Pipes in Kingspan

[verdigrey]

Hi Guys , Could do with advice please . We rarely do new build , but we have been asked to Quote for all Plumbing in a detached 3 bed house . U/F in screed ground floor and Rads on !st floor .
In Kitchen they want an Island Unit with Sink , so I need to get 2x15mm pipes to sink and 1 x 40mm waste pipe away . The floor is block and beam with 100mm kingspan and about 70mm sand and cement screed . Is it best to install pipes onto conc floor BEFORE the kinspan go,s down and let them fit around it . Or cut grooves into Kingspan after for pipes ??
Also same question for Cold and Hot services ? We will afterwards fit U/F pipes by staple into Kingspan . We have just got quotes for 2 different U/F systems . J/G plastic and Hetta type aluminium pipes . Hetta is about two thirds the price , is it true that the Aluminium pipes are easier to lay ??
Thanks

 

[jonnyswamp]

Fit your pipes first, lag them and fix them down with strap banding then let someone else cut the insulation
Same with your waste pipe (without the lagging) making sure of a fall

 

[verdigrey]

Thank you Jonnyswamp , brill

 

[ShaunCorbs]

only other comment make sure your waste pipe eg the fall is fixed good i mean really good so it cant be move (ie the fall taken out ) as your not fitting the kingspan

dont want to come after all the floor has been done and someones been a bit heavy handed when laying the floor and now you have no fall on your waste pipe eg water doesnt run away

 

[chris watkins]

Water Regs require that pipes are accessible for repair / replacement, don't think that having them 170mm under a screed & insulation would meet the requirements !

Recommend pipe-in-pipe cut into the insulation with foil tape to keep it in place, then U/F above in screen will not warm the cold mains water.

Pipe in pipe is continuous length of plastic pressure pipe inside a corrugated conduit, this meets requirements as pipework can be withdrawn & new pushed through if it gets damaged.

 

[jonnyswamp]

How many showers have pipes chased into the wall
I wouldn't lose any sleep over it

 

[tolly]

Id also say do the hoizontal part of the waste run in 2" and try to be on site when the celotex is laid and cut around it to make sure the site labrador doesnt kick the carp out of it.

Chris is also right in that you shouldnt really have soldered fittings on hot and cold services underneath the screed, how many people listen to this is another matter though.

 

[ShaunCorbs]

Water Regs require that pipes are accessible for repair / replacement, don't think that having them 170mm under a screed & insulation would meet the requirements !

Recommend pipe-in-pipe cut into the insulation with foil tape to keep it in place, then U/F above in screen will not warm the cold mains water.

Pipe in pipe is continuous length of plastic pressure pipe inside a corrugated conduit, this meets requirements as pipework can be withdrawn & new pushed through if it gets damaged.

so how would you do this with water mains

 

[chris watkins]

How many showers have pipes chased into the wall
I wouldn't lose any sleep over it

Showers tend to be on first floor & short distance of buried pipe, any leak soon noticeable, not quite the same in a ground floor kitchen under that lot is it you may never know it was leaking.

Do you have the same cavalier attitude to the gas regulations Jonny ?

 

[chris watkins]

so how would you do this with water mains

Sorry don't understand do what with a water main ?

The cold water to the kitchen island would be the mains wouldn't it ?

 

[plumben]

I'd run the waste pipe In 2" if its going to buried straight run to a rodding eye outside

 

[ShaunCorbs]

Sorry don't understand do what with a water main ?

The cold water to the kitchen island would be the mains wouldn't it ?

you said all pipes must be accessible, water mains arnt

 

[jonnyswamp]

Showers tend to be on first floor & short distance of buried pipe, any leak soon noticeable, not quite the same in a ground floor kitchen under that lot is it you may never know it was leaking.

Do you have the same cavalier attitude to the gas regulations Jonny ?

Are you not confident of your soldering skills
I was going to post the obvious in reply to the op, as in least amount of joints in the pipe work (and as it's an island there's a good chance it could be done in one length without joints) and pressure test before hand, but assumed that was a given
How far do you go with regards to pipes in stud or behind kitchen units etc, do you use pipe in pipe everywhere
As for your comment about gas regs, really!

As for showers being different, according to you it would need the same consideration, or do you just pick and chose when to follow the regs
Seems a bit hypocritical to me

 

[chris watkins]

you said all pipes must be accessible, water mains arnt

Inside they are, would be a bit difficult outside in the street.

Info for you & Jonny
R7.1
Detailed guidance on concealed fittings cannot be given for every circumstance likely to be encountered. Several illustrative examples are shown in Diagrams G7.1a to G7.1f and G7.1g to G7.1m. These are based on the principles:
a. That enclosure within chases and ducts can be permitted as long as leaks would become apparent and the section of pipe could be exposed by the removal of covers or superficial surface finishes (tiles or screeded finish, etc), or the pipe could be withdrawn for repair.
b. That particular care should be taken where continuous flooring such as chipboard is laid. Properly formed openings with removable covers should be provided to give adequate access for inspection and dismantling of pipe joints and for removal of sections of pipe.
The bedding of any pipe and associated pipe joints forming part of a closed circuit system of underfloor space heating in screed or in a properly formed chase in a wall or solid floor which is subsequently plastered or screeded is generally acceptable if the pipe and joints can be exposed for repair or replacement by removing the surface layers of plaster or screed.
Where pipes are located in a chase within a solid wall or floor, adequate room for expansion and contraction should be included and only a minimum number of fittings should be located within the chase (see Diagrams G7.1c and G7.1k). Pipes located in a chase within a solid floor are generally only permissible for heating pipes and should not be concreted in or the chase filled with screeding material (see Diagram G7.1c). Always seek the advice of the local water supplier before locating pipes in chases.
Where pipes are installed within a purpose made duct (see Diagram G7.1b) the pipe should be capable of being withdrawn for inspection and therefore no self anchoring fittings such as bends or branches can be incorporated unless the duct has a removable cover which will allow the pipes to be inspected and replaced if necessary.
Where pipes are located beneath continuous chipboard floors (see Diagram G7.1d), provision for access to the pipework should be provided at the time of installation as to cut sections of the floor out at a later date could result in damage to the pipework. The pipework below a chipboard floor or behind a plasterboard wall will also be susceptible to damage from nails or screws (see Diagrams G7.1d, G7.1h and G7.1l).
All pipes located in areas where subsequent inspection will be difficult or impracticable should be pressure tested before being concealed.
Where the pipe is installed within the internal leaf of an external wall, frost protection measures may be required (see Diagrams G7.1g, G7.1h, G7.1i and G7.1k).

 

[chris watkins]

Are you not confident of your soldering skills
I was going to post the obvious in reply to the op, as in least amount of joints in the pipe work (and as it's an island there's a good chance it could be done in one length without joints) and pressure test before hand, but assumed that was a given
How far do you go with regards to pipes in stud or behind kitchen units etc, do you use pipe in pipe everywhere
As for your comment about gas regs, really!

As for showers being different, according to you it would need the same consideration, or do you just pick and chose when to follow the regs
Seems a bit hypocritical to me

Info for you above from the Water Regs Guide suggest you get yourself a copy, there is no good having a go at me if you don't understand them.

 

[ShaunCorbs]

thats only if there is joints in the wall/floor

"The pipework is laid as a continuous loop without joints; and
all connections are above floor level and accessible; and
all materials are suitable for such installations: copper pipework
would be required to be protected for example by means of a
plastic coating. "

 

[tamz]

Best practice is to use a manifold and separate PIP feeds to each appliance. Doesn't cost much more to do it right.

 

[verdigrey]

Thanks everyone for your helpfull info .