Damp Proof Course

[Goksly]

Hello!
Ok firstly new build alert... so please keep that in mind...

So I'm having my garden redone so I'm having some people out giving quotes etc. Two people have commented that my damp proof course is pretty much ground level so they're adding £500 to run a french drain around the garden side of the property. Is there any legislation around this? Looking online there seems to be a suggestion this should be 6" off the ground but it's pretty level. Any help and advice appreciated.

 

[thezappa]

If it’s a new build contact the developer and tell them to get the site manager round. Dpc should be 2 brick courses over finished floor level. If it’s level then there is something wrong and the ground workers haven’t done the setting out correctly.
This should be picked up during warranty inspections but a lot gets missed in these things so don’t let them fob you off by saying “well NHBC (or whoever) has signed it off”.

 

[Goksly]

So do I have any recourse? Looking online they say 150mm which is much less than two bricks? I want to know what I can go back to them with.

 

[thezappa]

Most bricks are 65mm thick, plus 10mm mortar joint x2 that’s 150mm.
You do have recourse because it isn’t built properly (if the dpc is indeed at ground level).
Contact the builder and ask them to visit.
Can you see a thin black line in the mortar at any point?

 

[Goksly]

I'll take a picture tomorrow when I'm back home... Definitely ground level

 

[Goksly]

So here are the pictures... Really hard to see but it's pretty much flush with the ground in my eyes

 

[fastwunz]

The second picture would suggest the patio is level with the DPC.

if that’s the case then you will get bridging off the DPC and it’s all kinds of wrongly built.

You need to walk around the property and see if you can see any black plastic sticking out of the mortar beds - often you see it around openings in particularly or at the junctions of two walls I.e. an external corner - that will tell your definitively at what level your DPC is at

 

[DB_SamX]

You have at least one legislative recourse - failure to comply with Building Regulations Part C - link below. Diagrams 5, 8 and 9 all show the requirement for the DPC to be ground level + 150mm. I am no architect, only a mere structural engineer, so I cannot guarantee there is a workaround somewhere in the regs, but in 15 years +, I have never worked on a job where a DPC has been at ground level - usually it's typical to just provide the 150mm (approx).

https://www.gov.uk/government/publi...contaminates-and-moisture-approved-document-c

Your second recouse is your home warranty provider. As you've said it is a new build, most, if not all of them have a warranty provider such as NHBC, Premier, etc, which is valid for 10-12 years from build completion. Usually warranty providers use Building Regulations as their minimum design requirement, but sometime they will require above and beyond. They also issue their own design documents, and I reckon if I were to look up the same detail for DPCs for NHBC, or Premier, I would find at least the same as Building Regsulations' requirements.

My opinion is that your warranty provider is the easiest contant for resolving this. I don't really know how you go about finding out and contacting whoever approved the build (your local council Building Control Officer or a a private Approve Inspector).

 

[norm]

So here are the pictures... Really hard to see but it's pretty much flush with the ground in my eyes

The 3rd pic is a bit concerning, the whitish deposits on the brickwork is called efflorescence which forms when water is present.