bath trap anti-vac?

[Mgrant]

If a bath waste is bossed in to a soil stack separately does this mean it doesn't need an anti-vac trap? Or is it till be off fitting one.

 

[woodsy]

I would always put an anti vac trap on.

 

[chris watkins]

IMHO no correctly installed waste pipe should ever need an anti-vac trap fitted on the end.

They are a mechanical device which is prone to go wrong.

We never needed them when before.

Part H = 40mm dia waste laid at 18 - 90mm per metre fall, on a maximum run of 3M, with a standard low line bath trap with a min of 50mm depth of seal.

Job done :cheesy:

 

[Alert]

No it shouldn't as Chris says if it runs correctly and doesn't exceed in length

 

[1Steven]

Why do I still come across shallow seal traps on new build type properties?

 

[Alert]

Probably building inspectors overlooking them

 

[townfanjon]

Why do I still come across shallow seal traps on new build type properties?

Cheap !! Lol

 

[Mgrant]

I BROUGH anti vac. Next time in this situation I wont. Will this one be ok thou?

 

[chris watkins]

Yes, what one did you get?

 

[JCSPLUMBING]

If basin is teed into bath waste then it ideally should be upgraded to 2 inch before the stack. When is this ever done though?

 

[Mgrant]

So same goes for a basin if the basin has its own waste pipe to a boss in to a 4inch stack. Is an anti vac pedistal trap not needed? What do most new build firms do? Fit anti vac everywhere as a precautionary measure?

 

[JCSPLUMBING]

Wouldn't be needed as no chance of self syphoning as no other traps are in line.

 

[Mgrant]

Thanks, what about a sub stack without a vent that has a toilet then a basin connected via a drain connector and boss. Would a anti vac on the basin help?

 

[Mgrant]

For a downstairs cloakroom

 

[Mgrant]

Would an av trap on the basin act a tiny bit as a vent. Even though most stub stacks aren't vented

 

[JCSPLUMBING]

Stub stacks with a basin waste attached to the pipework should ideally have an air admittance valve fitted. I'm sure an anti vac trap would be fine though. I've done this in the past and all's been ok.

 

[Howsie]

Nobody spends money unnecessarily and if you do it right you don't need one.

 

[Howsie]

AAV on sub stack. Agree 100%.