Supporting pipes under floorboards + insulation

[kasser]

I was just wondering - combi boiler will be in the bathroom in one corner of the house and the kitchen in the opposite far, far corner. It will take ages for the hot water to reach the kitchen.

I don't think there's a way around this with a combi? The distance is what it is and there's no cylinder to run a return leg for the hot water.

 

[Aire]

Yes.
This is all bringing back memories. I had a mate who was under a floor and need to take a rest after crawling about so he hunched himself up onto his elbows and put his head up between the joists. As he leaned his head back to rest it on the side of the joist behind and it touched one of the old lead cables which was obviously leaking to earth. It gave him a fair crack and as his head flew forward his forehead hit a brad in the joist in front, lol.... Great days !

I'm laughing just imagining that. It's always funny when your colleagues hurt themsleves, some of my best laughs at work have been at the expense of others

 

[Last Plumber]

I was just wondering - combi boiler will be in the bathroom in one corner of the house and the kitchen in the opposite far, far corner. It will take ages for the hot water to reach the kitchen.

I don't think there's a way around this with a combi? The distance is what it is and there's no cylinder to run a return leg for the hot water.

Use the shortest route possible beneath the floor in 15mm and lagg it well. You probably thought that anyway?
That's all you can do really. Try it, you might be surprised how well it works.

 

[Burger]

Yes.
This is all bringing back memories. I had a mate who was under a floor and need to take a rest after crawling about so he hunched himself up onto his elbows and put his head up between the joists. As he leaned his head back to rest it on the side of the joist behind and it touched one of the old lead cables which was obviously leaking to earth. It gave him a fair crack and as his head flew forward his forehead hit a brad in the joist in front, lol.... Great days !

I bet that never made the accident book

 

[Last Plumber]

I bet that never made the accident book

No, it just made two thuds and everyone laugh!

 

[kasser]

Yes, I'll use the shortest route of course, saves me on piping too.
But I was briefly considering running the pipe in 22mm due to the distance. however, the initial pressure and flow rate at the meter is very high, so losses will be acceptable. And a 22mm pipe I realise now will have too much cold water sitting in it. Maybe run it in 8 mm .

 

[Last Plumber]

Yes, I'll use the shortest route of course, saves me on piping too.
But I was briefly considering running the pipe in 22mm due to the distance. however, the initial pressure and flow rate at the meter is very high, so losses will be acceptable. And a 22mm pipe I realise now will have too much cold water sitting in it. Maybe run it in 8 mm .

I would stick to 15mm personally.

 

[Burger]

Yes, I'll use the shortest route of course, saves me on piping too.
But I was briefly considering running the pipe in 22mm due to the distance. however, the initial pressure and flow rate at the meter is very high, so losses will be acceptable. And a 22mm pipe I realise now will have too much cold water sitting in it. Maybe run it in 8 mm .

Most are ran in 15mm, just go with the MI’s.

 

[kasser]

I agree with 15mm. There'll be just one hot water pipe in the kitchen anyway.

 

[Burger]

How big is this bungalow? 16 rads? did you mean 6?

 

[kasser]

4 bedrooms, 2 living rooms, conservatory, office, en-suite, etc. I was surprised at the number of rads too.

 

[Jerry]

No way I am lying on my back soldering pipes above my head. Plastic all the way.

If i am running perpendicular to the joist i will drill. I make up a drilling template from cardboard (for depth of wood and space between pipes) and a laser level to keep everyhting straight.

If i cannot drill when running perpendicular, then i will use Talon pipe clips with spacers and a laser again. I find an impact driver is small and quick in tight spaces. I also make up all the pipe clips before starting.

If i am running parallel, then i use Talan pipe clips on the inside of the joists or if their is not enough room, then a cheeky batternscrewed to the underside of the joists.

People are moaning about the spacing for plastic pipes. I generally add way more, especially at bends. Plastic pipe can be arguementative and needs to be wrestled into place frequesntly and the additional clips help.

