For more surface preparation options, view our line of flooring installation systems products. Theres a dip about 38 deep by 2 feet wide by 5 feet long. Cement board installation on floors avoid these 5 mistakes. Structolite versus floor leveler 2 answers i have a 30 year old fiberglass tub with no support under it 1. Preparing your surface is the most critical task of any tile or stone installation.
In this video, i show you how to tape cement board joints. What you need to know about thinset or mortar the toa blog. I just completed installing 14 hardibacker over a plywood subfloor in my master bath in preparation for installing 12x12 porcelain tile. How to install cement board cbu for floor tile one.
Thinset is much less expensive then those two products. I think the old osb is 34 so literally a fraction of an inch off. Selfleveling underlayment over 14 hardie backer 07152016, 08. The directions clearly tell you the beat in thickness can be no thicker than 14 with that thinset as well as all others with the exception of medium bed mortars. In this video i give you stepbystep instructions to install a. Smooth the top of the mortar every hour for six hours. Tile will be on the durock and part of the drywall 36 up from the floor all the way around the bathroom. What you need to know about thinset or mortar the toa. Taping cement board jointsstep by step tutorial youtube. How to install cement backerboard for floor tile the floor elf. Where to buy not all products are sold at all stores. Mapei largeformat floor and wall 50lb white powder thinsetmedium bed mortar. The thinset goes on top of the cement board to stick the tiles. Scratch the surface with a utility knife to rough up the surface a bit if you.
Layers of thinset would allow you to build up the dip so that its parallel to your floor. Jim and rich have found that durock edges crumble more easily so id expect theyd be more careful with the edges until everything was laid. You should have addressed this with your contract, because its a commonly skipped step. A versatile, trowelable, polymermodified cementitious patching compound for interior use over concrete and approved wood subfloors.
For underneath its recommended thinset to fill any air pockets, on top any areas that are damaged or need filler i personally would use patch, with additive if were recommended for the patch. Another advantage is that its inorganic and thus is not a food source for mold growth. Underlayment 145 floor levelers 57 floor patch 49 waterproofing membranes 33 backer boards. Once laid into the thinset bed the floor becomes a solid, fully supported substrate for your tile thats what you want.
Installing durock correctly on a wood subfloor hearth. Since thinset tile mortar may crack, you may wish to mix it with a special latex additive to increase its strength. Do not use usg durock cement board with vinyl flooring. Fasten d urock brand cement board with 114 hotdipped galvanized roo. If so, should i use modified or unmodified thinset, or does it make any difference under the cbu. Ive thought about patching that area with dap floor patch, but im not sure. When installing tile on a cement backer board, like durock, or hardie. Usg durock brand x floor patch is ideal for renovation projects and is easy to mix and apply. Because thinset is not affected by moisture, it is best for floor tile and any tile in wet areas, including shower floors, walls, and ceilings and tub surrounds.
Is a 14 notched trowel ok to use for the thinset if needed. Thinset or mortar or thinset mortar, thinset cement, dryset mortar, or drybond mortar is an adhesive made of cement, fine sand, and. You say it is 12 durock over 1 nominal thick plank. Thinset, while it is also sometimes referred to as a mortar is an adhesive. Thinset mortar is your default tile mortar for most indoor and outdoor applications.
Use a 14 notched trowel,spread on the sub floor, place the durock down and take a rubber hammer and tapping the board several times to fill any low areas of the plywood. Custom building products 8 fixa floor 4 primo tools 1 usg durock brand 1 set custom price range. Durock and drywall joint is where the shower stall ends. The most important points here is that you use a high quality thinset mortar and you remove dust and moisten substrate to avoid it sucking the moisture out of the thinset. Im getting ready to tile my bathroom floor with 12 square ceramic tile. Do this and you will not have any gaps between the durock and plywood. Can i use leveling compound between plywood and cement backer board. Mapei ultraflex 1 50lb white powder thinset mortar. Yup youre correct, it was the hhardiboard i was comparing to the fiberboard usg carries, not the cement board. The flooring guy called me and said that jameshardie company tech support said that if he used screws instead of nails they could forego the thin set under the cement board. Apply a supporting bed of mortar or modified thinset to subfloor using a 14 squarenotched trowel. Vinyl flooring over thinset on cementfiber board forum.
