webuser_646101043

Damp proof (membrane) for floorboards

HU-646101043
5 years ago

Hi smart guys,


I am totally innocent for interior design and DIY. I want to change the carpet to solid wood flooring for my bedroom.


Currently, there are floorboards below the carpet, and I think I should lay the solid wood flooring above the floorboards after I remove the carpet.


Unfortunately, I found there are damps on the floorboards. Some of the floorboards also need to be replaced. I searched online and found something called 'damp proof membrane'. However, lots of discussions saying that this kind of 'damp proof membrane' is suitable for damp proofing concrete floors above ground, but NOT for the floorboards.


I also checked the situation below the floorboards, there are quite a lot of empty space there and I don't think I should remove the floorboards and put on the concrete.


So my question is: what is the best option for me now? I want to keep the underlying floorboards (replacing some broken ones). Before I put on the solid wood flooring, which kind of damp proof (membrane) I should apply? Please give me a link to the product if possible. Any other suggestions please let me know. Thanks very much for your help.



A.

Comments (5)

  • obobble
    5 years ago
    Are the boards which need replacing rotten? Is that due to the damp? You need to evaluate the condition of the joists - the beams supporting the floorboards - before proceeding to see if any of them need replacing too. You also need to work out what the damp was caused by and remedy it or you will end up with rotten joists everywhere. If it is a suspended floor there should be airbricks in the walls beneath it for ventilation. Blocked air bricks is a common cause of damp and rotten boards. Another potential cause is if the ground outside has ended up higher than the DPC in the walls ( if there is one).
  • HU-646101043
    Original Author
    5 years ago

    Thanks for your suggestions. The bedroom is on the ground floor and currently the floorboards are sitting on the joists directly (I will double check if any insulation or anti-damp been done before). There are one or two (about 1 squre meters) of the floorboards are rotten. I will check the ventilation to see if blocked and if any other joinsts got rotten too. To check the joinsts, should I take off the all the floorboards (good ones) or is there any other method to check them? Currently, they are nailed directly to joists. Thanks.


  • PRO
    Italian Design Ltd
    5 years ago

    Firstly check where dump comes from. No point in replacing the floorboards if then there is too much moisture. Replace all damaged floorboards and make sure joists are sound and stable. Then you can add a damp proof membrane over the pine floorboards. Then you can add the underlay and the floating hardwood flooring on top.

    Solid wood flooring is the worst option in areas where there is moisture. We strongly recommend quality engineered flooring instead.


    This is a rather complex job if done properly. The installation of the damp proof membrane is crucial obviously and to do a good job you should remove the skirting boards.


    damp proof membranes are available from may retailers https://www.screwfix.com/p/capital-valley-plastics-ltd-damp-proof-membrane-black-1000ga-4-x-25m/88322 and all have more or less the same specs.


    The DPM is indeed required to damp proof anything above the structural floor. There is nothing you can do on the structural pine board other than making sure there is no water leakage and there is good ventilation. hope this helps

  • obobble
    5 years ago
    Depends on how much space there is under the joists. If a Victorian or older house there might be enough crawl space to get underneath. I think you need proper professional advice on this - but not from a company that sells damp proof courses!
  • PRO
    U.studios
    5 years ago

    Considering you're upstairs, replace all the floorboards, put down pine floorboards perpendicular to the joists, cover them in the damp proof flooring membrane or foam (you can get some with a adhesive side so you can attach the hardwood floorboards easier (perpendicular to the pine floorboards)

Ireland
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