The Brew Cabin

Posted: **Mon Mar 04, 2019 10:23 pm**

Hi
My question is to do with the alternative solutions as described on the Damp proof Course page DPC.
One of the alternative solutions talks about a linear drain being installed 75mm below the DPC. I am wondering where this is documented into any regulations that the ground to DPC can be 75mm with a linear drain instead of it being 150mm? Or, is this based on experience that this is an acceptable compromise?

We have had our driveway done and I am writing a letter to complain about the height of the ground to the DPC at the front of the house. I mentioned it to him when he graded the hardcore and sand up across the front of the house to be level with the DPC, but he assured me it was fine as he would tilt the block away from the house and continued to complete the drive. I have now come across this site which tells me it should be 150mm below the DPC and that I was right to be concerned.

Thanks

Posted: **Tue Mar 05, 2019 9:26 am**

It isn't documented anywhere. It is left to the discretion of Building Control, who, in most cases (but not all) will accept the invert of the channel as the "ground level" rather than the top of the grating.

I've been using this method for over 30 years and only once as it ever been refused, and that was by a right power-mad little git after I'd made the mistake of proving him wrong about the required width of regulating brickwork for adoptable manholes.

However, the method should oonly ever be used when there really is no sensible alternative. It is NOT acceptable when it saves on a bit of digging-out or when the installer just can't be arsed. The onus is on the installer to explain why it was not possible to comply with the 150mm below DPC requirement of the Building Regs.

Posted: **Wed Mar 06, 2019 6:41 pm**

generally BCOs will accept this when there is no other realistic option,some of them do live in the real world and would rather a workaround that a flat out botch
generally 75 mm to a linear drain has always been accepted,but if in doubt ask your BCO
LLL

Posted: **Sun Mar 10, 2019 11:34 am**

sh2515, Thanks to the others who have added their information. This set me back in 2004 to put my rear patio right and when I installed the front drive made sure i followed the 150mm depth. As has been mentioned though you can get away with less, the back of the house was not so deep and had a little damp. I am sure that doing it right helped it dry out.
Regarding your new drive, have you had a look when it is raining or water is run over the drive how it falls. The regulations are to ensure that the water runs away. Have you got eves of the roof that protect rain from the dpc? Hope fully you can use the information to decide what the outcome should be.

The Brew Cabin

Ground to dpc alternative solutions