rated plywood or OSB with an Exposure 1 classification or better. felt or 4-mil polyethylene and attach with 1/4" galvanized staples. thanks everyone for the info. Most of the time I was on the phone and you wouldn't believe some of the stuff I heard...from "professionals". Your new layer of underlayment needs to be perpendicular to the joists just like the subfloor is. though. The cement backer boards like these are normally quite expensive. Hi Pat, you'll be fine with thinset under the durock on the osb. You need double floor for the stone Pat. I'll send for some info. Place the first sheet over the mortar bed. Cement backer board is often used as a tile base on plywood or OSB subfloor. Lastly, I don't know squat about Ditra, Kerdi, or any of the Schluter products so I'm not considering them at the moment. Fasten to the plywood with 1-1/4 DUROCK Brand Wood Screws or 1-1/2 hot-dipped galvanized roofing nails,spaced 8 o.c.in both directions and Install the First Sheet. Deflecto numbers look good but the deflection between the joist is what kills most floor. Cement backer board is mainly used as a sub-surface for tiling. I applioed screws every 8 inches and it does feel sturdy. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Cover base with USG Durock™ Brand Tile Membrane, 15 lb. Appreciate the quick reply! Highlights: - Can be used for interior and exterior applications. The cement backer boards like these are normally quite expensive. when tapeing the seams of the durock do i also you the unmodified thinset?? The 1/4" thickness helps eliminate transition trim when abutting carpet or wood fl ooring and minimize level variations with other fi nish materials. PhilandKathleen | Posted in Construction Techniques on August 10, 2002 05:31am We are building a seasonal home in Northern Michigan (therefore it will be subject to lots of freezing/thawing). It can be applied directly over old substrate on countertops to … You can cut it by scoring with a carbide-tipped blade or by using a circular saw or jigsaw. You will have to add some more ply to the floor too, 3/8" min 1/2" is better. Thinset is the correct term. Hey Termite, you misunderstand my criticism. Mix powdered latex-reinforced cement mortar … APA span-rated plywood or OSB with an Exposure 1 classification or better. Planning and patience along with these tips will help ensure that you install the quality of finished flooring you are looking for. We have taken old flooring out down to subfloor, installed OSB and have durock to lay. A 15/32” sheet of OSB is just over $15, making it a bit more expensive than drywall of a similar thickness. Countertops 1/4", 1/2", 5/8" thickness Minimum 3/4" APA span-rated plywood or OSB with an Exposure 1 classification or better. They are set on using Durock (yuck, I like Ditra better). On the floor outside the shower, I have removed all existing tile, thinset and cement board, I am going to use an UNMODIFIED thinset to apply Ditra then tile over the Ditra with a modified thinset. Good thing you said marble. For a better experience, please enable JavaScript in your browser before proceeding. Cement board over top, or rip out what I had just finished and put cement board directly over the plywood subfloor? August 11, 2020 at 6:07 am. I never done this before . Durock is a reliable cement product that contains glass mesh. The rough or embossed surface of … With the plywood in place, install the backer board as you normally would. Cutting with a power saw raises copious amounts … (19 mm). Hope you didn’t like your beautiful new tile floor! BC plywood over the old subfloor, using construction adhesive and driving 1-1/4-in. hopefully, everything works out. Leave a slight (1/16") gap between each board so that the plywood can expand and contract over time. The plywood adds stiffness and stability to the floor. (16 mm) thickness Minimum 3/4 in. Typically 8" along the edges and 12" in the field. Out with the OSB. pitterpat. November 13, 2020 at 9:38 am. screws every 6 in. The industry is full of hacks that say they are going to apply "mud" on certain installations when all they do is spread thin set mortar. ... Durock can be used for both internal and external situations. I think it's always best to follow the manufacturer's directions. View Full Version : Durock over OSB. DO NOT install tile directly over OSB (that's what the thinset manufacturers are referring to). DITRA allows for ceramic tile application over single-layer plywood or OSB subfloors on joists spaced up to 19.2" (488 mm) o.c. STORAGE & MIXING Roller Bear must be stored at temperatures above 4°C (40°F) and below 40°C (104°F), off the ground, in a dry Offset the underlayment seams from the subfloor seams by at least a foot or so for best results. or OSB with an Exposure 1 classification or better. - … 1st time. It's ok to put a layer of thinset between the OSB and backer board. Do not 1/4 turn the underlayment direction from the subfloor. B. That Durock was held down with roofing nails, no screws, no thinset under it. RealPlayer will not go on this machine as long as I can keep it off. Cement backer board on concrete as a subfloor or underlayment is usually not recommended or needed. 