi band) prevent each board from moving independently? It is lightweight and made of expanded polystyrene. Schluter says that the Kerdi membrane and tile can be installed over standard gypsum wall board without any problems. All it takes is the right preparation. Like cement board, the boards are heavy and hard to cut. The tub flange can really be a pain in the butt when installing a tile tub surround. That means that you do not have to rely on a surface membrane or worry about the board failing if the core is exposed to water. Unlike cement boards, you can bend this material without it breaking. The foam core surrounded by synthetic cloth on both sides and adhered with resin glue is. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. You have to seal every little hole in the floor so the underlayment doesnt seep into spaces below. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. The great thing about Kerdi Board is that it is lightweight and easier to maneuver. I want to mount a cast iron bathtub, but not pull down my 1905 plaster and lath. Cement board is the industry standard when it comes to tile substrates and the most preferred among professionals when installing porcelain or ceramic tile. see Prop 65 WARNINGS. This flexible polyethylene layer is easy to install and can protect the tile from both cracking and moisture. I still wet the walls first. No bulges either, but definetly no thin spots.-Not paying attention to the direction of the comb. Bulk update symbol size units from mm to map units in rule-based symbology. The product involves an extruded polystyrene foam panel, with specialized reinforcement materials on both sides. All shower/tub areas should have concrete board (I prefer hardiboard). With that said, the key benefits of Kerdi Board include: While cement board may be the most common and widely-known tile substrate, Kerdi Board is giving it a run for its money. When applying thin-set mortar, the manufacturers instructions should be followed closely. Anytime Mongo. A quality underlayment will also serve as a waterproof barrier between the subfloor and the tile surface. We like that the Kerdi membrane material installs easily over almost any substrate, including standard wallboard. The completed assembly takes the place of more traditional backer board when installed over 3/4-inch wood subfloors. Thanks for contributing an answer to Home Improvement Stack Exchange! It only takes a minute to sign up. I circled one area, but there are lots of these edges." - Lisa Jasper The Kerdi band should be smooth and flat - not wavy/ "3) there is no membrane of waterproofing on the hardboard across from the "wet wall" after 5 1/2 feet up. Kerdi Membrane is a product of Schluter systems. It is a topical waterproofing layer that is put over the substrate to keep water from getting to the wood frame and nails. Why do you think each board should be able to move at all let alone independently? The cement board can also become weakened and start to flake away when it absorbs moisture, causing ugly spots and patches to start appearing on the wall. Additionally, a liquid water-resistant membrane should be applied over all surface areas before installation. DIYers on this forum seem to have nothing but problems with Hardi. There is a product called Kerdiboard you might want to look into. Spacers are the next step. As far as the tile/prep work, you are right that he is shifting the blame. Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. I would get someone else. But there are downsides. Not even the plumber's fault as it was just a bad valve. This liquid waterproofing solution does more than keep water away, it also promotes tile adhesion and prevents cracking. If you are good with a trowel and understand how to set up and use screeds as a guide for leveling or forming the mortar, pouring a traditional mortar bed may be a good alternative to tile backer board, especially on uneven or sloping floors. Allow the adhesive to cure for the amount of time recommended by the adhesives manufacturer. The manual can be found here: http://floorelf.com/waterproof, I would say unless you are experienced in working with Schluter-Kerdi waterproofing membrane kit, then I would say work with an easier waterproofing approach, either liquid waterproofing or a combination of liquid and traditional waterproofing (plastic covering the wood frame). It installs with screws, then you tape the joints & screw holes and install your tile. Press the Kerdi Membrane into the Thinset Mortar with firm, even pressure to achieve full mortar coverage. modified thin-set mortar is not recommended to set ceramic and stone tile, including large format tiles, over the KERDI membrane. Yes, Kerdi membrane can be installed over plywood. To line niche shelves, for instance. Cement board and grout are not water proof, if there's Kerdi no moisture is ever going to be able to get behind it. If you want added info there's an old Kerdi