I am installing ditra heat over my bathroom floor and schluter foam shower pan over osb. How to install cement board for ceramic tile the spruce. The durock surface will not support a tub for long without crushing. I just finished a job where the original installer used a 316 v notch trowel to install the thinset under the backboard. Durock brand advanced skim coat floor patch s a versatile calcium aluminate floor patch and skim coat for interior use over wood, concrete and gypsum subfloors and over most interior floors, including ceramic and quarry tile, terrazzo, wood, metal and interior concrete, as well as properly prepared residues of cutback and other nonwatersoluble adhesives on concrete and. Cover an area large enough to place the first backer board sheet. I saw the same question on mar 17, 2009 so wanted to try the recommendations of shoving balls of structolite in material squares under the tub and letting it set up. Its a good idea to use a tape that is meant for cement board, since it is designed for this application.
When moisture is present, it will not return to a liquefied state as mastic would. Durock brand advanced skim coat floor patch s a versatile calcium aluminate floor patch and skim coat for interior use over wood, concrete and gypsum subfloors and over most interior floors, including ceramic and quarry tile, terrazzo, wood, metal and interior concrete, as well as properly prepared residues of cutback and other nonwatersoluble. A versatile, trowelable cementitious patching compound for interior use over concrete and approved wood subfloors. Custom building products 8 fixafloor 4 primo tools 1 usg durock brand 1 set custom price range. Modified thinset is the product of choice for most tile installations because of its increased strength and bonding with minimal shrinkage, which means a. Step four how to install cement board on the floor. If you follow all these steps, youll have a stiff, monolithic, crackfree floor. Work gloves and safety glasses are required when using hand tools. Before installation, i used a beltsander and sometimes a power planer to smooth the transition. How to secure cement backer board to a plywood subfloor. I hope that doesnt mean he thinks using thinset under those circumstances is ok.
Do not use 14 usg durock cement board for wall or ceiling applications. Sep 17, 2018 tile backer board may be drywall or cement board. Both durock and hardibacker specify it should be attached to the floor with thinset. Do i have to use thinset under the durock if its just a. Tile subfloor, thickness, deflection installing electric radiant heat pouring self leveling mortar leveling flattening the subfloor installing cement board cbu installing schluter ditra marking guidelines for tile how to lay tile how to grout tile joints cement board replaces the old plaster and lathe underlayment for tile. Although thinset is not waterproof, it is isnt water soluble. I had to patch parts of the floor with 2332 osb and the result is some uneven seams not necessary. The plank subfloor has some gaps in it, maybe 1814 or so. I would only fill the joints that run in the length of the cement board for now.
The plywood subfloor should be at least 58 thick on 16 centers 34. Jan 12, 2016 i am laying down durock cement backer board over plywood durock instructs to trowel thinset over the plywood, then place the durock on it. It is simply put in place to eliminate voids beneath your backerboard. How to thin set cement board to plywood for tile installation. Patch poor subfloors with a selfleveling underlayment for a new workable, flat surface. Hardi apparently doesnt require mortar under its cement board if its screwed. I also have another low spot that is about 14 deep the same size near a different wall.
And for radiant floor heating installations, the thinset must be at least 38 inch thick in order to embed the heating element and adhere the tile. The critical issue is when there is a gap between the subfloor and the underlayment. It is applied to the substrate with a notched trowel. Installing a tile floor is the perfect project for a bathroom renovation. Durable tile floors look sophisticated and are great for wet areas. Mar 07, 2017 in this video, i show you how to tape cement board joints. It is what makes it possible for tile or stone to stick or bond to the backer board. What this does is tie the two boards together and help prevent flexing. Maximum installed weight of the finish system should not exceed 15 psf. Pour the thinset mortar onto the floor thick enough to make a 14inch layer over the existing floor.
Part 2 how to install durock on the floor complete bathroom. I would simply put down the backerboard with thinset under the backer board then screw, not nail it down. A product like mapei plani patch, or ardex sdf, is the correct product to use. How to use thinset mortar to resurface concrete ehow. May 27, 2014 yup youre correct, it was the hhardiboard i was comparing to the fiberboard usg carries, not the cement board.
The thinset is not meant to stick down, adhere, or otherwise attach your backerboard to your subfloor. How to install tile over old thinset home guides sf gate. I installed the hardibacker using modified thinset and roofing nails. For tile backer board such as durock, wonderboard, hardiebacker, permabase, and others the seams between the board need to be treated with 2inch alkali resistant mesh tape. Durock cement board in preparation for a tile floor install. In this last step you need to tape and fill the joints. I taped and covered the joints with modied thinset.
