Asked on Dec 14, 2011

Hello everyone, I've heard alot of good things about this site.

Straight Nails ConstructionKMS WoodworksWoodbridge Environmental


I have a tile question. I plan on installing a tile floor in the living room \ hall way of my home,in the past i've either just laid the tile right over the sub floor or put down backer board and laid the tile on top of that with thinset with good results either way.The Home-Depot site and the Hardi-Backer site now recomends putting down thinset between the backer board and the sub-floor and thinsetting and taping the seams like you would drywall. Is this really necessary? Are there any advantages or disadvantages to doing this? Thanks for your opinions
3 answers
  • Welcome Mike, Ideally putting down even just a thin layer of thin-set on the floor before you put the Hardi-Backer down helps. What it does is helps prevent any movement by gluing down the boards. It also helps level any low spots that can weaken the cement boards. Also by using the cement thin set with fiberglass tape on the joints makes the floor much stronger and helps prevent any side to side movement should the wood floor swell or shrink with the weather. Another way to do this is if your floor is thick enough, and you know for sure that there is no flex in it between the joists. You can put down a uncoupling layer such as Schluter Detria Mat. Here are the directions on how to use this product. Yes there are advantages of doing it the way the manufacture suggests. Its is the right way to do this and it will assure you that if you follow their directions that you should have successful results that will last a lifetime.

  • KMS Woodworks
    on Dec 14, 2011

    If you are "mating" this tile surface to a normal hardwood floor in some other room the use of 1/4 backer set in mastic / thinset will bring the final tile height to that of the standard 3/4" thick hardwood. by setting the backer you greatly reduce the chance of flex...which is tiles "Achilles heel". If I am laying a very large floor I will often set the backer with mastic and use my "roofing" nail gun to nail it off. This is tons faster than screwing it down. For small jobs I often screw it hauling the compressor in the truck sometime requires extra trips when the tile saw and equipment are loaded. Taping and mudding seams helps with minor tile leveling issues too

  • Straight Nails Construction
    on Dec 14, 2011

    I just added thin set to the backerboard before screwing to the floor... this was a great addition that will add to the quality of work.

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