drainage

Below ground drainage and ducts installed.

This morning saw the last delivery of type 1stone arrive on site for compaction, which was laid pretty quickly. The first photo shows the positions of the service pop-ups marked out.

After that the below ground soil drainage pipes were laid, as well as a few 50mm diameter ducts to take the other services, namely electricity, mains water and BT.

We also did a first airtightness test on the below ground drainage to ensure that it passes before the test is witnessed by the building standards surveyor tomorrow morning! The third photo shows one of the bungs in the vertical section of pipe - the other goes at the other end of the pipe inside the inspection chamber. The pipe is then air pressure tested using a manometer; it is required to hold at the prescribed level for 5 minutes to ensure there will be no leakage from the pipes once they are in use. It is important to do this test multiple times, both before and after the pipes have been back-filled to make sure they have not been disturbed during the back-filling and re-compacting process. After tomorrow we will be at the point of the final gravel layer and officially 'out of the ground'. Phew!