Drainage issues behind garage

gazdavtom · Post: # 110635Post **gazdavtom** Fri Aug 05, 2016 7:46 pm

Hi all,

I have an area measuring approx 9 foot by 8 inches that mostly sits between the rear of my garage and a dwarf wall in my back garden. During rainy weather it tends to fill up with water and is very slow to drain. The area also abuts the side of my house and the water sometimes rises as high as my DPC. I think part of the cause is the speed of the surface water run-off from the roof of my garage. Rather than meddle with this I was hoping for a more simple solution. The area in question consists of an approx 7 inch layer of soil followed by what appears to be a sand and gravel mixture. It also doesn't help that the surface level of the area is less than 150mm from the DPC. Someone suggested digging out the soil to a safe level and then topping with a layer of pea shingle. Is this right, what would you suggest?

Thanks in advance.

Post: # 110636Post **seanandruby** Fri Aug 05, 2016 8:43 pm

As always a photo or 3 would tell us more. Is there any drainage in there? Digging out soil and replacing with shingle is only a solution if the water drains away, not clay soil.

rxbren · Post: # 110637Post **rxbren** Fri Aug 05, 2016 8:54 pm

If there is a rainwater down pipe nearby run a linear drain in the gap and run to the underground drainage pipe from gutter down pioe

Post: # 110642Post **seanandruby** Sat Aug 06, 2016 6:47 am

...If there is a down pipe and water is from your garage roof then the pipe could be blocked and backing up if it's flooding the strip. So need more info.'

gazdavtom · Post: # 110654Post **gazdavtom** Sat Aug 06, 2016 12:17 pm

Drainage Issues

Use the above link to view some pics of the said area. Excuse the mess! I don't know if there is currently any drainage below ground. When I hit the sand and gravel it was fairly soild. There isn't any downpipes etc either. Hope this shines a better light on the problem.

Post: # 110656Post **seanandruby** Sat Aug 06, 2016 2:58 pm

Does the fall slope away from that wall? If it slopes awsy then why not do awsy with the wall it doesn't seem to be of any use. You could then fill in the trench, unless it compromises the dpm.

gazdavtom · Post: # 110657Post **gazdavtom** Sat Aug 06, 2016 6:37 pm

There isn't any fall away from the wall, but there is a slight crossfall towards the direction of the house. The patio is far from well laid and is also the topic of another post on this forum, see here

gazdavtom · Post: # 110658Post **gazdavtom** Sat Aug 06, 2016 6:48 pm

If it's any help, I have included some images of the patio area in the link. The flags sit about 140mm below the DPC.

Drainage Issues

Post: # 110684Post **Tony McC** Mon Aug 08, 2016 12:31 pm

If there *is* a layer or sand and gravel, you have the ideal site for a soakaway.