Sealing pipes thpugh rendered walls

[Dyson]

Q. I have a number of waste pipes ( soil stack and general waste pipes) exiting through newly rendered external walls. The pipes have about 20mm gap round them . Should this void be filled or left. I think rain water may seep in?

 

[Arti]

Foam the gap then get the plastic covers if that makes sense

 

[Dyson]

Thanks for your help. But is it a necessity or a preference. My builders have left. Not sure if they’ve forgotten to go it?

 

[Arti]

Thanks for your help. But is it a necessity or a preference. My builders have left. Not sure if they’ve forgotten to go it?

If it was my job it would be a necessity purely on the basis it looks unfinished. Maybe they did forget. But if your not happy get them back

 

[Dyson]

As I look again it probably is only 10 mm. Looks unfinished to me, BUT the main reason for asking is whether rain ingress would cause damage to render or inside house damp?
What fo you think re potential damage. Thanks for help so far. This is one of about 7 pipe holes

 

[Arti]

View attachment 33366
As I look again it probably is only 10 mm. Looks unfinished to me, BUT the main reason for asking is whether rain ingress would cause damage to render or inside house damp?
What fo you think re potential damage. Thanks for help so far. This is one of about 7 pipe holes

its going to allow water through it obviously, for the cost and time to foam them and cover them up its a no brainer. You can actually foam them then cut it back 15mm and render it. If its recently been done the patch will dry the same colour and you should barely notice it

 

[Rigsby]

Mask up well if you foam it. If it expands and gets onto your rendering it will stain. As said above patch it up but if you are really keen create a 1mm gap around the pipe and render and seal with silicone. Hot water makes the pipes expand.

 

[Andy M]

Could you not just put a small shroud over it?