Channel drainage above garage damp course

[Robo]

Hello.

I'm running drainage across my house and garage but the garage is lower than the house. The drains will be 2 bricks below the house dpc but 1 above the garage dpc.

If I were to paint the bricks 150mm above the drains with wickes damp proof course paint would this be ok?

Many thanks.

[local patios and driveway]

Nahh that will just trap moisture behind and above the damp course, put a picture up for the lads to have a look.

[Robo]

This is where the drains are going to to connect. I ideally want them to all be level but this means breaching the dpc

[Robo]

This is the house on right garage on left.

[Pablo]

http://www.pavingexpert.com/dpc01.hhtm
middle of the page dry area arrangements.



Edited By Pablo on 1330769364

[Robo]

I did have a read of that before but am looking for a solution to keep the drains the same level. A builder has suggested installing some lead flashing 150mm up 50mm down. Would this be acceptable?

[local patios and driveway]

Do not listen to that builder! What a bodger. The only solution i would be happy with is the whole surface 2 courses below garage dpc. Anthing you put infront of the bricks that are above the dpc will be a trap for damp. They need to be exposed so they can breath and stay dry.

[DNgroundworks]

Can you not have the drains finishing 4 bricks below damp on the house, and 2 below the garage dpc to get them on the same level and have a step to get in the house door? whoever built the garage made a cock up there, surely they should have got FFL and the damp courses of the two buildings level?

LLL knows a bit about lead flashings and work arounds hell be along shortly

[lutonlagerlout]

code 4 lead flashing is an expensive but acceptable workaround
the linear drain must be flush with the garage floor that is your datum, the drain should then cut across the front of the house at that level with 1:80 fall approx
you will probably need to build a step or ramp to gain access to your door
a picture of the whole frontage would be handy
cheers LLL

[Robo]

Lowering the whole garden would be a nightmare as the whole garden would need to be hand dug but I agree a 2 and 4 below would be best.

I've thought about staggering the drains but a 200mm wide void is going to be a hazard with small children around.

What I'm looking at now is a 150mm hardcore base upto 1 below damp, drain on top of this 1 above damp with flashing 1 below and 2 above damp.

The garage is single skin so if I have problem I'm sure they wil soon show themselves.

Things are never simple!

[lutonlagerlout]

I have staggered drains height wise before but we had to build a small retaining wall to overcome the difference in levels
a picture of the whole frontage would be handy
cheers LLL

[Forestboy1978]

Why would the garden have to hand dug? You can if necessary get a mini digger through a front door and through the house if you have no gate! Worse case scenario!

[seanandruby]

Bit of a tight space between there to use a digger, you wouldn't be able to swing the arm, so you'd have to keep pulling it back.

[Robo]

A diggers out the question im afraid, as is lowering to 4 below damp as this would mean replacing the mains sewer pipe where the man hole is on the patio.