09-27-2005, 03:02 PM. First off, why on earth would you put thinset UNDER the Duroc? That is what I thought, but I wanted to be sure. Mud the tape when you set the tile, what ever you use on the tile will work fine. Home builder wants me to tile a couple of floors. I use a roofing nailer and nail the kazoot out of it. I would then put ditra on that. The OSB is what is causing the creaking and popping. jim VanBergen says. Boy would they get mad when I'd point them to the Duroc installation instructions and show them. http://www.contractortalk.com/showthread.php?t=9321, http://www.custombuildingproducts.com/docs/tech_bulletins/TB12%20Bonding%20to%20OSB.pdf?USER=pro\&LANG=en, VerticalScope Inc., 111 Peter, Suite 901, Toronto, Ontario, M5V 2H1, Canada. :). A 7/16” thick 4’X8’ sheet of OSB costs only $9. Reply. Mix powdered latex-reinforced cement mortar with water as directed on the package in a clean plastic bucket. 1/4" USG Durock® cement board is an ideal substrate for fl oor and countertop ceramic tile installations. Installation of Durock to OSB. We have 3/4 OSB and want to attach Durock to it. Durock and most other manufacturers want you to use modified so......? OSB panels provide an excellent base for many types of finished flooring including ceramic tiles if careful attention to the construction and preparation of the subfloor is paid in order to avoid costly callbacks. Question: is it necessary to use thinset between OSB and durock or can you screw straight down without thinset? Roller Bear is suitable for use over OSB, plywood, glass-fibre-faced gypsum, cement board, concrete, and brick. Anyway they're buying. A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. You do NOT mud the seams and tape them. any hints?? I brought 1/2" DUROCK and planning to place ceramic tile on top of the durock. Cut fiberglass mesh tape to fit in a single layer over every joint where the panels meet, but do not overlap the tape. However, this is thinner than the ½” drywall and will provide less soundproofing. Already ck'd deflocto meter, deflection is OK. What do you mean, plywood over the thinset?:). with d-rock it will be way high, even with the 5/16". Try laying tile over 1/2″ Durock or Hardie and see what happens when the joists are 19.2″ or 24″ on center. Now their is a mix of new exterior grade osb and old OSB (i thinks its interior grade). Home builder wants me to tile a couple of floors. The sub-floor now has a few seams. JavaScript is disabled. Ceramic Tile Advice Forums - John Bridge Ceramic Tile. First of all, .....because words mean things, thin set mortar should not be referred to as "mud", especially on a tile forum. Mud is sand/cement and is applied an inch thick or so as the base for tile. (6 mm), 1/2 in. OSB shrinks quickly once it is installed. Plywood Fasten to subfloor with 1-1/4" DUROCK™ brand tile backer screws for wood framing (or equivalent) or 1-1/2" hot-dipped galvanized roofing Is there a reason why your contractor wants to use cement backer board (Durock) over OSB plywood? But, why wouldn't any of you consider using regular 1/4" HardiBacker vs. the Duroc? You have to check the joists before you do this. Awesome advice. I went back to Lowe’s and picked up DUROCK cement backer board instead, plus thinset, the proper screws , and alkali-resistant fiberglass mesh tape . So, why the need for more sub-floor, unless you don't trust your numbers? shanti says. They are set on using Durock (yuck, I like Ditra better). USG Durock™ EcoCap self-leveling underlayment can be applied with metal lath over engineer- approved, APA-Rated exterior glue plywood or oriented strand board (OSB) (i.e., APA-Rated Exterior or Exposure 1 panels) wood subloors following the Tile Council of North America’s So, why the need for more sub-floor, unless you don't trust your numbers? Wipe dust and debris from the joints between the Durock panels. I'll have to check it out. Currently we are putting ceramic tile in our mud room and bathroom. My husband and I are remodeling a kitchen. I am going to redgard before tiling. How to Tape Durock Joints Wipe dust and debris from the joints between the Durock panels. Tile can be installed over a plywood substrate, and it is actually a fantastic way to make sure you don’t have deflection in your floor. I think they just picked up the the term from drywall installers? OSB comes in slightly different thicknesses than the other materials we’ve discussed. The following backer boards are commonly used for tile flooring in wet or dry areas over wood subfloors: Concrete backer board (Durock and WonderBoard), which is the standard material for tile underlayment. In most cases, you can apply tile directly to the concrete. grade plywood or OSB base across the wood cabinet sup-ports.Position ends and edges over supports.Staple-attach 15-lb.felt or 4-mil polyethylene film using 1/4 galvanized sta-ples over the plywood base. Cut fiberglass mesh tape to fit in a single layer over every joint where the panels meet, but do not overlap