Hep2O in blockwork

[MortarThePoint]

I know you can chase Hep2O pipes into a wall and plaster over, but fittings not a good idea. What's the normal way to handle the need for a fitting then? For example a pipe leading to a basin or the like will need an elbow at the end. A basin may allow an open hole in the wall to be hidden. But a toilet cistern or radiator wouldn't.

 

I have to feed a basin and high level cistern both mounted on blockwork. 10mm pipe coming down from ceiling so want to use a tee to feed the high level cistern and would also need elbow to make the corner to bring pipe out of wall at each.

[Conor]

Brass compression fittings.

[MortarThePoint]

8 minutes ago, Conor said:

Brass compression fittings.

 

Onto the Hep2O pipe?

[PeterW]

16 minutes ago, MortarThePoint said:

but fittings not a good idea. What's the normal way to handle the need for a fitting then?

Why not..? Tend to wrap a bit of masking tape over the release plate and the joint but if it’s solid then I don’t worry and they get clipped in and plastered over.

[MortarThePoint]

1 minute ago, PeterW said:

Why not..? Tend to wrap a bit of masking tape over the release plate and the joint but if it’s solid then I don’t worry and they get clipped in and plastered over.

 

Don't fittings require a bit of movement?

[markc]

Hep20 fittings (no compressions) bury them in walls or floors and forget about them.

we have tried Hep20 for low pressure hydraulics and it’s amazing just how much pressure and abuse it will stand.

Edited September 27, 2022 by markc

[PeterW]

10 minutes ago, MortarThePoint said:

 

Don't fittings require a bit of movement?

For ..??? I tend to make sure they don’t move as then the pipework is fixed  securely and doesn’t crack the plaster. A 22mm nail in pipe clip fits over a 15mm fitting nicely behind the collet.

[Gone West]

7 minutes ago, PeterW said:

For ..???

I thought plastic plumbing pipes expanded more than copper so you had to be careful plastering them into a wall.

 

"The coefficient of thermal expansion
of polybutylene is 1.3 x 10-4/m/ºC.
This means that the pipe expands by
1.3mm per metre of pipe for every
10ºC temperature rise."

 

http://www.tglynes.co.uk/downloads/tgl-coshh-tech-hep20-performance.pdf

 

[MortarThePoint]

13 minutes ago, PeterW said:

For ..??? I tend to make sure they don’t move as then the pipework is fixed  securely and doesn’t crack the plaster. A 22mm nail in pipe clip fits over a 15mm fitting nicely behind the collet.

 

The grab part of the fitting needs movement, but I guess it's pressure tested before plastering so perhaps just the thermal expansion could serve to loosen the hold of the grab ring.

[PeterW]

3 minutes ago, Gone West said:

I thought plastic plumbing pipes expanded more than copper so you had to be careful plastering them into a wall.

 

"The coefficient of thermal expansion
of polybutylene is 1.3 x 10-4/m/ºC.
This means that the pipe expands by
1.3mm per metre of pipe for every
10ºC temperature rise."

 

http://www.tglynes.co.uk/downloads/tgl-coshh-tech-hep20-performance.pdf

 

Next line down

 

“Where the pipe is totally restrained in a concrete floor (e.g. as underfloor heating), the stresses are so low that they are absorbed by the material”

 

Never had an issue and tbh it’s usual that the pipework exits from the top of the wall into a void anyway. 

[PeterW]

1 minute ago, MortarThePoint said:

 

The grab part of the fitting needs movement, but I guess it's pressure tested before plastering so perhaps just the thermal expansion could serve to loosen the hold of the grab ring.

Why does it ..?? Once fitted, unless you are actively removing the fitting nothing is moving and nothing will “loosen” the fitting. Speedfit are a whole different ball game as they have an external collet release. 

[MortarThePoint]

Here are some dimensions

[MortarThePoint]

Just now, PeterW said:

Why does it ..?? Once fitted, unless you are actively removing the fitting nothing is moving and nothing will “loosen” the fitting. Speedfit are a whole different ball game as they have an external collet release. 

