Bitumen smell

Discussion in 'Subfloor Preparation' started by Gmm001, Dec 1, 2022.

  1. Gmm001

    Gmm001 Member

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    We have a 1930s house with solid floors and wooden floorboards. We have had ossues of an oily / bitumen smell in some areas of the house sometimes. On recently removing carpets in the hall and front room the smell was very noticeable both on the carpets/underlay and in the rooms. Further investigation seems to be timber floor boards 28mm thick(?) Laid directly onto a black thick layer of perhaps mastic asphalt. It is very hard where we can see it. Assuming it is MA is it normal for it still to be smelling after all this time?
    Second question is how to treat it. Has anyone experienced this? Carpets don't seem sensible as presume the same issue would return. Was thinking some sort of membrane over the floorboards then LVT flooring. Any thoughts from anyone who has come across this?
     
  2. dazlight

    dazlight Super Moderator

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    Yeah seen it in houses in Liverpool. The age of the house was 1950s.
    We used ardex NA screed and granno to sort it out
     
  3. Gmm001

    Gmm001 Member

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  4. Gmm001

    Gmm001 Member

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    Thanks Dazlight. Did you lift the timber or screed over the timber? We were hoping to just lay the lvt underlay that is taped at joints and walls over the timber boards and then water resistent click lvt.
     
  5. dazlight

    dazlight Super Moderator

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    We took all the timber out as it was rotten. can you post some pics
     
  6. Gmm001

    Gmm001 Member

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  7. Gmm001

    Gmm001 Member

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    Everything seems bone dry and no damp smells at all.
     
  8. merit

    merit Well-Known Member

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    I don’t Think LvT Over that timber is a good idea. Remove it and seal the bitumen and then build back up. Take a moisture reading of the floorboards, that will tell you how much damp is getting through the bitumen. Should also be tested for asbestos. No wonder it had a carpet over it
     
  9. merit

    merit Well-Known Member

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    Are the floorboards flat or cupped/showing ridges
     
  10. Gmm001

    Gmm001 Member

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    Floorboards are flat and no obvious signs of moisture anywhere.
     
  11. merit

    merit Well-Known Member

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    Yeah. I think the big obvious sign is that slab of concrete that’s pasted with bitumen. We see a lot of old houses with suspended floorboards and they read around 20% moisture. That’s too high for LvT and will rot that timber eventually if it’s covered.
     
  12. Gmm001

    Gmm001 Member

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    Thanks for the views. It looks much more like mastic asphalt as a thick layer dpm (20mm? 30mm?) than a bitumen paint over a slab. Contacted the mastic asphalt council with photos too and they thought it looked like MA but couldn't understand why still an odour. Having had the varpets up for a week now there is no pbvious smell unless you put your nose right to the boards. Puzzling one.
     
  13. merit

    merit Well-Known Member

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    How are the boards fixed to the floor?
     
  14. Gmm001

    Gmm001 Member

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    As far as i can tell loose laid but diagonal nailed to each other. Very tightly fitted together.
     
  15. merit

    merit Well-Known Member

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    Well you defiantly can’t fit lvt over that if it’s floating. If the nails have damaged the subfloor it will effectively be a damaged dpm too. It’s all gotta go. Only place for that subfloor is a skip or a museum.
     
  16. Rugmunching

    Rugmunching Well-Known Member

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    No way would I risk fitting anything other than another carpet over that. That's a disaster waiting to happen soon as that's covered with an LVT
     
  17. Gmm001

    Gmm001 Member

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    Thanks gor the views and discussion. Is tge issue likely to be damp and rot with an lvt hence the carpet suggestion?
     
  18. Rugmunching

    Rugmunching Well-Known Member

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    The screed under the lvt could blow if you was to go that root
     
  19. Gmm001

    Gmm001 Member

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    What do you mean by "blow", asduming it's madtic asphalt? Thanks
     
  20. Gmm001

    Gmm001 Member

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    Sorry for poor typing. What do you mean by "blow" assuming it's mastic asphalt. Is what i meant to type.
     

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