the tape. :D. Sounds good to me. The other reply I said was good for tile or porcelain, not stone. :thumbsup: TILE GUY - retired- TROY, MI - Method & Product suitability consulting. The tile was 6 or 8 inch and it had been down for about 12 years on a single layer of half inch Durock over a single layer of 3/4 OSB on 24 inch center trusses!! But if your subfloor boards are tongue-and-groove then 1/2 inch ply over the top (or OSB) would be fine. Paul, if you were to look at a piece of Ditra, you would see that those little squares are actually kinda like dovetails.Each square angles inward so that the thinset locks in to the matt. Thus the need for the added plywood. For flooring applications over a wood-based substrate, laminate DUROCK to subfloor using Type 1 organic adhesive or latex-modified thin-set mortar suitable for bonding cement board. Is there a reason why your contractor wants to use cement backer board (Durock) over OSB plywood? Secondly, it's my understanding that you're looking for a min of L/360 for ceramic tile and double that, L/720, for stone...as far as deflection numbers go. Also be sure to "mud" and tape the seams of the durock with thinset and mesh backerboard tape. (6.8 kg) felt or 4-mil polyethylene By doing it at the same time, you'll lessen the chance of creating a bump at each seam. Countertops 1/4 in. Concrete backer board has a solid concrete core, and both sides are faced with fiberglass. Refer to DuROCK PUCCS EIFS specifications and 3D details for further information. Cover base with USG Durock™ Brand Tile Membrane, 15 lb. Use unmodified thinset, do not treat the OSB. Best recheck that deflecto meter again too. I suggest you use modified thinset for any filling and taping---this is what you will be using to set the tile over the Red Guard any way--so why buy a second product---, New members: Adding your location to your profile helps in many ways.--M--. Just to clarify, I can apply modified thinset to the seams of durock? ; USG: Durock does not expressly exclude concrete, but the material is specified only for minimum 5/8-inch exterior-grade plywood or OSB.One source reports that USG will not officially validate the Durock-to-concrete attachment simply because they have not tested it. Plywood, or even OSB, has its strength running with its length. I think the most common thing I ran into was tile installers who didn't want to use the fiber cement boards because the instructions told them they had to put the mortar under the boards vs. not needing to do it with Duroc. (12.7 mm), 5/8 in. The backer board should be screwed down according to the manufacturers specifications. Already ck'd deflocto meter, deflection is OK. I was going to follow what the manuf. The OSB is what is causing the creaking and popping. Thank you! On a side note, I also siliconed all the screws in the durock and let dry prior to … 1) The backer board must go over a subfloor base, and the although the 2" x 6" tongue and groove along with the backerboard might be sufficient and structurally sound enough for the addition of tile, I would add a layer of plywood. Would really like to see how they do the uncoupling thing...and still keep the tile on the wall or floor. ... Cement board is a great way of going over OSB and the way that you outlined should work perfectly. vBulletin® v3.7.4, Copyright ©2000-2021, Jelsoft Enterprises Ltd. As for watching the video...if I remember correctly...it's RealPlayer. Stagger the joints on the plywood so they don't line up with those on the OSB. Anyway they're buying. Guys...yes...I'm impressed! Add a layer of 1/2-in. I know that you know what you're going to use, I'm thinking of all the people that don't know what we're talking about. Hi Paul welcome. Last time i checked there was a video on how the ditra worked on thier website it was a pretty good one check it out. As in is it bad to use backer on screws over durock and do you think the 1 5/8 screws into this will hold up? James Hardie: HardieBacker specifications specifically exclude concrete as a base for installation. recommends. I had to cut some pieces out of the floor due to rot and replaced it with new OSB. when it comes to breakfast, the chicken is dedicated, the pig is committed. Reply. Durock 1-1/4" Screws (600 count) DUROCK Screws are high-quality, corrosion-resistant fasteners specially designed for attaching various types of backerboards and underlayments to wood or steel framing members. If they aren’t attached to each other then I think you have to go with 5/8 ply or 3/4 inch OSB. What these guys said. Helping You to Do It Yourself! OSB shrinks quickly once it is installed. I used to work for JH as technical rep. Okay guys, I have a couple of questions after reading this. We plan to install 12″ tile over durock. Cover the entire OSB subfloor with a layer of 1/4" plywood underlayment. Secondly, it's my understanding that you're looking for a min of L/360 for ceramic tile and double that, L/720, for stone...as far as deflection numbers go. Cementboard comes in 4 x 6-foot sheets with brand names such as Durock, WonderBoard and HardieBacker.