 

I guess if the pipe is gripped by the plaster then it won't be a problem but if you had unconstrained pipe expanding into a constrained fitting you might have an issue.

[PeterW]

24 minutes ago, MortarThePoint said:

 

I guess if the pipe is gripped by the plaster then it won't be a problem but if you had unconstrained pipe expanding into a constrained fitting you might have an issue.

How..???? I’ve buried hundreds of these as has @Nickfromwales and I don’t think I’ve ever seen an issue… Use the correct insert, don’t try and use chrome pipe as tails, and then just clip back and plaster over.  If you’re worried about pipe movement you can wrap the pipe with fibre insulation as plaster bonds onto it. 

 

 

[Nickfromwales]

2 hours ago, Conor said:

Brass compression fittings.

Hell no !

 

Naughty step for you. I’ll let you know when the 30 mins is up. 

[Russell griffiths]

Is it not easier to batten out the wall rather than chasing in pipes. 

[Nickfromwales]

52 minutes ago, PeterW said:

How..???? I’ve buried hundreds of these as has @Nickfromwales and I don’t think I’ve ever seen an issue… Use the correct insert, don’t try and use chrome pipe as tails, and then just clip back and plaster over.  If you’re worried about pipe movement you can wrap the pipe with fibre insulation as plaster bonds onto it. 

 

 

Yup. Fit and forget with Hep2o. 

 

 

2 hours ago, MortarThePoint said:

I have to feed a basin and high level cistern both mounted on blockwork. 10mm pipe coming down from ceiling so want to use a tee to feed the high level cistern and would also need elbow to make the corner to bring pipe out of wall at each.

Use a bullnose T ( 10x10x15 centre ) so you have 15mm coming off the tee, then you can go to chrome and compression onto a stub of copper. 
For the basin I’d just leave a neat recess out of site with the 10mm pipes ending in 2x 10mm M&F bends with 2x 10x 1/2” Hep2o vs brass adaptors, and the flex is from the taps straight onto those. 
 

[MortarThePoint]

25 minutes ago, Nickfromwales said:

Use a bullnose T ( 10x10x15 centre ) so you have 15mm coming off the tee, then you can go to chrome and compression onto a stub of copper. 
For the basin I’d just leave a neat recess out of site with the 10mm pipes ending in 2x 10mm M&F bends with 2x 10x 1/2” Hep2o vs brass adaptors, and the flex is from the taps straight onto those. 

 

Do you not rate the Hep2O tap tails?

https://www.screwfix.com/p/hep2o-push-fit-flexible-tap-connectors-15mm-x-x-300mm-2-pack/1250f

[PeterW]

44 minutes ago, MortarThePoint said:

 

Do you not rate the Hep2O tap tails?

https://www.screwfix.com/p/hep2o-push-fit-flexible-tap-connectors-15mm-x-x-300mm-2-pack/1250f

They are ok but don’t forget to put the

isolator in 

[MortarThePoint]

13 minutes ago, PeterW said:

They are ok but don’t forget to put the

isolator in 

 

Each room is going to be isolatable back at a manifold in the plant room, so I am not planning to have isolators at basins etc. Does that sound sensible?

[Nickfromwales]

9 hours ago, MortarThePoint said:

 

Each room is going to be isolatable back at a manifold in the plant room, so I am not planning to have isolators at basins etc. Does that sound sensible?

Yup. That’s the norm on every one of my installs 👌👍

[Nickfromwales]

10 hours ago, MortarThePoint said:

 

Do you not rate the Hep2O tap tails?

https://www.screwfix.com/p/hep2o-push-fit-flexible-tap-connectors-15mm-x-x-300mm-2-pack/1250f

Why buy those when most basin taps come with flexis which screw straight onto a 1/2” thread? 
Is it a mono block tap or traditional 2 tap hole basin with ‘normal’ taps? 

Edited September 27, 2022 by Nickfromwales

[Nickfromwales]

I’d prefer bent tap connectors straight onto the 2 taps, if not a monoblock. Then the pipes / flexis won’t be on show.