Blanking Off Plug for 56mm Strap on Boss?

[jonjack]

Hi


I have discovered a leak from my waste stack in the roof space of my extension.
It seems that at some point in the past before I owned the house someone fitted a plastic strap on Boss to the existing cast iron stack but it was never used, nor a blanking off cap fitted it seems.

I can't seem to find a rubber blanking off cap to plug the hole - can anyone kindly point me in the right direction?
I can't find anything at Wickes, B&Q, or Build Center.

The hole diameter is about 56mm.

cheers

 

[TomLane]

Are there any appliances above the strap boss?

Seems odd that it should leak if its in the roof space?!

As far as I'm aware you won't find a cap/plug so you'll have to get an adaptor (40mm/32mm) then put a small piece of pipe to suit & then an access plug with cap.

There may be a simpler way but at this time on a Sunday this is the only solution I can think of.

 

[snowhead]

50mm Solvent Weld Access Plug | 50mm Solvent-weld Waste | Drainage Online

Wolsey Pipe Center or decent Independant Merchant, it's out of B & Q's league.

alternate, rubber 50mm to 40mm reducer and 40mm blank

 

[jonjack]

Are there any appliances above the strap boss?

Seems odd that it should leak if its in the roof space?!

As far as I'm aware you won't find a cap/plug so you'll have to get an adaptor (40mm/32mm) then put a small piece of pipe to suit & then an access plug with cap.

There may be a simpler way but at this time on a Sunday this is the only solution I can think of.

Hi Tom,

The extension is ground floor only, but house is 2-story. Fortunately, only the upstairs sink connection is above the boss so only sink waste is leaking. The WC waste from upstairs connects to the stack just below the boss fortunately.
Thanks for the suggestion but the diameter of the boss hole is 56mm.
I get the idea though.

cheers
Jon

 

[jonjack]

50mm Solvent Weld Access Plug | 50mm Solvent-weld Waste | Drainage Online

Wolsey Pipe Center or decent Independant Merchant, it's out of B & Q's league.

alternate, rubber 50mm to 40mm reducer and 40mm blank

Cheers Snowhead,

Looks like I might try solvent welding then.
I'm hoping that the external diameter of the plug is 56mm since this seems roughly the diameter of the hole in the boss, even though its hard to get at and difficult to measure accurately.

Thanks
Jon