DPC Height doesn't match main house

[Fieldmouse]

Hi,

go easy on a lady!

looking at our new extension walls, it looks like the DPC on the inner wall is higher than the original house. The floor joists in original house are sat on a wall, and I think an old DPC material... this level is lower than the DPC hanging from the walls in the new extension. I would assume that the level the joists are set at would be the DPC level.... you wouldn't have a damp layer above the floor joists... as joists sit in the wall too....?

if so, how much of an issue is this at the point where they (should) meet? should building control have spotted this? if it is wrong, are BC somehow liable?

any advice appreciated... I am not an expert... or even the start of being an expert...

kind thanks,

J

 

[Ivor Windybottom]

So... is the new extension a solid floor at the same height as the existing suspended floor?

It should be under the joists in the existing house, and at floor level within the extension.

Are you asking what it should look like where the high DPM meets the lower DPC?

Photos would be very useful.

 

[Fieldmouse]

So... is the new extension a solid floor at the same height as the existing suspended floor?

It should be under the joists in the existing house, and at floor level within the extension.

Are you asking what it should look like where the high DPM meets the lower DPC?

Photos would be very useful.

Hi. Finished floor screed will be at same height at floor in house. Does this picture help?

 

[Ivor Windybottom]

What's the question?

They should be at different heights as they're different floor typees, but the cavity of the existing house should protect the timber floor, as it always has.

 

[Fieldmouse]

Question is. Is DPC in extension too high as it seems DPC in house is lower, under joist level.

The house doesnt have a cavity, solid wall

 

[noseall]

Question is. Is DPC in extension too high as it seems DPC in house is lower, under joist level.

The house doesnt have a cavity, solid wall

The new DPC is at the correct height

 

[^woody^]

The DPC for a timber floor is typically lower than the floor surface, but with a concrete floor it is typically level with the surface.

It's important that the two meet and overlap so that moisture can't get up past the two where the floors meet. It requires a suitable detail.

Likewise, the floor DPM should be properly detailed at the junction of the two floors

 

[Fieldmouse]

The DPC for a timber floor is typically lower than the floor surface, but with a concrete floor it is typically level with the surface.

It's important that the two meet and overlap so that moisture can't get up past the two where the floors meet. It requires a suitable detail.

Likewise, the floor DPM should be properly detailed at the junction of the two floors

Ok great thanks. This is the strange bit.... as DPC set at expected finished screed height.... which is about 12cm higher than the level that joists are sat on.... but you can see in picture that the new DPC hangs out of new wall at the point it meets the original wall.... that point is obvs about the 12cm higher than the original DPC..... so there is no join.... Should the 'walk-off-the-job' builder have joined them vertically?