DIY Doctor UK DIY Forums

Hi, I am building an extension to my house and being "Ex" building trade (Chippie) I thought I would do the start of the work to DPC myself. The problem I have is that where i have come through the cavity wall with a soil pipe for the ground floor Wc, I don't know what to do around the pipe. I have placed Lintels over the pipe which now runs through a square ish whole with about 50mm clear all round. What do I now do to stop the following.
A) backfill going in the whole around the pipe from outside
B) lean mix in the cavity coming out of the hole.
C) MOT/hardcore falling in from inside
c) insulation from above falling in (will be "blown" with insulation when wall complete)
Everybody seems to have different ideas but no difinitive answer.
Any help appreciated

[quote="Andy Fielding"]Hi, I am building an extension to my house and being "Ex" building trade (Chippie) I thought I would do the start of the work to DPC myself. The problem I have is that where i have come through the cavity wall with a soil pipe for the ground floor Wc, I don't know what to do around the pipe. I have placed Lintels over the pipe which now runs through a square ish whole with about 50mm clear all round. What do I now do to stop the following.
A) backfill going in the whole around the pipe from outside
B) lean mix in the cavity coming out of the hole.
C) MOT/hardcore falling in from inside
c) insulation from above falling in (will be "blown" with insulation when wall complete)
Everybody seems to have different ideas but no difinitive answer.
Any help appreciated[/quote]pack it with stiffish mortar and then smooth it with a pointing trowel round the pipe,don't forget to keep your cavity fill at least 150mm below dpc. Cheers