Internal concrete floor above DPC

[Dempsss]

Hello,

We have recently bought a house and have had a damp specialist out to check there isn't any major damp issues.

The house is early 1900 terrace.

The damp survey found that the internal concrete floor in the kitchen and dining room is above the external dpc. They have recommended digging up concrete floor and lowering.

The lower walls in dining room had mold and peeling wallpaper when we moved in. The tiles in the dining room floor, currently underneath carpet, also have damp wave marks on them.

I just wanted to double check whether this is legitimate issue seen in these houses and if the only option is to relay the whole floor?

Any help and advice would be much appreciated.

Thank you

 

[JohnD]

A 1900 house commonly has a leaking water pipe buried under the floor.

Have you got a water meter?

What is your water supply pipe made of? Lead or iron?

Draw a sketch plan of your house. Indicate the wet areas. Mark on it the position of downpipes, waste pipes, soil pipes, gullies, drains and manholes.

Mark on it the position of the external stopcock (probably where the front gate used to be when the house was built) and the internal stopcock (probably where the kitchen sink used to be when the house was built). The supply pipe almost invariably runs in a straight line between them.

Post this plan on here for us.

 

[JohnD]

P.s.

Do not allow anyone who sells silicone injections into your house.

 

[Notch7]

The damp survey found that the internal concrete floor in the kitchen and dining room is above the external dpc.

that is irrelevant.

what is important is whether the internal concrete (screed?) comes above the internal DPC level + whether the plaster runs down to the floor or stops with a gap behind the skirting.

if the house walls have a cavity, what level is the concrete fill inside.

They have recommended digging up concrete floor and lowering

You need to find out establish the problem first.

just wanted to double check whether this is legitimate issue seen in these houses and if the only option is to relay the whole floor?

There’s often damp issues in old houses caused by a lack of damp arrangements protecting the inside masonry from damp.

but you need to find the cause before doing work.

by the way, the solid floor will have no insulation so if you do decide to redo, you will neeed to dig down enough to put back: type 1 hard core, sand blinding, DPM, concrete slab, insulation probably 70mm or more and screed, which is around 350mm

the thermal element will need building control approval.

on the plus side it would have a real benefit in terms of warmth.

 

[JohnD]

The house is early 1900 terrace.

I think a cavity wall is unlikely.