Sewage pipe cap

[coltmanneil]

Hi ,
I need to put a cap/stopper on the rodding pipe ( top) after finding rats were running along here . I bought a 4 inch 110mm and screwed it right up but it’s still slightly too small . Any ideas what would be the size we would need to cap this . We have put into the inner pipe for now but it’s not solid .
These homes were built 50s. Plus is it the inner pipe we should be capping or the outer , thanks .

 

[Madrab]

You may need to fit a vermin barrier valve - just google it, there are a number of different types

 

[CBW]

Looks a bit like an interceptor, but surely if you blank the top, they (the rats) will still be in there?