Supporting pipes under floorboards + insulation

kasser · May 6, 2019

Hi,
How do I support with clips pipes run under a floating timber ground floor? The joists are too small to notch or drill into and in any case, there's plenty of space underneath. Where do you place the pipe clips if running perpendicular to the joists?
And if plastic pipes, this means lots of clips, every 300 mm for Speedfit! Lots of floorboards going up?
I've never had to do this yet.
Now I've got a job fitting central heating in a bungalow. Pipes could go under the wooden ground floor or over in the loft. Which route would you take? What insulation would you use? Finally, how do you fit the insulation snugly around with plastic pipe clips in the way?

Brambles · May 6, 2019

Attic and down for me, but I can see the benefits of going under the floor too. Being old, if I was going under the floor, I would pipe in copper - safer from a leaking perspective, longer lasting, less clipping and fewer floorboards to lift.

For the attic route, pipe in plastic, possibly with copper droppers

Best · May 7, 2019

Copper also for me. It will require very little support.
You could still use push fit fittings to the copper pipes if you wished so to avoid difficult soldering and fire risk.

Burger · May 7, 2019

You can get spacers for talon clips, that would give space to allow for insulation. Insulation doesn’t stop freezing, just which type depends on how long before it could freeze. Also I’d say up and over, if they ever fit a difficult floor (glued laminate) then if there’s an issue it’s harder to repair.

kasser · May 7, 2019

Do you fit the pipe clips on the bottom face of the joist facing the ground, when running pipes perpendicular? I've done it before for a gas pipe, not easy and it was just a couple of clips. I can't imagine having to do that every 300mm.
I would prefer to run it up and over but it does mean using more copper where the pipes are exposed, and more pipes generally.

Burger · May 7, 2019

kasser said:
Do you fit the pipe clips on the bottom face of the joist facing the ground, when running pipes perpendicular? I've done it before for a gas pipe, not easy and it was just a couple of clips. I can't imagine having to do that every 300mm.
I would prefer to run it up and over but it does mean using more copper where the pipes are exposed, and more pipes generally.

I can’t visualise what you mean, however you could use insulation around the pipe and use nail in clips, a bit harder to do, but achievable.

kasser · May 7, 2019

CBW1982 said:
I can’t visualise what you mean, however you could use insulation around the pipe and use nail in clips, a bit harder to do, but achievable.

If the pipe runs across the joists, so underneath them, where do you fit the pipe clip? It'll have to be under the joists? So hanging off them in a way...

Burger · May 7, 2019

Ah I see what you mean now, I did try and envisage that, but was struggling. Depends on how much hammer room you have, use nail in ones, but I’d go with using copper so less spacing as opposed to every 300mm.

kasser · May 7, 2019

You can't wrap insulation around if you use the nail clips?
Copper more expensive

As the pipe won't be seen, plastic would have been ideal.

Burger · May 7, 2019

kasser said:
You can't wrap insulation around if you use the nail clips?
Copper more expensive
As the pipe won't be seen, plastic would have been ideal.

Do it before nailing and nail afterwards if possible?

kasser · May 7, 2019

I doubt the nail clip with fit over and around the insulation that's over the pipe.

Burger · May 8, 2019

kasser said:
I doubt the nail clip with fit over and around the insulation that's over the pipe.

It depends, I have managed to insulate plastic in a loft and carefully clip 15mm nail in clip. Just push hard until the clip sinks into insulation, then hammer home.

Millsy 82 · May 8, 2019

Lag the pipe with thick climaflex then strap band to the joists.

kasser · May 8, 2019

Sounds good. Something like this:
Galvanised Perforated Banding

What minimum thickness do you recommend for climaflex?

Millsy 82 · May 8, 2019

kasser said:
Sounds good. Something like this:
Galvanised Perforated Banding

What minimum thickness do you recommend for climaflex?

That's the stuff and I use 19mm wall under the floors. It's a pain to work with but it is quite firm so will protect the pipe from the banding.

Jerry · May 8, 2019

Is there a crawl space under the floor?

kasser · May 8, 2019

Yes, but I don't fancy crawling there!

Jerry · May 8, 2019

kasser said:
Yes, but I don't fancy crawling there!

Its character building

Millsy 82 · May 8, 2019

Jerry said:
Is there a crawl space under the floor?

I hate doing that.

kasser · May 8, 2019

Millsy 82 said:
I hate doing that.

Do you have to?

Millsy 82 · May 8, 2019

Every now and then if there is enough room. Sometimes it's just easier to do that then lift all the boards.