thread here. I imagine we could share some good stories. Answer (1 of 3): Schluter recommends applying Kerdi over drywall for walls, however, my local building code will not permit this practice - the local building code requires cement backer on the walls of a shower enclosure, therefore, I have done this successfully many times. Underlayment is designed to smooth out uneven areas of the subfloor and form a rigid layer that prevents the flooring from bending. If installing large format tiles (over 15"), be sure to give the Aquadefense at least 8 hours to cure first. Your real issues are the lack of proper corners on this shower. However, if installed on drywall, it only protects one side. The problem is on the back side of the drywall, which is not protected. Will be replacing tub shower combination with tiled shower in my home. To create a watertight shower assembly, we installed Schluter's Kerdi membrane over the drywall, just as we would for tile.Write by:. When cleaning thinset off of Schluter membranes, the manufacturer recommends using a wet sponge and taking care to avoid any scoring or inconsistencies on the surface of the membrane. For all the substrates listed in this Handbook (e.g., gypsum board, cement backerboard, etc. The difference between the phonemes /p/ and /b/ in Japanese. However if installed on drywall it is only protecting one side. You absolutely need to include some sort of substrate (cement board, green board, regular drywall) with the Schluter-Kerdi waterproofing kit. Start by cleaning the cement board with a mineral oil soap; this will help reduce mold and mildew growth throughout the life of the shower. When doing so, it is important to ensure that the drywall surface is clean and free of dust, grease, and loose paint. If you choose to use Aquadefense as a shower pan liner, be sure to continue it up the walls at least 6", tying into your waterproofing on the walls. There is no cutting or fitting of boards, and a mortar bed is good for leveling and flattening uneven or out-of-level floors, which are common in old houses. This creates a strong, waterproof tile backer that also functions as an uncoupling membrane. Sledge hammers for the floor, that might take a bit of time. True cement board (Durck, Wonderboard) is my first choice as a tile or Kerdi backer. Additionally, the drywall should be primed with a latex primer before applying the Kerdi membrane. And by 'booking the Kerdi' I mean we put it in the bathtub, sprayed it with the handshower, then booked it (just like wallpaper). Cement board is readily available and relatively inexpensive (about $10 for a 3 x 5-ft. sheet). Kerdi 3 ft. 3 in. To learn more, see our tips on writing great answers. Following the instructions for the product being used and ensuring that all of the necessary steps are followed will help to ensure a successful installation. You probably have to go to a big box store's special order desk or find a specialty tile supplier to find it. Kerdi's systems are fairly reputable. If I go the kerdi membrane route, do I still need to tape the joints before installing the kerdi membrane . We tried adding water to the thinset, we tried using a larger notch trowel, but nothing seems to make the Kerdi stick. Caulk the gap. ", Signed,Never Hung Kerdi A Day In Her Life. Ceramic Tile Advice Forums - John Bridge Ceramic Tile, http://www.youtube.com/watch?v=G4HjHT6_cUo, http://www.youtube.com/watch?v=wEt6irjJCI0, My master suite addition & full bath to 1/2 bath renovation. The type of bonding mortar used to apply KERDI must be suitable for the substrate and must penetrate and engage the membrane fleece. DensShield is one common brand. . Now there's nothing particularly wrong with fiber-cementit's just not my first choice. We ended up sponging the Hardi and wetting and booking the Kerdi (a la wallpaper), and that made the installation go much smoother. Cement board comes both in 1/4-inch-thick and 1/2-inch-thick versions. One of the company says they are going to apply kerdi membrane on the drywall, then tiles onto the kerdi membrane, and as such as cement backboard would not be required. Kerdi membrane can be used on cement board, drywall, and, as you may have guessed- greenboard. