Condensate pipe

[mo7]

I have a 32mm condensate pipe sticking out the wall for a combi.

It comes out the wall about 1m from the ground. It then needs to turn left and travel 3m where it will join right at the bottom of a soil pipe through a strap on boss.

My question is - can I put the 3m bit (as long as it is running down) underneath the patio?

Is it more likely to freeze just below the indian sandstone patio when surrounded by mortar than it is on top of the pato?

Would putting the 32mm inside a 40mm as extra sleeving help or make it worse?

I could also put some of that foam stuff around it but it may make it a bit chunky.

 

[LPC]

If you don't want the 3m horizontal and you're willing to lift the slabs anyway, just dig a soakway under the slabs directly below the wall exit.

 

[mo7]

My original post probably wasn't that clear.

The pipe comes out the wall about 1m off the ground - either way it will have to come straight down to the floor

I can then

1 - do a soakaway
2 - take it to the sil stack

I am guessing a soakaway will need to be deep and actually allow the water to soak away - problem is it is all concrete there for the foundations.

My patio is already up and I am having a new soil stack going in so all I need to go is put a small channel is for the 32mm pipe to run into the soil stack. I just wasn't sure whether it made a huge difference putting it under the patio.

One problem is that if the pipe does freeze it makes it harder to defrost it. I wonder if I can put somesort of access point like you get with soil stacks (rodding eye) so that I can always detach the part on the wall and bung some water down it.

 

[GrahamM]

As above. If you going to lift slabs anyway keep pipework as short as possible into soakaway.
500mm from building obviously.

 

[GrahamM]

I would look at one they condensulate xtream kits if soakaway is not option.
If done properly freezing should not be an issue.
Condi pump internal defo not an option?

 

[LPC]

It'll probably be ok if you've got a decent slope. Maybe go from 32mm to 40mm with an air gap, then if it does freeze you can just pop some water down the air gap. I'd say it's very unlikely a 40mm would freeze just with a condense discharge though.

Soakaways don't have to be that deep, and they have to be 500mm from the building so i'd check if you have concrete there (i'd be surprised if you did). Really you only need dig as deep as you need to get the soakaway in there, generally around 400mm-500mm deep.