Capped galvanized pipes above shower in attic, purpose?

[Brendan Holder]

I have a one-story house in southeast Texas that was built in 1978. The house had a horizontal attic PEX repipe 7 years ago but still has galvanized vertical drops. In both the front and back bathrooms there are galvanized pipes rising into the attic. Each is capped. Can someone explain what these are for?

 

[Twowaxhack]

The capped pipes in the attic are useless.

 

[RickFlorida]

It doesn't freeze there, right? Just curious. We sometimes repipe through the attic here in Florida but I wonder if doing that where it freezes is more risky? I didn't know in 1978 any homes used galvanized pipe. Was copper pipe only 1960's and before or it can vary from region to region? (I'm not a professional so don't see a lot of different home plumbing).

 

[Brendan Holder]

It doesn't freeze there, right? Just curious. We sometimes repipe through the attic here in Florida but I wonder if doing that where it freezes is more risky? I didn't know in 1978 any homes used galvanized pipe. Was copper pipe only 1960's and before or it can vary from region to region? (I'm not a professional so don't see a lot of different home plumbing).

Oddly we've had 2-3 deep freezes in just the last 4 years, which is very unusual. Most of the homes in my area that were built in the 70s used galvanized pipe in the attic. Why you might ask, cost. I believe it was the cheapest option back then. I recently got a reply to my inquiry from a plumber who stated that the pipes in question are air chambers, which trap air that regulates pressure that can cause waves in the pipes known as water hammer. A lot of times it will also help stop pipes from banging.

 

[Twowaxhack]

Oddly we've had 2-3 deep freezes in just the last 4 years, which is very unusual. Most of the homes in my area that were built in the 70s used galvanized pipe in the attic. Why you might ask, cost. I believe it was the cheapest option back then. I recently got a reply to my inquiry from a plumber who stated that the pipes in question are air chambers, which trap air that regulates pressure that can cause waves in the pipes known as water hammer. A lot of times it will also help stop pipes from banging.

Homemade air chambers are useless unless recharged every few weeks to a month. To recharge, the water is turned off and drained. Then the water is turned back on. Air always goes to the top of a plumbing system.

It’s really a bad idea,it creates a dead end of stagnant water.