The Brew Cabin

Posted: **Wed Dec 10, 2008 12:04 pm**

Hi folks, I have an issue that I require some advice on. We recently moved into a house with a drive that slopes from the street up to the house (gentle incline). As a result of the driveway incline, the level of the ground is level with the DPC at the back of the house for approx 1.5m on the incline.

To complicate matters, the previous owners decided to lay a series of patio slabs (approx 2 x 2m area) that raise the outside ground level further at the rear of the property which means the outside ground level exceeds the level of the DPC.

There is also a new conservatory at the rear of the property and the DPC of the conservatory is only 1 brick above the patio slabs.

I hope that all makes sense â€“ I have posted some pics to help visualise the problem.

I am concerned about the DPC being breached and need some advice on the best course of action. I have read the site and believe I need to lower the external ground level to ensure the DPC can do its job properly. I could simply remove the patio slabs to achieve this. Is this the best approach or do I need to do anything else? Any advice would be greatly appreciated.

Thanks.

Posted: **Wed Dec 10, 2008 5:08 pm**

is your dpc not at floor level because your geen line is two courses below floor level as you look at the back corner of original house so only flags and concrete up to them is too high

Posted: **Wed Dec 10, 2008 6:35 pm**

Thanks for the reply ambient. I agree with what you say but shouldn't the green line (i.e. the DPC) always be 150mm above ground level, therefore, the ground level at the rear of the property and the incline up the drive needs lowering to suit the 150mm rule? I guess other people must have this issue as lots of drives slope upwards from the street.

Posted: **Wed Dec 10, 2008 10:01 pm**

they have put the dpc at that level for the floor joists to sit on,probably 4 by 2's with 22 mm floor boards
but the slabs are too high
LLL

Posted: **Thu Dec 11, 2008 7:30 am**

Thanks LLL. I will look into removing the slabs ASAP. Does the driveway need any work to make sure the DPC is higher than the driveway level? Thanks again.

Posted: **Thu Dec 11, 2008 12:11 pm**

DPC level is NOT determined by height above ground level. It should be t'other road 'round: ground level should be determined by DPC level, and established at not less than 150mm below DPC, except at thresholds where level access is required (Building Regs Part M)

Posted: **Thu Dec 11, 2008 12:23 pm**

Thanks Tony McC. Given the 150mm rule, I need to lower the level of my drive to compley with the 150mm distance. Not entriely sure how to tackle this as it seems like a lot of work and probably quite costly - any suggestions?. Thanks for your input.

Posted: **Thu Dec 11, 2008 12:36 pm**

A dry area channel seems easiest

Posted: **Thu Dec 11, 2008 5:29 pm**

in modern houses the dpc is normally at finished floor level,looks like you are just unlucky kevin
it will save you money in the long run mate,doing it right
LLL

Posted: **Thu Dec 11, 2008 7:23 pm**

Thanks for the advice guys. I think the best course of action is to remove the slabs at the rear of the property and then create a dry channel down the side of the house... unless anyone else has any ideas?????

Posted: **Thu Dec 11, 2008 9:55 pm**

you could lift your house up then dpc would be 150 above ground level haha, sorry for the sarcastic answer in a silly mood :laugh:

Posted: **Fri Dec 12, 2008 6:01 pm**

Your second picture that shows a close up of a down pipe at the corner of the house appears to show the DPC stepping up a course. I'm looking at the line indicated by your green string and then at the top of the last perp joint and the bed above and to the left of it. They seem to have the same content that differs from the rest of the mortar joints. Just a thought i had when looking at the photo. Nick.

Posted: **Fri Dec 12, 2008 6:38 pm**

Thanks for your input Nick65. I see what you mean! I will look into it tomorrow when there is more light. Thanks again.

The Brew Cabin

Ground level & dpc - Ground level & dpc