The Brew Cabin

Posted: **Tue Jun 29, 2010 9:52 pm**

Hi, I have registered here in the hope of some expert advice.

I am extending an existing patio in my new back garden. I realise from reading on the internet that I should try to slope the new 600mm x 600mm slabs away from the house so water drains into the garden, but I am trying to line up with existing slabs that are close to the house in two rows, and existing slabs in an eating area further away.

The problem is that if I slope the new slabs as I know I should, they won't line up neatly with those that already exist.

I then noticed that I have a 15cm channel of chippings all around the house. Is this some kind of soak away system? It is of course under the Damp Course, and has drains in it for the kitchen sink and dishwasher.

That set me thinking that maybe I am being too over cautious? If this is a soakaway drainage system, then even if water does run off towards the house, it will be caught by this 15cm of chippings and soak away. I was also thinking that I would just use the tonnes of chippings I have lying around to put between the slabs instead of mortar, then any water can drain away between the slabs, surely?

I have enclosed some pics to show you what I am going on about. Any advice will be most appreciated. I am new to this garden landscaping lark!

Thanks.

Posted: **Thu Jul 08, 2010 8:53 pm**

Anyone? Nope? 121 viewings and not one piece of advice?

Posted: **Thu Jul 08, 2010 9:20 pm**

looking at its position 150 below damp it looks more likely to me that they didn't want the hassle of cutting in around all the drains and pipes so simple did 2 straight rows of paving 100mm off the wall and then threw some decretive gravel to make good.

as for your question you can under cut the edge on the new sloped paving that abuts upto the existing edge allowing a normal width joint and a gentle tranistion to your fall of some where around 1:60 mark for the new patio.

its that or take up the existing and relay it all as a new project.

Edited By GB_Groundworks on 1278620489

Posted: **Thu Jul 08, 2010 9:48 pm**

sorry nick ,
I had the temerity to go on holiday for a week
I can assure you it wont happen again :;):
TBH the slabs you already have do not look the finest
i would be tempted to take them up then asses your levels
as Giles correctly says that shingle is just laziness on the part of the original contractor
if possible you dont want water falling towards the house
its asking for trouble
regards LLL

Posted: **Fri Jul 09, 2010 4:29 am**

The water from your dishwasher has to go into the gully Nick, not the shingle.

Posted: **Fri Jul 09, 2010 7:16 am**

when i replied could only see 1 photo, don't bother undercutting thought you had more fall than that

rip the old ones up good jet wash then relay to a string line so you get a nice straight fall to the grass

off to earn now but i'll be back to answer more questions after a 12 hour day haha

The Brew Cabin

Advice on patio extension drainage please! - Complete diy newcomer!