Windsor trap/drain

TeamPlum

My Windsor trap/interceptor trap is smashed at the front, resulting in blockages as the foul waste gets snagged on the broken bits.

I need it replacing, but have no idea who would carry out such a job. Many of the unblocking services claim they can do, I'm sure there would be an added premium for this.

Can anyone advise on this? Anyone had it done? In the Nottinghamshire area.

Cheers, Tom

The_Manager

I guess you've had this sorted by now and my reply is too late, but some info that could be useful...

Firstly, it's a Winser Trap, not a Windsor Trap.  Minor usefulness, but maybe just interesting waffle.

Secondly, these are old drainage fittings that were introduced in the late 1900s and used up until about the 1950s ish to stop the passage of foul air from the sewer up to the house, but drainage design has improved since then, and nowadays, most of our homes have a drainage pipe that pops up above the roof gutter line to vent the sewer at a high level away from windows (known as a SVP - Soil & Vent Pipe), so the need for a Winser Trap is null and void anymore.

These cause all kinds of problems with blockages etc, but there is no requirement to have one fitted to your drainage system at all, except in only 2 London boroughs under local government rules, but even there it is not policed and these are just old rules that should be repealed.

However, the Winser Trap as a drainage fitting is still available from builder's merchants today, and they can be replaced if desired, but put simply, the best answer is usually to break out the old Winser Trap (it's basically just a U bend in your drain run going out the main sewer) and replace it with a 'straight-through' piece of pipe.  Where the U bend is at the bottom of a manhole, this is known as a Winser Trap and this work can usually be done from inside the chamber (so no external digging required).  Where the trap is not in a chamber but just has a small vertical rodding point directly above it, the trap is known as a Buchan Trap and in order to knock one of these out, there are few options other than to dig it out, so this is more time consuming, costly and disruptive.

I hope this helps.

grumbler

The_Manager said:

Secondly, these are old drainage fittings that were introduced in the late 1900s and used up until about the 1950s ish to stop the passage of foul air from the sewer up to the house, but drainage design has improved since then, and nowadays, most of our homes have a drainage pipe that pops up above the roof gutter line to vent the sewer at a high level away from windows (known as a SVP - Soil & Vent Pipe), so the need for a Winser Trap is null and void anymore.

Any independent confirmation of this?

I think the pipes serve absolutely different purpose - to let the air in to avoid syphoning (and can be replaced with an air admittance valve inside the house).

The traps may well be not needed, but not because of the pipes.

The_Manager

Manholes or inspection chambers fitted with a Winser Trap 'should' always have a vent pipe connected directly to the side of the manhole and popping up above ground somewhere near by.

So, even in them olden days, the system still had to be vented.  Nowadays it is simply vented by the soil and vent pipe above roof level.

Replacing a fresh air vent with an air admittance valve is possible, but should be avoided if possible.  AAVs are mechanical devices that can fail leading to nasty consequences, and the chances of a fresh air pipe to the outside world failing are almost nil.

Simple is best.

This is what an intercepting chamber 'should' look like, but there are local and regional variations all over the country: