Is It Good Practice / Make Sense To Fit Isolation Valves Between Floors?

[MrMiller]

Hi Folks

I'm in the process now of redoing the bathroom, as I needed to remove some lead waste piping, which has lead to removing the bath, etc.

My question now - whilst everything is out / capped - is whether I should fit some isolation valves in our kitchen below?

The pipes are boxed in but run up in a corner of our kitchen leading up to the point in this picture:-

It looks like PEX pipe has been used for the cold feed to the bathroom, whilst copper has been left in place for the hot.

I really don't like how short the PEX feeding in the cold there is and the fact that the push fit connector is half way into the floorboards (!), so adding an isolation valve below would also allow me to replace the pipe above with something a bit longer before any fixture where attached. So that would be a plus.

The hot is copper into the bathroom. You can just about see the tee for some 22mm copper which was previously feeding the bath hot tap before I removed it. Otherwise the tee has a 15mm copper piping coming off, which just runs directly into a push fit tee which has PEX feeding the sink and shower.

So, my thoughts were that if I add these isolation valves in the kitchen, I would cut the copper at that point and - same as the cold - just run PEX up into the bathroom from that point. Basically taking about 1.5m of copper piping out of the system.

So would it make sense to do this?

For me, it seems a good idea as I know if we have any problems in the future I can turn the supply off below and retain water / heating to the rest of the house as I don't have to turn off at the main.

But I'm doing that at a cost of adding a further potential failure point into the system should the isolation valves themselves start leaking.

And also, I'm presuming when this was last done the plumber left the copper feed in place up to the bathroom for a reason. I have read that PEX with hot water over a certain temp can blow if there's a problem with the boiler. Maybe it was that? But I'm figuring that there's already PEX in the bathroom anyway feeding the sink & shower, so that was always a possibility anyway... On the other hand, I could add this isolation valves and leave the copper feeding the hot up. My only real feel against that is that it may be better for every pipe / fixture in the bathroom to be plastic. I worry that the copper pipe to push fit is potentially a bigger failure point than just PEX piping and super seals. Having said that, there is a copper to push fit connection already in there and, as far as I'm aware, its been there for years and been fine.

Would much appreciate any views on whether I should be doing this as a good practice thing, and if so how, or whether I'm best just leaving it:-

1. Leave
2. Isolation valves at kitchen level with PEX running up both hot and cold.
or 3. Isolation valves, PEX on cold side but leave copper running all the way up.

Thanks.

 

[Wayners]

Good quality isolation valves are ok. If you think it may help when you get problems.

I'd rather not fit them because they can play up but the quality ones with leavers are ok.

 

[Madrab]

Best practice would be - Isolation/service valves in the same location as the outlet it services - mains stop tap (lever or other) in an easily accessible location where the mains enters the building.

Anything else is just duplication and a possible hidden failure point IMO.

 

[MrMiller]

Anything else is just duplication and a possible hidden failure point IMO.

I agree re it being at the cost of an additional potential failure point. However, if I don't add anything, I leave that piping as per the picture in an unreachable position before any first floor isolation points.

The funny thing is until I opened up the under bath can of worms this was always the situation! But now I've seen it, I'm not comfortable with these push fit connections in such inaccessible location... If a leak ever occurs there, we'd be without water to the entire house until it could be fixed.

 

[robinbanks]

Modern approach is manifold plumbing, where the main supply goes to a bank of isolation valves that service rooms (typically) or appliances (atypically). You might not want to go to that extreme of replumbing though, so maybe just fit an iso valve on an easily accessible bit of pipe before the joints you're concerned about.
Personally I think I'd do away with those multiple elbows and just replace the shortest pipe with a longer run into a compression iso valve reducing the number of joints. Plumbing typically leaks at joints, so the fewer the better. Push fit joints are very reliable when well installed though

 

[blup]

Minimise the number of connections while the floor is up, and make the new isolator accessible.

 

[MrMiller]

You might not want to go to that extreme of replumbing though, so maybe just fit an iso valve on an easily accessible bit of pipe before the joints you're concerned about.
Personally I think I'd do away with those multiple elbows...

Thanks Robin

You're right about those elbows - I've no idea why they were in place. Here's a photo of the original setup before I removed the tees for the bath tap and shower:-

So you can just about make out at the bottom that it was always like that. Maybe just to create space away from the copper hot pipe coming up for the bigger push fit connectors but really I think there was enough.

Anyway re removing those elbows and back to my OP, my problem is that bottom elbow is half way in the floorboard with no slack to pull it up. If it wasn't like that, I may well have just left but if I add an isolation valve below in the kitchen, I can have a longer, more suitable pipe starting point in the bathroom.

And if can remove those two elbows, I guess overall I have one less potential failure point but with a turn off point before the bathroom.