Sewage smell in kitchen - Drainage

[gentext]

Hi,

Long story short! House renovation/extension 3 years ago to add a new kitchen space. A drain was laid into the floor to accomodate a central island. This drain goes direct to the septic tank and links into a foul drain from an upstairs bathroom.

The kitchen was fitted 6 months ago, but the seal on the link between the drain in the floor and the waste pipe from the sink leaks sewage smells when the wind blows from one direction — the rest of the time it's OK, no smell. Prior to the kitchen installation, the drain pipe was covered by a plastic bag that we taped to prevent smells coming back.

I've been told that a U-bend should have been inserted between the drain in the kitchen and the point where it meets the foul pipe from the upstairs bathroom. To install this U-bend now is out of the question because the new kitchen floor is laid and there is underfloor heating. Is ther anyway we could insert a U-bend in the garden to prevent the wind blowing the seage smell back up the pipe?

Many thanks,

CB

[Mark B]

Putting a u bend/P-trap in the pipe run outside the property probably would cut down and possibly stop smells from being blown up through the pipe indoors, solving the problem.

mark

[Tony McC]

In theory, there's nothing to stop you inserting a trap on the pipeline in the garden, but the precise layout of your system will determine how effective such an installation would be. A sharp trap downstream of the SVP could be a potential blockage point.