compression joint below floorboard

[dizz]

Can we use a compression joint below the floorboards on cold water pipes or should it be an end feed fitting soldered?

 

[lifesagasman]

for water, yes. for gas, no.

wait for the torrent of contradictions...

 

[dizz]

Thanks - I couldn't really see it in the regs anywhere.

 

[lifesagasman]

best practice, of course, would be a soldered joint. but that's just my opinion.

 

[Andygasman2010]

Soldered all the way for me.... A compression joing is bound to leak at some point during it's life. Tempting though, especially with wet pipes.

 

[Corgigrouch]

Sods law states that the more inaccessible the fitting, the more likely it is to leak a month down the line....

 

[neds]

Best practice is no compression fitting under floors etc... Only one inaccessible compression joint can be used and that is manipulative joints underground and that is for Table Y copper.

What you have to ask yourself is is it worth the hassle, compression joints under floors will have forces acted on them more than above ground because of invariable foot traffic. This can cause the joint to fail.

 

[tamz]

Can we use a compression joint below the floorboards on cold water pipes or should it be an end feed fitting soldered?

Yes although soldered is preferred.

A compression joing is bound to leak at some point during it's life.

How do you figure that one out. Don't believe all you read in books!

Only one inaccessible compression joint can be used and that is manipulative joints underground and that is for Table Y copper.

These can actually come apart more easily than a nut and ring ( if you don't believe me just give one a yank) and nowadays are only rarely seen other than underground.

compression joints under floors will have forces acted on them more than above ground because of invariable foot traffic. This can cause the joint to fail.

The joint is under the floor and also presumably under the joist. Unless a family of elephants move in or the house is let out for weekend raves this will not be a problem.

OP if you are finding this decision a problem stick a speedfit on it.

 

[lifesagasman]

for water, yes. for gas, no.

wait for the torrent of contradictions...

i told you....

 

[adlplumbing]

sonder is always best but if it wet and ball ache to solder could always use a plastic one
(yes i am know going to get abuse)

 

[PEDANTICVINDICTIVEMAN]

how about a jubilee clip and bit of hose pipe

 

[lifesagasman]

the efficacy of your remedial works would be questionable. surely 2 clips would be required.

disgruntled of t'north

 

[Axel]

No! No! No! Don't do it!

I don't care what the regs do or don't say - or the opinion of any old or new plumbers - Don't use compression under floor!

Why? because some poor sod like me comes along one day to replace a rad valve etc and a slight twist on the pipe above floor level loosens the compression joint below floor level. Oh dear, the client has a new hardwood floor / porcelain tiles laid over plywood laid over the floorboards. Sorry m'am, it's all going to have to come up...or we might have to pull down some of the downstairs ceiling.

 

[PEDANTICVINDICTIVEMAN]

the efficacy of your remedial works would be questionable. surely 2 clips would be required.

disgruntled of t'north

Two clips it is then

 

[lifesagasman]

you've just doubled your thanks bank...