Asked on Oct 27, 2012

Anyone have any advice about laying tile? Just ripped up the carpet it our basement bedroom. Concrete floor.

LiveLoveDIYKMS WoodworksSherri


I was wondering if we needed to get all of the carpet glue up off of the concrete or if we could just tile right over it. I've tiled before, but never over concrete. Suggestions? Also, the floor is level (minus the glue!)
8 answers
  • FloorNerd
    on Oct 27, 2012

    heat gun it and then scrap it off, it should come off like that.

  • Straight Nails Construction
    on Oct 28, 2012

    Use some sort of product that will remove the glue from the surface, in this case, the concrete. You may want to add a step to this project to insure you have no cracking of the grout joints of the tile. There is a special type of "paint" that you can buy, (at any home improvement store) especially for the underlayment of tile over concrete. This "membrane" will allow the mortar bed and tile some flexibility, in the case of the concrete moving over time, thus eliminating the cracking you sometimes see in tile grout lines over concrete. Usually it takes two coats to have the proper coverage, then tile as you normally would.

  • KMS Woodworks
    on Oct 28, 2012

    If there are no current cracks in the slab then you should be fine without a "de-coupleing membrane" (ditra) I have used a heavy duty floor scrapper to remove this glue, goo gone and even a belt sander. Depending on how thick the chunks are you may even get by by not doing anything. if nothing is over an 1/8" and you use a generous mud bed you can get by. Saltillo tile is set with 1/2 x 1/2" notched trowel and the concavities of the tile back-buttered...this process has the mud bed a bit over 1/4" thick.Another option would be to skim the entire floor with a leveling compound like level quick...

  • Creatively Living
    on Oct 28, 2012

    I would scrape it. The worst is putting all that work in and then having a tile crack or come loose and be unlevel a few months after the tile job. You could probably heat it easy enough to scrape with a blow-dryer.

  • Heat gun like Mark Potter suggested may work, just be sure to have plenty of ventilation in case of fumes. A good scrapping will also work. You can rent power scrappers if the glue is really bad. Sanding might work, but if the adhesive is really gummy then you will go though a lot of paper in the process. Ditra as KMS said may or does not have to be used, even if you do not have any cracks. Ideally I use the stuff all the time on cement floors. Primarily because of the insulation factor. Although not a lot, it does isolate the tile from the cement. I would also consider a heat mat install before you lay down the tile. You do not have to do the entire floor although suggested, If you know the lay out of the room, where your feet are going to be in contact with and were tables, bed, and other furniture will be resting, you do not need to heat those areas. The install of the heating mat is pretty simple And the room will benefit greatly as a result. Even if you have good heat in the room, Taking a little chill off of the floor will go a long way in increasing the comfort of the room even if you have a small carpet put down.

  • Sherri
    on Oct 29, 2012

    Make sure that your floor is actually level, before laying tiles, by applying a self-leveling compound.

  • KMS Woodworks
    on Oct 29, 2012

    The heat mat Woodbridge mentioned is a great idea...I have installed both the "warmly yours" and the "suntouch" versions. some over slab others over subfloor. For the slab installs I like to use a hot melt glue gun to tack the matt in place at a number of locations. Then I will add level quick to embed everything and "protect" the mat before the tile goes in.

  • LiveLoveDIY
    on Oct 29, 2012

    Thanks everyone! So helpful!!!

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