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Damp Proofing

What to do next in my cellar

hi and thank-you in advance

i had a big problem with damp in my cellar. the floor was wet and the external walls all had rising damp with the plaster all flaking off. the cellar is below ground level.

my cellar has recently had the floor tanked. i am not a Builder and do not understand the words to use so i will explain what i mean.

the floor got dug down a foot and then a thick black plastic type sheet was placed and then concert was put on top, this was done throughout the cellar.

after the builder finished the floor he started on the walls. he said he is dry lining the walls. from what i could see the builder used dot and dab and stuck the plaster boards on. then he plastered the walls.
on a later date he drilled holes at the bottom of the walls a few inches higher than the ground. now the builder has disappeared and we have damp coming up the external walls again. the builder was suppose to inject something into the holes he drilled, he said he will inject the holes but the builder is nowhere to be found now.

i was wondering if anyone knows what i need to inject into these holes and if its something i can do instead of calling another builder out.

any suggestions will help

thank you for your help.

6 Answers from MyBuilder Damp Proofing Specialists

Best Answer

hi the black plastic sheet may be a cavity drain membrane, drilled holes for dpc not good in a basement,should not have dot and dab in basement, may need a sum pump


Answered 3rd Feb 2012

this job has not been carried out correctly,you cant dryline a damp cellar and call it tanking ,proper tanking of basements is more involved and can be expensive hence this happens and people go for cheap imitations ,all this needs taken off to do properly ,too much to go into detail ,get a proper builder/basement conversion company to come round and advise properly ,but my guess is you already got quotes of these companies and they were probably 4 times more expensive than the quote you accepted ,now you have found out why ,there are no cheap bargains in building


Answered 1st Feb 2012

The holes your builder drilled would have been for an injected damp course.
The walls in the basement should not have been dot & dab, but a tanking system used.

You would have been better of using a company that specialises in basement tanking, they would have gauranteed their work.


Answered 1st Feb 2012

probably need to rip up the concrete and add a sumo pump as well if its so wet.


Answered 2nd Feb 2012

I agree with substructure.

You've been 'cowboyed' I'm afraid to say. Get in touch with cowboy builders... I'm serious they may put it right for you as they'll get an episode for their hit TV series out of it.

Drill and inject systems make a horizontal damp course to stop water coming up from ground level. The problem is you're in a basement so the water just comes above the drilling line. You are below ground level so drilling is absoloutley irrelevant. It's appaling what has happened here. I do hope you haven't paid in advance for this?? contact the office of fair trading etc, some kind of ombudsman - and get this person banned from the market place. They are giving us a bad name.

Sump and pump / membrane system - possibly tanking if no history of major flooding. You need to contact FMB or Sovereign Chemicals. They will reccommend a local 'approved' contractor.

You would expect to pay at least £3,000-£4,000 for the walls alone here (assuming a room no more than 4x4 meters). If there is a problem with the floor then that needs rectifying before the floor surface can be tanked. And if the floor is being tanked it would then need a substantial covering like tiles for example - to protect the tanking.

If this guy can't be traced every penny is lost. Nothing is of use that has been done. Nobody can give a guarantee because the floor is fundamental to a tanking job, and it has been done by a cowboy.

My sympathies.

And a message to all (as my associate above so aptly states: THERE ARE NO BARGAINS IN BUILDING.

A good builder doens't need to offer knock down prices - so why would they? They are ususally in a reasonable amount of demand so can expect to charge the indsutry standard rates. They don't need advance payment as their cash flow should be in order if they are running a successful business.

Perhaps 50% paid upon arrival of materials (all materials) and the job is well underway. This shouldn't be a problem if they are reputable, you can get references, they are certified with relevant trading bodies etc etc.


Answered 20th Feb 2012

Eek. You got caught by a bodger. Did you pick the cheapest quote? Probably needs striping out and doing properly, your next worry is what else he may have done that you cant see...


Answered 1st Feb 2012

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