house has a cellar that is cut from hillside - water enters

by **paul1** » Mon Apr 30, 2007 6:46 pm

My house is on hillside - built in the mid 1800's. The cellar has been cut out from the fairly soft porous rock, below the street level - much like a well, in fact. When the weather is very wet, the water level in the surrounding rock rises - and water starts to seep out of the floor of the cellar - fortunately, there's a continuous 'gutter' around the circumference of the cellar floor. The water flows horizontally across the floor, into the gutter, down into a grid, and away from the house - quite adequately. What I'd like to do, is to create a dry floor, by building up the floor level by an inch or two, but have a cavity underneath for any seeping water to drain horizontally away to the 'gutter'. Presumably, laying a Cavity Drainage Membrane and laying a concrete floor on top of this, is my best option? Who stocks CDM? - it still seems to be quite a 'specialist' product. Thanks.

by **thedoctor** » Mon Apr 30, 2007 7:14 pm

See the projects section and look at underground waterproofing

by **tucny** » Fri May 04, 2007 9:42 pm

A local damp proofing specialist should be able to supply you with cdm. However be aware that all is not simple when managing water entry and there may be building regs etc that you must comply with depending on how you intend to acheive the dry floor.

by **paul1** » Sun May 06, 2007 1:01 pm

Ok, thanks for the replies.

by **harbyma** » Wed Jun 13, 2007 6:46 pm

Hi, I have just done the same with my basement. The products were sourced from chemical building products. To meet bs 8102 you will need to use cdm on the walls with drainage channels to a sump pump or outside soakaway. CDM cam also be used on the floor but to mmet present building regulations will then need a covering of insulation, on top of which you can use 18mm t&g chipboard. Hope this helps.

by **gilly** » Thu Jul 26, 2007 8:41 pm

[quote="harbyma"]Hi, I have just done the same with my basement. The products were sourced from chemical building products. To meet bs 8102 you will need to use cdm on the walls with drainage channels to a sump pump or outside soakaway. CDM cam also be used on the floor but to mmet present building regulations will then need a covering of insulation, on top of which you can use 18mm t&g chipboard. Hope this helps.

[/quote] Hi, I am very intersted in CDM for a badly constructed conservatory. did you carry out work yourself or get in specialists. how does a sump pump work?

Regards, Desperate