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Stopped by the local supply house to buy some Durock and thinset. The clerk at the store told me that I should put fortified thinset on my plywood subfloor before I put down 1/2″ Durock then another layer of fortified thinset on the Durock to lay my tile on. I’m not a professional but this isn’t my first day on the job. I’ve never seen or heard of putting thinset on the plywood. Is this the new plan?
Thanks for your help,
Randy
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Replies
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Randy: Putting thin set under the Durock is the best way to fill and stabilize the board. Use a 1/4" 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. Do this and you will not have any gaps between the Durock and plywood. All loads will be transferred to the sub floor.
*Done a gazzillion floors with durorock and wonderboard and never found the need to thinset under it. Been back to many of the jobs years later and the floors were all great,,no problems. I ALWAYS use screws though........never nails..Insures a tighter job. I'm sure thinset is great under the boards but I havent had any problems yet with out it.
*I always thinset under the Cement Board. It just feels better knowing that every single inch of the board is supported firmly. I also use a notched trowel.Maybe overkill but I'll keep doing it.
*Andy...do you use the recommended fibreglass mesh tape on the Durock joints?
*Have you ever done one on cement floor?? What did you do to replace the lack of ability to screw down ???? How about leveling out a high spot ???
*All backerboard manufacturers specify their products to be installed with thinset mortar and either galvanized hi-lo-roc on screws or galvanized roofing nails. Durock even provides picture installation instructions on each sheet for the reading impaired. The thinset acts as a leveling bed for the backerboard. No thinset..no warranty. Use a dry set mortar under the backerboard and save the expensive polymer modifed thinsets for the tile installtion. Yes, the joints of all backerboards should be taped and filled with the setting thinset prior or during tile installation.You dont install backerboards on concrete slabs. Sounds like you either need to remove and replace a section of the slab, or use a self leveling compound.Dave
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Stopped by the local supply house to buy some Durock and thinset. The clerk at the store told me that I should put fortified thinset on my plywood subfloor before I put down 1/2" Durock then another layer of fortified thinset on the Durock to lay my tile on. I'm not a professional but this isn't my first day on the job. I've never seen or heard of putting thinset on the plywood. Is this the new plan?
Thanks for your help,
Randy