Contractor not using thin set between sub floor and cement. Effects of improper ditra installation the floor elf. Thinset, on the other hand, is used to install tile over cement, cementfiber board and antifracturewater proofing membranes. Ditra, thinset, then tile would make the floor so much higher than the floor outside the bath and that its probably not needed, but wanted to get another opinion. It is a very simple process and i used some fibatape and thinset mortar to seal the cement board joints. When installing tile on a cement backer board, like durock, or hardie backer board, it is critical to follow the manufacturers. At the end of last week, my tile subcontractor screwed durock to the subfloor in a small bathroom without putting thinset down first and has already laid the ceramic floor tiles in a bed of thinset on top of the durock. The only time i use modified thinset is when applying over plywood and with the higher quality ditra set available now, i dont. Ive seen too many cracked and loose floors as a result of people skipping this step. If youre working over a wood subfloor, cement board is the right choice for your tile. Usg durock brand cement board installation guide english. Ive installed a hundred tubs, and removed just as many, and ive never seen one installed directly on cementboard or even a mud floor.
By contrast, leveling compound will dry level, but if your floor isnt level, that may not help you. Thick builds will crack, and the thinset has a lot of sand. Contractor not using thin set between sub floor and cement board. Then a coat of thinset gets flat troweled over the seam. John, it sounds like shes got the tub sitting directly on the durock no tile yet. Not only is thinset a critical component underneath cement board but the other critical component is the fasteners. Selfleveling underlayment over 14 hardie backer jlc.
Failed floor on cement backer boards, why this happens. Before you can replace either material, you have to expose it by removing tiles. How to install cement board on a floor the family handyman. Smooth out the surface of the thinset with a finishing trowel, which has a smooth edge. Easytoapply products engineered to level floors prior to floor covering installation. Use a floor grinder and pass it back and forth over the old thinset until it is perfectly smooth and level. Putting thin set under the durock is the best way to fill and stabilize the board.
Installing tile backer over plank subfloor i am planning on installing tile in my utility room and there is a plank subfloor under the existing wood floor. Spread the thinset over the surface, filling in the low spots and holes. I will be putting down 516 durock over the plywood subfloor. The advantages of thinset is that it can be used in areas where there are high amounts of moisture present. Cement board is used for most floor tile and has all but replaced. Thinset is a mortar that is made of portland cement, silica sand, and moistureretaining agents.
And you wont have the fasteners if you are trying to install it over concrete. I am laying down durock cement backer board over plywood durock instructs to trowel thinset over the plywood, then place the durock on it. You dont have to use the lft under the backerboard. The procedures for patching cement board and patching drywall are similar, but you need different tools to cut the two materials. Because plywood expands and contracts beneath the ceramic tile, grout and tile.
A professional formula, allpurpose mortar, polymermodified to provide good bond strength for floor and tile projects. Dec 14, 2018 use a floor grinder and pass it back and forth over the old thinset until it is perfectly smooth and level. You can now tile directly on top of it as if it were a new surface. Can i use leveling compound between plywood and cement backer. Cb237 durock brand cement board installation guide. Comb out adhesive or mortar in straight, parallel rows as shown below and immediately cover with panel.
Floor priming will improve the bonding of subsurfaces to your underlayment. There are specs for the thinset in the durock application sheet, referenced in the wiki article in the case of my extension, i cut out the carpet, and lifted the 12 particle board subfloor it was attached to, then put down a layer of thinset, a layer of roof flashing, another layer of thinset, and a layer of durock, screwd down per. Scoop up thinset on the flat edge of a 14inch, squarenotched trowel and spread the thinset across the plywood. Can i use leveling compound between plywood and cement. Fill the spots until the thinset is level with the string. Ideal for renovation projects, this economical usg durock brand ne floor patch provides a smooth skim coat for accepting floorcoverings. I am wondering if i need to wait for the thinset under the durock to dry before i tape and thinset the seams where the durock meets. Heres the right way to attach cement backer board to a plywood subfloor. The most important part of a tile floor installation is prepping the subfloor. Make sure the joists are wide enough for the span and spaced on 16 centers to provide a sturdy floor with no bounce. Thinset tile mortar has a smooth, slippery consistency, similar to mud. I had to patch parts of the floor with 2332 osb and the result is some uneven seams not necessary unlevel where the new osb meets the new osb boards.
On the bright side, there are some options for concrete subfloors. When to use modified or unmodified thinset warmlyyours. Mar 29, 20 with the thinset underneath, the cement board is fully supported as is the tile so theres no weak spots that walking on would damage. Mapei rapid setting 50lb gray powder thinset mortar. Custom offers you one source for the needs of virtually any job. Jan, 2018 failed floor on cement backer boards, why this happens. It holds your tile to the substrate and is used in commercial applications, wet wall applications such as a shower floor, or with heavier tiling materials such as mexican noce tumbled stone tile. Usg durock cement board is not designed for use as a structural panel. Would the thinset level this under the hardibacker.
679 830 99 1167 147 103 1321 1227 1596 1295 428 1413 1553 694 1196 240 1231 795 233 732 521 1006 261 61 393 1004 625 810 850 338 752 1454 5 217