Leaking soil pipe
 

Recently I have converted a bedroom into a bathroom, and the other
weekend was connecting the waste from the toilet to the soil stack.
This had been agreed with Building Control so happy happy.
However, I have had an issue with pipe sizes. Foolishly I thought that
my Hepworth 4"/110mm pipe would connect quite hapily to the stack.
There is a small size difference, but with a bit of wadding I can get
a reasonable seal, but it needs something better as the joint seems to
be weeping.
I was thinking of using something like plumbers mait on the joint, but
I need quite alot, is there a bitumous tape or something which I cna
use, or would a cement based compound be available.
I have also found a hole elsewhere which needs plugging as well.
Cheers
Bean