Getting enough run on bath?

[Ben ten ten]

Hi. I am going to be extending my bathroom to include a bath. The problem is it is solid floors, and I have to run a pipe from a vertical soil pipe with my outlet at floor level with a 3.5 meter run(and three swept bends) to the bath. I know I need a minimum of 18mm gradient a meter for the waste. My questions are, is there a bath trap with a higher outlet than the others(I have only used the bath traps with very shallow seal death before)? If I set the bath at the standard 505mm to the lip would the trap outlet height give me enough gradient for the water to run away properly? If I do have to raise the bath significantly, how to I make good the bath panel(it been too short in height)? Any help and suggestions would be great? Thank you

 

[muggles]

In order to comply with Building Regs, you'll need to use a trap with a minimum 50mm water seal. A McAlpine SM10E might give you a bit of extra height. You should really be aiming for 44mm per metre fall, especially over such a long run, and because it's more than 3m Building Regs require you to upgrade the entire run to 50mm (2") diameter pipework

You can always do away with the standard bath panel and get an adjustable one or make your own

 

[Ben ten ten]

Thank you. Why do they sell shallow seal traps for baths if you need a minimum of 50mm water seal? Doesn't seem to make sense.

 

[TCCHeating]

Thank you. Why do they sell shallow seal traps for baths if you need a minimum of 50mm water seal? Doesn't seem to make sense.

Same reason you can go to a shop and buy a bong

But seriously. Google hepvo valve.

Commonly called a 'fanny trap' by the trade. (You'll realise why when you see one!)

Fanny traps can get you out of the s hit when you've got limited space for a normal trap

 

[muggles]

Thank you. Why do they sell shallow seal traps for baths if you need a minimum of 50mm water seal? Doesn't seem to make sense.

Same reason you can go to a shop and buy a bong

But seriously. Google hepvo valve.

Commonly called a 'fanny trap' by the trade. (You'll realise why when you see one!)

Fanny traps can get you out of the s hit when you've got limited space for a normal trap

Outlet is lower than a standard trap though, so it doesn't help in this situation

 

[muggles]

Thank you. Why do they sell shallow seal traps for baths if you need a minimum of 50mm water seal? Doesn't seem to make sense.

Many things are available for sale that don't comply with regs...simple answer is that it's cheaper and everyone wants to save a few pence where they can

 

[Ben ten ten]

Thanks. Would a trap with less seal have a far higher chance of self siphonage?

 

[Jackrae]

Thanks. Would a trap with less seal have a far higher chance of self siphonage?

Yes, and once it's sucked the seal out of the trap you'll get foul gas coming back up the line.

 

[Ben ten ten]

I understand I am going to have to use 2inch waste pipe, but obviously the trap of the bath is 1 and a half inch, so do I just have a reducer and a 2inch straight right after the trap, or do you get special 2inch traps for baths?

 

[oph]

Not all systems discharge directly into the soil stack. If it went via a hopper head then you can use a shallow bath trap. No chance of self siphonage

 

[BigSnoopy01]

shall traps are good for replacing like for like as most old metal traps were that size. Alot of new builds jobs still use shall bath traps because of the depth of the bath and not being able to sink the trap into the timber floor. Its not right but its done.

 

[muggles]

I understand I am going to have to use 2inch waste pipe, but obviously the trap of the bath is 1 and a half inch, so do I just have a reducer and a 2inch straight right after the trap, or do you get special 2inch traps for baths?

1.5" trap, upgrade pipework to 2" as soon as you're out of the trap

 

[Ben ten ten]

Thanks