Should Internal Walls Have a DPC?

Question

Hi allA little over 5 years ago I bought a 1970s (dump) house and discovered a water leak in buried piping (concrete ground floors).This has resulted in a significant number of rotted skirtings and door frame bottoms.Also, at each doorway threshold, the floor screed has blown.Digging down below floor level and investigating the construction detail yesterday I discovered:there doesn't appear to be any dpc to internal wallthe dpm below the concrete floor slab comes vertically up to floor level at the edge of the slab alongside the internal brick wall IYSWIM so the internal wall has plastic membrane either side of it from just-below-floor-level to the underside of the slabAs a result, threshold bricks are damp, have lifted/swollen and have broken away the floor screed.Phil

The Natural Philosopher · Accepted Answer

Naughty!There SHOULD be a DPC BELOW floor level at around the base level of the slab.If there isn't..and is an issue, inject teh bastards

Lobster · Answer

What, the errant builders you mean?David

The Natural Philosopher · Answer

Not a bad idea.

mail · Answer

PhilAnswer is "yes" - in the mortar.If you DIY use a silane product such as Dryzone as per instructionsYou "may" have to replaster some but in such a young house one wouldhope not - suck it and see?ChrisPS I know what a Sculler is - what is a Scullster?

TheScullster · Answer

wroteThanks to allFrom my investigation, I believe that the damp is residual rather than active IYSWIM.When we moved into the place there was a visible area of damp at top-of-slab level (albeit close to the leak site), so I would expect the sub-base of the house in general to have got pretty saturated.I suspect (and am hopeful) that damp we are now seeing is evaporation of this residual water through and around the slab.The plastic tiling applied to the entire ground floor will have trapped moisture in the slab very effectively (this tiling has all been removed).theScullster is nothing more than a nickname based on the word meaning to row.Phil

Lobster · Answer

Dunno, and what's a Lobber?RegardsLobster

Should Internal Walls Have a DPC?

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