dry rot/ damp

Discussion in 'Builders' Talk' started by mikmac69, Nov 7, 2009.

  1. mikmac69

    mikmac69 New Member

    hi can anyone put me straight on this one? basically bought a terraced house and in their wisdom the previous owner/builder had a dpc injected and then re plastered straight on to the bare brick with bonding(no render mix) they then banged the skirting straight on,now several years later,its got severe dry rot! my questions are 1, now the plaster's off do i start again with the dpc,injection & render(or just render) 2, the webbing off the dry rot is all over the bare brick,how do i get rid of it? which treatment or will the re-render be enough?
  2. Mr GrimNasty

    Mr GrimNasty Active Member

    No expert, but you'll certainly need to ensure the infection is dead before you cover it up - you need a masonry biocide treatment.
  3. flippin heck

    flippin heck New Member

    There should be a gap between the bottom of the rendering and the finished floor level. If the original plaster went to the floor, then moisture could have bypassed the DPC.
    Personally, I would re-inject, render (with water proofing additive in the mix) and skim, because you do not know how effective the original injection treatment was. You can hire the injection equipment, but you have to consider the DPC guarantee which you may need if you sell the house on.
    If you have a suspended wooden floor, then you also need to inject below your joists.
  4. gordon bennett

    gordon bennett New Member

    You really need to make sure you eradicate this completely, dry rot can cause thousands of pounds worth of damage to your property,
    You need to remove all the affected plaster and then another 600mm past the last sign.
    Then the walls have to be brushed off using a wire brush to get rid of all the visible strands.
    If the skirting is affected then its possible that the wall plate and joist ends under the floor are also.
    The walls then have to be sterilized using a anti fungi solution i think you should get in the proffesionals i wouldnt try this as a do it your self remedy.
    When you replaster you should use a washed sand and cement render mix with a suitable waterproofer followed by a plaster finish coat.
    Bonding is not suitable for walls with previous damp problems.
    When you replace skirting give the backs a couple of coats of oil based primer.
    Check your guarantee you might have had treatment for dry rot previously and still might be under warrenty.
    Hope all this is helpfull if you need any more advice please ask.

  5. Welshmally

    Welshmally New Member

    Been there, done that, got the warranty. This really is a job for those that are experts in this field. It may actually cost less than you think, and is DEFINITELY worth the money for the peace of mind.
  6. 12benny

    12benny New Member

    A number of questions: why, if it's important, haven't you researched this topic? If you had, you would have supplied a number of details about the complaint, such as:
    q1 type of wall- composition, cavity, thickness.
    q2 type of floor
    q3 level of outside ground
    q4 any leaks/rainwater from gutter etc.
    q5 how do you know it's "dry-rot"?
    q6 how do you know it's bonding? not that it's relevant.
    q7 what ventilation is present?
    q8 is this the only location with "damp" in the property?

    As a matter of interest: 3S1C1L is a good render mix, skimmed with a remedial finish or board finish.
    Wash the wall with custom fungal chemicals and paste the back of any new skirting with custom "mayonnaise" treatment.
  7. gordon bennett

    gordon bennett New Member

    Hi Benny.
    lots of information there,i know exactly what you are talking about,but for someone who has just purchased his first house,hats quite a lot to take in.
    After reading some of these answers and the damage that DryRot can cause he will probably get a company in and not try to cover this up without treatment.
    yes i agree you have covered a lot of possible causes and these should be investigated further,Dry ROT doesn't happen overnight
    Not sure if you can purchase mayonnaise paste without belonging to a trade body,but i may be wrong.
    regards john
  8. mikmac69

    mikmac69 New Member

    hello all thanks for your help and advice, i'll certainly take it. sorry benny12 i wanted just to put a basic outline of the problem on to the forum but your points are noted for my next questions!! cheers again for all taking the time.
  9. jenros

    jenros New Member

    hi there,
    dry rot(or the correct word is called merrillius lycarmins)pretty sure this is not the correct spelling,but this is the latin word for it!!!! hope you lot are impressed by this!!!! i remembered this from my college days.
    the main cause of dry rot is from a lack of THROUGH ventilation,main areas are under stairs wooden suspended floors etc.as one of the replys said this needs an expert to have a look at for you,don't just think that it is a quick weekend job agree that is a fairly straight forward job ONLY when the correct diagnostic answer has been reached.
    when removing affected timber, the timber should be completely covered as not to allow the tiny spores to fall off when transporting it out of the building,these spores are minute particles that will fall off,most are unseen with the naked eye.all affective timber should be burned,as far away from your property as possibly.
    dry rot will travel up and through walls into adjacent rooms/ceilings trying to find other timber to infect.
    in an empty premises where the work is to start it is much easier to inspect,if you have a occupied house then you have a complete new ball game to contend with,ie,how do you know that the timber has not been affected from one room to another without exposing the plaster etc,and bearing in mind that more than likely one room is empty and furniture etc is now piled in the room you need to inspect,and that by hacking off a wall or whatever that you have get to, you have got to be very careful that you do not transfer any particles or spores which will then be in the room.
    hope this helps,and good luck
  10. ambient

    ambient New Member

    I would doubt you would need any specialist treatment, dry rot needs a source of dampness and a stable environment to survive, if you remove the source of dampness, and ensure the surrounding area is ventilated, the dry rot will die off, just make sure to check underneath the floorboards as if the wall is damp theres a good chance the floor joists will be as well, also make sure the airbricks are clear.

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