The Brew Cabin

Posted: **Wed Feb 07, 2018 3:13 pm**

Hi
I've recently had a patio laid. I have read your advice in respect of DPCs which is useful. From what you say I think what has been done is just about acceptable as there is a step which leads to a short area of clearance of less than 150mm but as the steps joins two walls at the back and to the right - it is in a corner - I wondered if your advice would be different. At the back of the step the top of the step is level with the DPC but there is the overhang of the door frame over it. To the right of the step from the corner the top of the step is level with the DPC in the corner but falls away over an approx. 60cm distance to around 30mm below the DPC and then at the end of the step the level of the patio is about 75mm below the DPC and falls away to 150mm over 2-3 feet.
Thanks

Posted: **Wed Feb 07, 2018 5:58 pm**

sounds ok
the 150 rule is generally applied to the main area of the patio
it also depends where you live
the north west is much wetter than the south east
steps by their very nature always tend to encroach
LLL

Posted: **Thu Feb 08, 2018 9:17 am**

We have to temper the "150 below" rule when it comes to steps, for obvious reasons. There are various ways of dealing with steps - some will incorporate a slot drain; some (for reasons unknown) slip a piecve of DPC vertically between step and masonry; some rely on a generous fall away from the masonry - and it's usually best to choose the strategy best suited to the actual job. It may be a slot drain on one job, and fall alone on the next.

Generally speaking, fall alone is often the best option.

Posted: **Thu Feb 08, 2018 9:28 am**

Thanks for the replies. Do you think the fall away mentioned sounds sufficient?

Posted: **Fri Feb 09, 2018 9:21 am**

30mm over 60cm = 30 in 600 = 1:20, so tha;'s fine.

75mm over 900mm = 1:12, so that's even better!

Posted: **Fri Feb 09, 2018 10:36 am**

Thanks again.

The Brew Cabin

Dpc - Dpc clearance