As for insulation, i generally go with cheap 9mm wall. Each section is cut in between clips. If its in an area where there could be high heat loss, then i cover the expsoed clips with more insulation. Insualtion on show gets the treatment from my new pipe lagger pro cutter thingy.

 

[kasser]

People are moaning about the spacing for plastic pipes. I generally add way more, especially at bends.

Try adding way more when screwing the clips under the joists! Not easy.

You could use straight 3m of plastic pipes. Easier to work with and not much more expensive, though if you need long runs, you'll need to join them which defeats a little the advantage of using plastic.

Shouldn't your pipes in the pic be spaced further apart? 3 times hole diameter?

 

[ShaunCorbs]

Try adding way more when screwing the clips under the joists! Not easy.

You could use straight 3m of plastic pipes. Easier to work with and not much more expensive, though if you need long runs, you'll need to join them which defeats a little the advantage of using plastic.

Shouldn't your pipes in the pic be spaced further apart? 3 times hole diameter?

Correct

 

[Jerry]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

 

[ShaunCorbs]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

Especially sparkles

 

[Jerry]

Especially sparkles

Are they like twinkles? but with more glitter and unicorns?

 

[ShaunCorbs]

Are they like twinkles? but with more glitter and unicorns?

sparkies

 

[gmartine]

I've used stainless cable ties and mounts for securing heavily insulated pipe in awkward places before ... rock solid and insulate to your heart's content. A bit overkill and made for cable but it's the business.

 

[Aire]

I knew you guys would see that! Well spotted!

Yep, the pipes were not in my first choice location. The client refused to let me space them out. I have no idea why.

Truthfully, I can find it very hard to meet the drilling and notching regs. Especially when you are coming across old joists that have been ravaged by previous trades.

I wasn't aware you could go against building regs because the customer says so. I'll remember that next time I'm asked to flue the boiler out the window because they don't want a new hole drilling

 

[sailesh]

Hi folks - nice to join this forum and I wish I'd done so earlier. Some urgent advice needed please..

Our plumber has had to repipe the central heating in our Victorian house because the existing system was single pipe. He has done this using plastic pipe and push fittings. The first time we turned the heating on, the ground floor system leaked into the underfloor void at a sagging 90 degree joint that sits in the middle of circa 4 metres of unsupported pipe. I've attached a video which shows exactly what this looks like..

I'm not convinced by his argument that the pipes don't need any support and only the fitting is at fault, so to save me the roundabout discussion could anyone please point me to the relevant guidance that defines how much sag is acceptable and what the support criteria is or isn't for 22mm plastic pipe?

 

[ShaunCorbs]

Needs clips every meter and lagging

 

[gmartine]

Hi folks - nice to join this forum and I wish I'd done so earlier. Some urgent advice needed please..

Our plumber has had to repipe the central heating in our Victorian house because the existing system was single pipe. He has done this using plastic pipe and push fittings. The first time we turned the heating on, the ground floor system leaked into the underfloor void at a sagging 90 degree joint that sits in the middle of circa 4 metres of unsupported pipe. I've attached a video which shows exactly what this looks like..

I'm not convinced by his argument that the pipes d5on't need any support and only the fitting is at fault, so to save me the roundabout discussion could anyone please point me to the relevant guidance that defines how much sag is acceptable and what the support criteria is or isn't for 22mm plastic pipe?

No sag is acceptable the lazy scrot, should be clipped every 0.5m minimum for horizontal run in 22mm.

See page 19.

https://www.johnguest.com/wp-content/uploads/2019/08/RWC-JG-Speedfit-Technical-Specs-Guide.pdf

 

[exedon2]

Polypipe exactly the same 500mm horizontal 15mm every 300mm

 

[gmartine]

...and btw the fitting isn't necessary leaking because it's faulty. It's more likely to be leaking because the pipe isn't properly seated and or the fitting is under stress because of the lack of support.