The Brew Cabin

Posted: **Thu Jun 30, 2016 7:44 pm**

Hi

Just wondering if I need to put in drainage for the indian sandstone patio I'm planning.

The patio in the main will be laid between my house and a 1100mm high retaining wall. The space between house and wall is only 2300mm.

Currently there is no drainage, the patio at the minute is old council slabs with an area that has red chips.

There is a fall at the minute across the 11 metre length heading into my neighbours property, which is way lower than mine and also much lower than the house at the other side of them. There is also a fall from my house going back to the retaining wall.

The wall is not in the best of condition but I don't currently have the funds to replace it, must be 60 years old, I plan to repoint it and replace a few broken bricks and paint it.

There is a drain round the side of my house that's from the bathroom stack.

I plan to make my new patio the same height as the existing so happy to have fall's in both directions but thought I should ask if that will be ok or if I really do require putting in some drains.

Thanks

Posted: **Fri Jul 01, 2016 12:56 pm**

Yes: you need drainage.

Posted: **Fri Jul 01, 2016 5:06 pm**

Thanks for the reply, I know it was likely a silly question so sorry for that.

Today I looked at some of my neighbours patios, none of them had drainage, which I know means they were likely laid wrong. Strangely my retaining wall doesn't have broken bricks/mortar at the bottom where it meets existing patio.

I guess I already know the answer to this but will ask anyway just to be sure. If when laying the patio I stopped 150mm from the wall and possibly the same at the house and backfilled the borders with chips that it wouldn't be sufficient to help let water drain away as below my paving is going to be my compacted type 1?

I guess most likely I will need to run linear channel drains the length of my retaining wall. Just so all my information is here, my finished height will be as existing so it ties in with slabs at side of house stairs etc and that height is 250mm below dpc and my fall will be away from the house towards retaining wall.

Posted: **Sat Jul 02, 2016 2:45 pm**

I don't like splash strips, the 150-200mm wide gap fiilled with gravel between paving and masonry. It's just somewhere for weeds to grow, a source of ammo for pesky kids, and, on the wrong substrate, they can't cope with heavy rainfall.

Many patios that might be interpreted as having no drainage probably have a fall and drain to earth, either a lawn or a garden bed, or something like that, which is all well and good as long as you can be sure the ground will be able to cope with the extra water beiung dumped onto it in one location (rather than being spread out over the area now covered with paving).

The great advantage of proper drainage is the knowledge that the SW will be dealt with, either being directed to a soakaway, to a local watercourse, or, as a last resort, to the existing SW system.

Posted: **Sat Jul 02, 2016 4:15 pm**

Thanks again, the soakaway is out really as my lawn starts at the top of the retaining wall, the patio area is quite sheltered by the retaining wall and 6 ft fence at either side but will be likely going with channel drains and just linking them to existing drainage. Just with such a narrow paved area the drains will take up some much needed space but better that than a flooded narrow area I guess

Posted: **Tue Jan 16, 2018 1:18 pm**

Looking for some advice. I am planning to lay a new patio approx 40m2 and my question is what sort of drainage would i require. There will be a small decorative wall built at the middle of the garden to seperate in two. The slabs will fall from the house towards the small wall and was wondering if i need drainage and if so what sort. I have no where to drain the water to and cant connect to any shores.Are there any other options for drainage

Posted: **Wed Jan 17, 2018 6:35 am**

Go to this page and click on soakaway link in top right hand panel.
read this

Posted: **Thu Jan 25, 2018 6:27 pm**

There's also a whole page devoted to the more commonly encountered methods of draining a patio or driveway here

The Brew Cabin

Patio drainage?