PVCu patio sliding doors and DPC, how low can you go?

1 Sep 2020
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United Kingdom
Hi All,

We have had someone round to check an opening for PVCu doors and he recommended we take the course of bricks down a level. The builder has responded that he can’t go down a course of bricks as this would mean he is below the damp course of the building. However, this means there is a (small) step up to the bring from the screed to the brick before the doors would be installed making the step over even higher. If we took it down a brick the step over would be less of a trip hazard, so we would like to take it down a layer if possible.

Taking down a course of bricks would still leave a layer of brick and the DPC under the insulation and screed would still be below that...

Where is the damp course on a victorian build? I am wondering if this is for Building Control, or if the builder trying to avoid work? We are happy to take the course down ourselves with an SDS drill! Alternatively, is there a way to install half-height bricks to bring it flush with the screed level?

There is also a gap that has been left between the screed and the brick wall that the doors will sit on.

Any help/advice would be great.


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A damp proof course can step down below a doorway.

Is that airbrick now redundant?
Thanks Notch7! So it sounds like the builder is trying to avoid the extra faff?
From what I can see, even with one course of bricks lower, the bottom of the door should sit above the DCM under the new floor anyway. Does a building have a damp course that is different from the black DPM that is in the picture that he is talking about maybe? It's a 1981 victorian house but this part is definately pre-then and was probably outside originally.

That is actually a new airbrick, and another area I need to find out about!
The pipes stop short and we are waiting to get an explanation from the builder. He laid DPM, then insulation with air pipes running across to the suspended floor further in the house. Then subcontracted the screeder. The screeder has got screed over the pipes, so I am assuming the builder will chip that back and somehow extend/connect them up to the airbrick. here are three pipes but you will see that only 1.5 is clear of screed. The reason why we didn't do it ourselves was because we were unsure of how to do the ventilation right, and I am anxious that this may have been done wrong now anyway!!


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