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? Retired Moderator - Theatre Guy (and computers). When it comes to installation, a Schlter system is typically easier to install than a cement board, and it also allows for more design freedom as it does not require a traditional waterproof layer. It is a fast process that is hard to mess up if you do it right. In a perfect job, it will waterproof. Properly waterproofed Hardie board should last for many years. When screwed to the framing, thin strips of cement board fracture more easily than thin strips of fiber-cement. The best answers are voted up and rise to the top, Not the answer you're looking for? To waterproof Hardie board, you should choose a quality sealer that is designed for use on cement-based sidings. How to adhere edge of bullnose tile to drywall as trim for shower/tub surround. It is important to waterproof Hardie board to make it more water-resistant, as well as to protect the materials from the elements. WATCH HERE: https://www.youtube.com/watch?v=3TRLd2HYhbU&list=PLO47JMsdYGrkxM_ZkOc3lMnsVhTqj80bB#justdoityourself #lovingit #p. By the time you switch from the RG application to the Kerdi installation, it should be dry. A mortar wall is better and can be customized easier. Since my guys and I will be doing this for the first time next week, I 'd like to take advantage of your 'learning curve.' In general, the Schlter system is typically more expensive than a cement board, and some people may find this an attractive option for its long lasting, easy to maintain qualities. Your Get free, zero-commitment quotes from pro contractors near you. These multifunctional tile substrate and building panels are thus perfect for creating bonded waterproofing assemblies with tile coverings. Then you can apply a thin layer of KERDI-FIX to the board, the membrane over top . Installation instructions vary depending on the type of Kerdi membrane being used, but typically the membrane is applied directly to a clean, dry plywood surface that is free from dust, dirt, and other debris. Connect and share knowledge within a single location that is structured and easy to search. #4 You could be adding a good 1000 pounds to your install too. This product is available in 3/16", 3/8", 1/2", 5/8" 3/4", 1" 1-1/2" and 2" thicknesses, allowing for a wide variety of installation options. One of the major benefits of opting for Kerdi Board over cement board is the ease of installation. Re: Kerdi on shower curbs. Not everyone knows how to do mud and lathe it's so old school plus it wears you out, ive been a setter for 27 yrs and I have yet to go back to one of my showers I installed using perma base or durock, with a liner, i have started using waterproofing such as redguard or aqua-defense. Installation; As the GoBoard is very lightweight, it becomes easy to . When installing Schluter Kerdi Membrane over cement backerboard: Should I use Alkali Resistant Mesh Tape and thinset on the seams of the backer board (for long term durability to prevent each board moving independently thus preventing cracking) prior to installing the Kerdi membrane. Once you have determined the type of thinset, its important to also consider the weather conditions during installation. Then you can apply a thin layer of KERDI-FIX to the board, the membrane over top, and use a rolling pin to press it down and ensure a secure bond. Install an Uncoupling Membrane Between Concrete and Tile. Are there tables of wastage rates for different fruit and veg? You troweled on thinset combing it out then pressed the Kerdi into place? I hope you made the guy flood test his work prior to tiling the shower floor. There are many different types of underlayment to choose from, but they all serve the same purpose. The waterproof membrane isn't a substitute for the substrate. What are the differences between "paperless drywall" and "cement board"? Do the prefab Schluter niches like the double unit 12 by 28shelf have a built in pitch to the bottom and middle shelves to drainoff water as shown in niche that you built in that thread? Schluter approves their waterproof Kerdi membrane over drywall. We tried adding water to the thinset, we tried . First, felt paper is stapled to the floor and covered with expanded metal lath. I have watched it done 10-15 times, have good skills, and if I tried to make large mortar walls myself it might like a little kid threw up concrete Should I use Kerdi membrane or cement backerboard? Sloped Shower Tray KST1220/1525 - The Home Depot. if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[580,400],'remodelormove_com-large-mobile-banner-1','ezslot_17',164,'0','0'])};__ez_fad_position('div-gpt-ad-remodelormove_com-large-mobile-banner-1-0');As an added precaution, you may want to consider to adding a water-resistant layer afterwards, such as a caulking or flashing tape. Schluter-KERDI is a pliable, sheet-applied, bonded waterproof membrane and vapor retarder with limited crack-bridging capabilities. ".1) is is okay to use kerdi board instead of ditra on the floor? if you go with vapour barrier, then cement board. After priming, use an approved adhesive to adhere the KERDI membrane to the drywall, making sure the edges are well sealed and joints are tight.