What do people consider of these traps?

 

I'd not come across them before until some work in our house, the previous owner had installed one but it seemed to of been jammed up and open.

 

Are there better ones?

I fitted one in a rental I have 

We where getting a bit of colour from the ensuite 

The guy at the plumbers merchants asked if I was having problems with rats 

Sitting on the loo has never been the same since 

 

Surely these exist as a bodge to "fix" a dodgy drainage system?  Properly designed they should not be needed.

 

Would a waterless trap do the same thing?

I have one on my downstairs shower, because when I added a bath and new shower to the bathroom upstairs last year I started getting some washback into the downstairs shower.

 

F

I'm planning on making use of a 2nd soil on the house which til now had two pairs of toilet, basin, shower.

 

And a dish washer! Bit random how many other people have a dish washer under their stairs away from their kitchen? But anon.. .

 

I'm planning on adding a sink for utility a washing machine dish washer and a toilet sinkin new location the toilet is the furthest item away from the stack....

 

So my question was are These valves of value in protecting the dishwasher etc....

A couple of years on we haven’t had any complaints