Plumbing under floor

[akist]

Hi everyone,

We are building a garage conversion into an annexe, with a boiler, a few radiators, kitchen and bathroom with shower.

The floor is currently a concrete slab, on top of which we will install 100mm celotex and 65mm screed.

I have had a few suggestions for routing the pipework for CH and HW. From the roof down into the various rooms, or from the floor up. It has been suggested that the pipework gets fitted and fixed straight onto the existing concrete slab, before the insulation and the top screed.

What is the best way to route all the pipework?

 

[KenGMac]

akist, good evening.

if it were me? i would go for bottom up

But?

Ensure that the pipework is lagged and in some sort of ducting, such as plastic piping of suitable diameter? if the pipes are in say? plastic piping it gives you a chance of getting at them if anything goes leaky. Do not embed the pipes direct into the Concrete.

[suggest you have a search in here --search is top right -- for pipe work leaks in embedded concrete]

If you come top down, there is an outside possibility of frost damage in a vented loft? and, to me the largest drawback are the drops and trying to conceal them? As for frost damage I see loads of so called top down escapes of water, i believe that escaping water top down spreads further and faster than bottom up?

As stated this would be my preference?

Ken.

 

[akist]

Hello

Do we pass the pipes under the screed and over the 100mm insulation, or under the insulation and straight over the concrete slab? I think if we place the pipes straight over the concrete we will lose a lot of heat into the floor.

If we use plastic pipes even inside ducting, we will not be able to pull them out unless there are absolutely no connections under the floor.

Am I understanding this correctly?

 

[Keithmac]

I suppose you've got to weight up if it's easier to rip floor up or pull ceiling down if you have an issue/ leak.