Last Plumber · May 8, 2019

My advice:-
Crawl under the floor, use Copper and clip every 3 foot (roughly). Solder the joints, watch your face and eyes for molten solder and your ear holes and nasal passages for the odd spider who might be a tad nosy......... some will stare at you like this

and some will have no fear and ask who you are and what you want.

I had an apprentice with me a while back and I was surprised at how things have changed on the health and safety front (maybe they haven't but now they get drilled with it a lot longer than we did back in 1800 and frozen to death). Anyway, here is a bit of the type of advice he would have given!!

Mains power off, use battery lamps, observe all the panic and fear over confined spaces, fill a risk assessment form in, take a suitable fire extinguisher with you and mobile phone, tie a rope around your ankles and the hatch, make sure there is someone else in the building who knows you are under there etc etc, can't really remember much else he said because I was too busy crawling under the floor to get on with it.

Lagging:-
Foam and stand off clips is best in my opinion.

Who remembers Hair felt? that used to be popular didn't it? For those who do not, it was highly flammable and very dusty/hairy to work with. You could come out looking like Chewbacca after an hour or two under there wrapping pipes with that.

ShaunCorbs · May 8, 2019

Screw to the side of the floor joists ?

kasser · May 8, 2019

What did you do with the risk assessment form???
I understand how the strap band works with the insulation-wrapped pipe. But how do you clip a pipe with insulation around? You'll have to remove a small piece to allow for the pipe clip?
Someone needs to invent a long flexible support you can slide under the floorboard, screw to the joists at each end and then slide the pipes onto it. Job done. Basically doing the job of the plasterboard ceiling supporting the pipes that you run under the first floor.

kasser · May 8, 2019

ShaunCorbs said:
Screw to the side of the floor joists ?

Only if the pipe runs parallel to it.

ShaunCorbs · May 8, 2019

kasser said:
Only if the pipe runs parallel to it.

Screw a piece of 2x2 if it’s perpendicular

ShaunCorbs · May 8, 2019

kasser said:
What did you do with the risk assessment form???
I understand how the strap band works with the insulation-wrapped pipe. But how do you clip a pipe with insulation around? You'll have to remove a small piece to allow for the pipe clip?
Someone needs to invent a long flexible support you can slide under the floorboard, screw to the joists at each end and then slide the pipes onto it. Job done. Basically doing the job of the plasterboard ceiling supporting the pipes that you run under the first floor.

You mean like this ?

Britclips® Rapid Sliding Wall Bracket

kasser · May 8, 2019

ShaunCorbs said:
Screw a piece of 2x2 if it’s perpendicular

If it's plastic I'll have to do it every 300 mm. It seems there's no other way round screwing something every 300 mm whatever support method I choose.

Last Plumber · May 8, 2019

kasser said:
What did you do with the risk assessment form???

I can only tell you he didn't like it.

You'll manage OK with it, trust me I'm a Plumber.
The foam lagging will fit around the pipe from beneath and kind of envelope the clips, depending of course on the thickness of the foam. If it is too thick then as you already said, you'll need to nip a bit out.

ShaunCorbs · May 8, 2019

kasser said:
If it's plastic I'll have to do it every 300 mm. It seems there's no other way round screwing something every 300 mm whatever support method I choose.

Use mlcp then

Last Plumber · May 8, 2019

The job is best done from under the floor otherwise you'll be moving furniture as well as lifting floorboards and carpets everywhere. If you go under, you can have it done.

Last Plumber · May 8, 2019

kasser said:
If it's plastic I'll have to do it every 300 mm. It seems there's no other way round screwing something every 300 mm whatever support method I choose.

That's one of the reasons Copper is better.

kasser · May 8, 2019

More like this:
https://www.NoLinkingToThis/p/talon...VrZPtCh00uwdAEAQYBCABEgKobfD_BwE&gclsrc=aw.ds
but much bigger and wider to accomodate insulated pipes. You screw slide it 3, 5, 10 metres long below the joists, perpendicular to them, screw it in a few places to hold it then slide all your pipes into it.

kasser · May 8, 2019

Last Plumber said:
That's one of the reasons Copper is better.

Yes, I may consider copper then despite the price, if I can finish the job sooner.

ShaunCorbs · May 8, 2019

kasser said:
More like this:
https://www.NoLinkingToThis/p/talon...VrZPtCh00uwdAEAQYBCABEgKobfD_BwE&gclsrc=aw.ds
but much bigger and wider to accomodate insulated pipes. You screw slide it 3, 5, 10 metres long below the joists, perpendicular to them, screw it in a few places to hold it then slide all your pipes into it.

Use some 100 x 25mm trunking then elec fact should have that

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