Shut off valve in attic?

[OneStaple]

I'm starting a bathroom remodel. The plumbing for the bathroom runs through the adjacent attic for a couple feet (see picture). I'm thinking of putting a couple ball shutoff valves there both to make renovations easier and in case I need to isolate that bathroom for future work/repairs.

The current pipes have insulation on them. I'd have to remove/expose (permanently, I think) at least a few inches to install the shut off valve. Attic is unheated. Winters around here (near DC) often get into the low 20s, if not lower on occasion.

Thoughts? Should I avoid removing insulation?

Thanks,
Tyler

 

[Cacher_Chick]

It is never good to have water lines in a space that will drop below freezing temperatures. Insulation does nothing to keep the pipes from freezing unless there is a source of heat to stop it from dropping below that temperature. The piping should be under an R-19 or better layer of attic insulation, on the warm side of the insulation.

If you want shut-offs, drop the supply piping down an interior wall and hide them inside a vanity or a built-in.

 

[Sponsor]

 

[Jadnashua]

You could bury them in the insulation right above the ceiling and they wouldn't freeze, but finding them again could be a pain! This is why it's better to have them either in the wall, or underneath the floor of that room where you can have an access panel, or put them say under the sink as suggested.

You could probably build a foam box with enough insulation around and above it, and then rely on enough heat from the room below to keep things from freezing. That would be easier to find.

 

[Plumber69]

I had a customer with frozen water lines. He put a manifold in his unheated attic. Stupidest thing I ever seen

 

[Jadnashua]

The slightest air leak, and insulation becomes a moot point.

 

[OneStaple]

Thanks all. I suspected what you said would be the answer. I first saw those lines in the attic during my renovation on a nearby bathroom, and they've made me nervous ever since. On the plus side (and I'm in no way trying to justify their location), they've managed to last about 36 years since the house was built without bursting. At least it doesn't look like repairs were ever done.

Once I do a little more demolition, I'll try to move the lines to heated space, not in the attic. They're in a weird spot though where sections of the house come together, so this could be challenging.

I'll also probably have to forgo shut off valves for that bathroom, as the lines will end up behind finished walls and under floors. Not the end of the world. Using the vanity would mean running to the opposite end of the bathroom before branching to the respective appliances.

Thanks,
Tyler