Running PVC water pipes inside walls?

[King Herald]

Is this acceptable practise, to encase the pipe inside concrete walls?

We're planning on having a house built in the Philippines, and it appears they do this all the time: hide pipes inside the walls. I am a little wary of the idea, even though I know the PVC will probably last longer than the wall does.

I'd rather run them down a convenient corner, box them in, hide them somewhere if possible but I don't want to go to that trouble if there is no reason to.

[J-Tuner]

Well if i was doing it in the UK i'd probably encase some PVC trunking, lay the pipework inside that and then put the cover on and make good. At least that way if you need to replace or get at it it wont mean totally destroying the wall ?

Just a thought

[King Herald]

J-Tuner said:

Well if i was doing it in the UK i'd probably encase some PVC trunking, lay the pipework inside that and then put the cover on and make good. At least that way if you need to replace or get at it it wont mean totally destroying the wall ?

Just a thought

Trouble is they only use single layer walls, no air gap, just hollow blocks filled with concrete and re-bar, maybe 5" thick at most. I really don't like the idea of a leak ruining a wall though, so I may insist on working in some kind of trunking where possible.

[Smiler.]

I have barrier pipe embedded in the walls at my house (previous owner).

If I was gonna do it, I'd probably run a pipe within pipe system.

Would wanna check out the sizes for fit first, but something like a 15mm pipe in a 20mm PVC-u conduit.

[andy43]

You;d have to solvent weld the joints as a minimum - I don't think BnQ's best pushfit waste system would be up to it.

[King Herald]

They use the blue PVC pipe over there, with the solvent glued fittings. About 22mm diameter is standard I think, just for water too, no central heating over there.

[paul.deitch]

Germany installs plastic pipe in walls, no trunking. Blockwork is channelled out the same as the electrics.

[King Herald]

paul.deitch said:

Germany installs plastic pipe in walls, no trunking. Blockwork is channelled out the same as the electrics.

That sounds good enough for me then, if it is good enough for the strict and Teutonic Germans.

[therealpigdog]

Just remember where they are!

I'm in a newbuild and suffered an accident when putting some shelving up in our utility room. Checked the wall for pipes and cables using one of those electronic gadgets and nothing showing so out came the drill. Guess who drilled a hole in a pvc water pipe that was running up the middle of the wall, totally undetectable.

Apparently NHBC requires that they are positioned to the edges of the wall - mine must have been a friday afternoon job

if possible, put some wire along the pipe so that you can find/avoid it later.

[amccan10]

King Herald said:

They use the blue PVC pipe over there, with the solvent glued fittings. About 22mm diameter is standard I think, just for water too, no central heating over there.

I work for a swimming pool construction company and we encase pipes in concrete all the time.

22mm O.D. diameter is fairly small, approximately 1/2"

Personally I'd try and get them to up it to 33 O.D. which is 1"

However the main thing to look at is the wall thickness of pipe, ideally the wall of the pipe should be 4.0mm thick or greater.

As the pipes will be encased the concrete may compress the pipe and it will look oval, the greater wall thickness will help to reduce this effect.

Make sure the pipe has been pressure tested, with water not air, to around 1.5bar pressure and that the pipe has been properly secured and is squared off before installation of the concrete.

This will make life a lot easier afterwards.

Oh Ideally try and use stainless fixing band, pipe brackets or similar to secure the pipe. Other materials may cause rust staining to seep through the walls.

If any of the pipes pass through the building to an external area make sure that they have a water bar, hydrotite glued to the pipe with evo stick will do the job perfectly.

This may be a little OTT for your installation but if its done correct first time you'll never have any problems in the future

Hope this helps

Andy

[Simpo Two]

Actually in NZ the pipes seem to go up the walls - kitchen taps etc stick out from them.

[King Herald]

Good advice chaps, thanks.

I hope to take photos of each wall before the finishing is done, then do some plans, so I have a record of where not to drill holes etc. I'll try to get the guys to follow some sort of practise of running pipes in logical places, near a corner etc, rather than diagonally across a whole wall ferinstance.

I'll also have a good look at the pipe they are using, make sure it is the best available, not some cheap local knock-off stuff.

Pressure testing, good idea, I hope I will be there so I can make sure it is actually done before all is encased in concrete forever, but depending on how the do it all it may not work out that way.

I work offshore 5 on, 5 off, so I'll miss a load of the work, but I'll send wifey round with a camera to keep an eye on things.