Insulating pipes

[nelliedee]

Is there any need to insulate hot and cold water pipes before laying Celotex floor slab insulation?
Surely we would be double insulating?
Nelliedee

 

[Happyplumber]

if the pipes are sitting ontop of celotex then not really it also depends on how far the hot water has to travel as well if its quite a distance then no great harm in insulating so it stays hot for longer until it reaches the point of delivery

Need a little bit more information to make a fully valid decision

 

[nelliedee]

The pipes are running on top on concrete floor slab and 100 mm celotex floor insulation will be going on top of pipes and then a 4'' screed on top of that.
We did a smaller room last year and we did insulate the pipes but I am wondering if we really needed to. I realise that the vertical pipes need insulating but its the ones laying along the floor that I am questioning as the will be buried by the 100mm floor insulation.
Nelliedee

 

[tincup]

If the hot and cold pipes are close together then heat transfer could occur. i'd insulate the hot.

 

[nelliedee]

many thanks guys

 

[Nige F]

The pipes are running on top on concrete floor slab and 100 mm celotex floor insulation will be going on top of pipes and then a 4'' screed on top of that.
Nelliedee

I wouldn`t want them laying on concrete for corrosion/abrasion reasons. I`d have 25mm celo- then pipes notched into the remaining 75 mm celo. laid over them - and a good 150mm between H+C horizontally.

 

[nelliedee]

The pipes arnt actually laying against the concrete as they are held in place by plastic clips. I can insulate round the pipes and then lay the celotex..
Thanks for all your help
Nelliedee