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Community and Q&A

Does the floor mortar bed and wall tile mortar contain asbestos?

bloated | Posted in General Questions on


I live in a home in Montreal built in 1959. I started to gut the bathroom and then remembered once reading something about asbestos in building materials. Should I be concerned about asbestos in the mortar beds under the floor and walls? There is also a layer of mortar over the drywall and on metal mesh that is behind the mortar beds.

Dan Montagano

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  1. charlie_sullivan | | #1

    I don't know about mortar. I do know that my 1970 house in NH has 2% asbestos in the drywall compound, 5% asbestos in the popcorn ceiling texture, and had some in the floor tile as well. You can send samples to a lab for analysis--might be worth collecting a range of samples and sending them out.

  2. GBA Editor
    Martin Holladay | | #2

    I imagine that the likelihood is low that your mortar contains asbestos. But there are big asbestos mines in Quebec, so your Montreal location must be taken into account. Some 20th-century masons did mix asbestos into their mortar, but it's unclear how common the practice was. Check out this link:

    As Charlie said: if you are concerned, have the material tested.

  3. bloated | | #3

    Charlie and Martin,

    Thanks for your responses and advice (and link). I've done a good deal of work in this house over the years, only now learning about the use of asbestos in construction materials. I'll go ahead and call a testing lab tomorrow morning.


  4. rocket190 | | #4

    As others have mentioned, lab testing is very affordable. In my area you can have a certified asbestos inspector survey your entire house, send in lab samples, and provide a report for around $400 for a residential structure. Individual lab samples are about $12 each.

    Regardless of if it's asbestos, use BMPs....keep the floor wetted down, seal the area you are working on from the rest of the house, and wear a cartridge style respirator n100 type for asbestos and lead work.

  5. bloated | | #5

    Rick, I sent in 5 samples this morning and was told results would arrive tomorrow. I will post here. BTW, the fee here was $120/sample for the drywall/compound/mortar mixture and 90 for the cement behind the wall tiles. With the drywall, if the first sample contains asbestos then they stop there and only charge for the one test.

  6. bloated | | #6

    Results show no asbestos!! The company that performed the test also published a paper a few years ago regarding asbestos contamination while removing drywall. They determined that so little is released that no abatement is required. The study method and results can be viewed at the link below. I preferred to have the testing done anyway for my own peace of mind. Thanks everyone who responded.

  7. Expert Member

    Good news! And thanks for the link.

  8. rocket190 | | #8

    Excellent news. Those prices are definitely higher than what we pay, but I'm sure the peace of mind was worth it. FYI, the most common positive items are as follows:

    9"x9" resilient floor tile
    Black linoleum mastic
    Window glazing
    Old linoleum
    Pipe joints that look like they are wrapped with aster of Paris

    Less common is transite board and vermiculite insulation.

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