Damp Basement Conversion...

[LordMikeNot]

Evening all,
This issue has just thrown another curveball which has made me sign up to here to try and get some opinions.
I've got an old victorian terrace down in Portsmouth and looking to get the basement tanked and used as a suitable DRY storage space. Thought I had it sorted when a builder said no worries, we can tank it then dry wall it so you can put fixtures up etc etc...we have just had another builder round and said the complete opposite as the bricks have been painted with what he assumes is 'BlackJack DPM'. He said no matter what you do, it'll always be damp down there because of it. unless you spend ££££ to put in a drain with a pump...which he said is a VERY expensive way of doing it and advised against it.
So, I'm hoping there maybe a Damp Proof expert on here that may be able to clear the up! What I want to know is, can this BlackJack stuff be removed from the brick without costing £££ or is there another way to turn the damp dingy basement into a useable space?
Many thanks.

 

[vinn]

Did the first builder actually apply the Blackjack?

Have any of your new neighbour's managed the trick of getting a dry basement?

There's a whole range of variables that you might like to look up by searching on here - without knowing much more about the basement situation I'd find it difficult to advise you.

For a basement to be made perfectly dry, you often need a Rolls Royce tanking installation.

 

[LordMikeNot]

Hi Vinn,
Thanks for the prompt reply. The first builder didn't apply the blackjack. It's looks like it's been there for well over a decade. Possibly two. Other neighbours have got their basements tanked, but I don't think their walls were/are covered in this black stuff. The latest builder basically said that with blackjack, it doesn't allow the walls to breath and as the floor is where the damp is penetrating, the dampness will always be present???

 

[vinn]

The Blackjack is almost irrelevant without a context of info variables and pics.
If you want to inform yourself then perhaps do as I suggested, and research the matter.

 

[tomfe]

There is plenty of reading to do on basement conversions. Black stuff on the walls will make little difference if they are tanked with a sump etc.

 

[^woody^]

The latest builder basically said that with blackjack, it doesn't allow the walls to breath

Lol. In ground full of water, the last thing you want is walls "breathing".

Blackjack is a waterproofer. That is what you need in a basement.

Basement waterproofing requires that the wall and floor be lined with a water proof material. This can be either on the structural walls and floor, or on an inner lining which then has a cavity behind it from which water that enters is drained and pumped out.

 

[Ian H]

You could dig a sump now and see if it fills with water, you might not need any £££££ drains, just the ££ pump

 

[^woody^]

You could dig a sump now and see if it fills with water, you might not need any £££££ drains, just the ££ pump

Or wait until January when the water table is higher?

 

[Ian H]

Or wait until January when the water table is higher?

That's a good idea. You could get a pump in the January Sales too.