Copper tees (soldered) through joist

smallsteve · Jun 27, 2020

Considering many options for dealing with plastic pipe / fittings under a tiled floor, which are difficult to get to because they sit very close to the top of a brick wall i.e. extremely limited access through ceiling downstairs! The floor will ultimately be tiled. There are 4 x 22mm-to-10mm tees that then go through one or more joists, but i am considering changing to 22-to-15 tees - see pic.
At the mo i am favouring copper using Yorkshire fittings and it it got me wondering how you would install 22-15 tees through a joist i.e. soldering joints going through a joist that then require further soldering on the other side of the joist, without burning anything? i have looked around on the web and only find info relating to notching / drilling regs, which i already know about.
Is it the case that it will be a non-issue as long as you are careful and dampen-down and use mats, or do you have to take the pipe away from the joist and then double-back to go through, a bit like seen in the picture?
Only done a small amount of soldering about 20-years ago and so i may be asking a dumb-bum question! Apologies if so. :-/

steadyon · Jun 27, 2020

1. You will obviously need access both sides of the joist.
2. If you dampen, use heat guards etc. you shouldn't have to fit the loops, as shown in the left hand 10 mm pipes. Wet down the joists and anything which could burn, use folded aluminium cooking foil to make extra heat shields to fit specific places.(fold 4 times at least). Use commercial heat shields as well, and have a couple of buckets of water to hand, and don't leave until at least an hour after soldering.
3. If you are replacing all in copper:
3a. Consider making up a manifold with 4 off 22, 15, 22 tees. Then you could fit the 15 mm pipes to one side, move the assembly to the other side (i.e. further from the joist), solder that side, then move the assembly back with the now soldered 15 mm pipes going further through the joist, solder the other side's 15 mm pipes, then join the 22 mm ends of the manifold to the rest of the pipework.
3b. If you go for the manifold approach it would preclude the use of Yorkshire fittings, you'd have to use end feed.
3c. I'd guess you would need to use a pipe bender to get the 15 mm to run exactly as you want it to.
4. If you don't like the manifold approach, just use Yorkshire fittings, flux and dry assemble it all, then solder in one go.
5. If you are not confident with the soldering, get some scrap tube and a few fittings and practice until you've got the knack back again.

smallsteve · Jun 27, 2020

steadyon said:
1. You will obviously need access both sides of the joist.
2. If you dampen, use heat guards etc. you shouldn't have to fit the loops, as shown in the left hand 10 mm pipes. Wet down the joists and anything which could burn, use folded aluminium cooking foil to make extra heat shields to fit specific places.(fold 4 times at least). Use commercial heat shields as well, and have a couple of buckets of water to hand, and don't leave until at least an hour after soldering.
3. If you are replacing all in copper:
3a. Consider making up a manifold with 4 off 22, 15, 22 tees. Then you could fit the 15 mm pipes to one side, move the assembly to the other side (i.e. further from the joist), solder that side, then move the assembly back with the now soldered 15 mm pipes going further through the joist, solder the other side's 15 mm pipes, then join the 22 mm ends of the manifold to the rest of the pipework.
3b. If you go for the manifold approach it would preclude the use of Yorkshire fittings, you'd have to use end feed.
3c. I'd guess you would need to use a pipe bender to get the 15 mm to run exactly as you want it to.
4. If you don't like the manifold approach, just use Yorkshire fittings, flux and dry assemble it all, then solder in one go.
5. If you are not confident with the soldering, get some scrap tube and a few fittings and practice until you've got the knack back again.

Appreciate the detailed response and quick turnaround.

Should be OK with soldering as i have also done a lot of PCB work with solder in my time; principles the same of course. I also have a pipe bender, as well as a spring; all the gear, no idea!

With the manifold approach, is the exlusion of yorkshires because all joints are in close proximity and have to be done at the same time, otherwise the solder on the open joint will simply run out of the open fitting?

Do they use lead solder these days on non-potable, or is it now banned all-round? Which solder / flux is the way to go?

Sorry for all the questions, which are just coming to mind as i type! TIA

steadyon · Jun 28, 2020

1. With Yorkshire, as you suggest, all three joints to each tee would have to be soldered at the same time.
2. You can use leaded solder on non-potable, but definitely not on potable. Might as well stick to lead free for all.
3. I use solder from the local plumbers' merchant. I like Powerflow Flux, its self cleaning. However, I still clean the pipe and inside of fittings with Rothenburger Rofflies for surety. Powerflow tends to make the joints stick together, which can be a pain getting angles right. Many others use Laco. Rosin cored flux as for PCB isn't suitable. Whatever you use:
3a. Flux the pipe ends only. If you flux the fittings, the flux gets pushed inside when the pipe is inserted.
3b. When all three joints per tee are cleaned and fluxed, wipe off excess flux from the outside with a damp cloth. Solder will follow the flux, so if there is excess on the outside of the joint you'll end up with a mess.
3c. Heat both pipe and fitting, keeping the torch moving. Bend a "hook" into the solder wire, and try and solder from the back (unseen side) of the joint. When the temperature is right the solder will "flash" into a silver coloured ring round the margin between pipe and fitting. Don't overheat the joint or you'll destroy the flux.
3d. Let the joint cool naturally. When cold (or almost cold), wipe the fitting and adjacent pipe ends with a wet cloth or sponge to remove any excess flux. If you don't, with a self cleaning flux the joint will turn green over time.

smallsteve · Jun 28, 2020

steadyon said:
1. With Yorkshire, as you suggest, all three joints to each tee would have to be soldered at the same time.
2. You can use leaded solder on non-potable, but definitely not on potable. Might as well stick to lead free for all.
3. I use solder from the local plumbers' merchant. I like Powerflow Flux, its self cleaning. However, I still clean the pipe and inside of fittings with Rothenburger Rofflies for surety. Powerflow tends to make the joints stick together, which can be a pain getting angles right. Many others use Laco. Rosin cored flux as for PCB isn't suitable. Whatever you use:
3a. Flux the pipe ends only. If you flux the fittings, the flux gets pushed inside when the pipe is inserted.
3b. When all three joints per tee are cleaned and fluxed, wipe off excess flux from the outside with a damp cloth. Solder will follow the flux, so if there is excess on the outside of the joint you'll end up with a mess.
3c. Heat both pipe and fitting, keeping the torch moving. Bend a "hook" into the solder wire, and try and solder from the back (unseen side) of the joint. When the temperature is right the solder will "flash" into a silver coloured ring round the margin between pipe and fitting. Don't overheat the joint or you'll destroy the flux.
3d. Let the joint cool naturally. When cold (or almost cold), wipe the fitting and adjacent pipe ends with a wet cloth or sponge to remove any excess flux. If you don't, with a self cleaning flux the joint will turn green over time.

Great stuff, many thanks.

Copper tees (soldered) through joist

smallsteve

Attachments

steadyon

smallsteve

steadyon

smallsteve

Similar plumbing topics