The Brew Cabin

Posted: **Tue Apr 03, 2012 10:21 pm**

I'm replacing a domestic single garage for a larger one and having the drive block paved. I want to get the drainage sorted whilst i'm at it. The present garage has a linear drain across the entrance but having lifted the grills a time or two to clear out leaves etc i discovered the channel is not connected to anything. I assume any water entering simply seeps away past the end caps - although it doesnt manage to cope with anything more than an average shower before filling and overflowing.

I dont want a nice new garage spoiling by being flooded like the old one. Hence i would like to connect up the linear channels to the drains in the way shown on the Aco Drive Drain Installation Study elsewhere on this site.

Although not in the trade, i was feeling quite adventurous i thought i might like to have a go but seem to have come unstuck before i've struck a spade.

The problem is i don't know where I can connect the linear drain to? My house is rather modest 70's semi and appears to have been built to a tight budget. I don't have any fall pipes from the gutters at either front or back of the property. Instead, the roof water runs away down the fall pipes on my neighbour's gable end. Hence no SW drains to link into. The only drainage i appear to have is a soil stack with is joined by foul water pipes from bathroom and kitchen.

Can anyone advise me whether i'm allowed to connect the linear drain to this foul water drain or is it a case of investing in mop and sandbags?

Cheers, G

Posted: **Tue Apr 03, 2012 10:32 pm**

Maybe a case for a soakaway under the driveway as i assume your house is terraced? And thierfore a slim frontage.

Posted: **Tue Apr 03, 2012 10:56 pm**

Thank you for the suggestion. The house is a semi but still not endowed with much width from the edge of the road. Its about 6 metres from roadside to house/garage but a reasonable width available.

I have a couple of concerns re the soakaway option.

First, would a soakaway cope with typical rainfall over an area of block paving approx 25sq metres especially through winter months. I guess there will be calculations somewhere for me to work this one out.

However, my second concern, the garden rises up a significant slope to the road and a soakaway would be upstream of the garage. I'm worried this could compromise the foundations of the garage?

Have you suggested the soakaway because the connection to the foul water drain is a no-no?

Posted: **Wed Apr 04, 2012 10:33 am**

Having had more time, i think i've found the answer to my own question. Its a no can do to run off storm water into the foul water drain in all but the most exceptional circumstances.

So i need to consider a soakaway. The most obvious place to site a soakaway seems to be the back garden which slopes away from the house and garage. This will involve digging a trench of approx 7 metres from front to back of the house but then there's the decking to negotiate. This is laid across the full width of the garden so i cant go around it and i'd rather not spoil it by dismantling it. I'm wondering whether i could run a drain across the surface of the ground under the decking? At the other side i could then sink the drain back underground and on towards the soakaway? Is such a plan an acceptable method and if so, is there a special type of pipe to use over the surface?

Posted: **Wed Apr 04, 2012 4:40 pm**

you need to use grey pipe above ground which is 3 times more expensive than orange
all top do with UV ratings
LLL

Posted: **Wed Apr 04, 2012 5:35 pm**

Appreciate the info LLL. At least it will only be a shortish run of grey needed. Thank you.

The Brew Cabin

Wot no drains? - Missing sw system