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[468,60],'remodelormove_com-medrectangle-4','ezslot_12',156,'0','0'])};__ez_fad_position('div-gpt-ad-remodelormove_com-medrectangle-4-0'); A successful installation of KERDI requires well-prepared surfaces and a proper application, so take the time to properly prime the drywall before installation. Preparing drywall for KERDI membrane requires a few important steps to ensure a successful application. When I do another shower I'll use real cement board, not Hardi-board. Fiber cement board is a variation of cement board that is made from compressed cement and sand and reinforced with wood fibers throughout. if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[728,90],'remodelormove_com-box-3','ezslot_2',173,'0','0'])};__ez_fad_position('div-gpt-ad-remodelormove_com-box-3-0');Yes, you can put Kerdi membrane over cement board. I've seen preferences regarding HardieBacker and the cement board products such as Wonder Board. Is it ok to fasten a shower surround to Schluter Kerdi curb? We don't expect people to master this and in fact I know maybe two guys in my area (live in big city) that could do this. The benefit of using kerdi is we can lay it over drywall, We've added a "Necessary cookies only" option to the cookie consent popup. ), Schluter SET, ALL-SET, FAST-SET or an unmodified thin-set mortar is recommended. It is also widely available and a relatively inexpensive option approximately $10 for a 3-foot by 5-foot sheet. Here is a video off the Schluter-Kerdi website that describes how to apply the waterproof membrane on top of the substrate (gypsum board in this case): http://www.schluter.com/schluter-us/en_US/Shower-System/KERDI-SHOWER-KIT/Schluter%C2%AE-KERDI-SHOWER-KIT/p/KERDI_SHOWER-KIT. Most cement-based thin-set mortars are suitable; however, it is important to check the manufacturers instructions to ensure that the product is approved for use with Schluter systems. True cement board (Durck, Wonderboard) is my first choice as a tile or Kerdi backer. Cement board is the most common and widely-known backer board. Yes, KERDI membrane will stick to cement board. Your email address will not be published. The Ditra uncoupling design is lightweight, durable, and minimizes the possibility of cracked tile and grout. We just went through a learning curve on the Kerdi and Hardi. The perfect fold is tricky and many of my first steam showers where built without the sealed slip joint. As such, many homeowners and professionals find themselves wondering whether Kerdi Board or cement board is the better tile substrate. I've never had a failure. This is the traditional tile backer. I used to "trust" the Kerdi and drywall until I had a shower that the valve broke inside the wall cavity four years after being put in. Because it can let some moisture wick through it, you have two choices: put a moisture barrier behind it to protect the structure, or, waterproof the front of it. On the downside, the cement boards are heavy, somewhat difficult to cut and can leave abrasive sandy crumbs that can damage tubs and shower bases if youre not careful. I guess that why it was so frustrating that cement board is just sooo thirsty. Kerdi Board is expensive, but I can justify it because it saves time, and it's a joy to use. New England. If a law is new but its interpretation is vague, can the courts directly ask the drafters the intent and official interpretation of their law? In order to determine which tile underlayment is right for your project, you need to know which issue youre trying to solve whether its preventing subfloor cracks from transferring to the tile, soundproofing, moisture protection, or providing more rigidity to the tile. The shower is ready for tile. 120 sq feet including the floor. Required fields are marked *. #2 - Your suggestion has plenty of merit though. Both Kerdi Board and cement board are designed to smooth out uneven spots on the installation surface, create an unbending layer that wont flex underfoot, and also provide a waterproof barrier. What do you mean it doesn't adhere? The mortar does . As a contractor, I have been using Kerdi since it came out. When screwed to the framing, thin strips of cement board fracture more easily than thin strips of fiber-cement. Is a PhD visitor considered as a visiting scholar? To line niche shelves, for instance. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design. (3ft-3in wide)Or will the Kerdi membrane (with seams taped with kerdi band) prevent each board from moving . We want that inside corner able to move. Regardless, cement board is a great, trusted tile substrate that will work well on both walls and floors. Various products can be used to waterproof shower walls such as water-resistant drywall and cement backer boards. The thickness of the tile is important, and should be known, but not because it changes the method of building. If done according to manufacturers instructions, it will seal nicely. Any competent tile contractor would float the wall in mortar giving you a stronger, level, perfectly flat, and square surface to properly install tile. I also used a larger sized trowel than the one recommend by Schluter. However, a cement board is generally easier and less expensive to replace if a repair is needed. BTW the older Kerdi thread referencedwas excellent. Since KERDI is impervious, it does not deprive the mortar of its moisture.
