Return to the Plumbing Forum | Post a Follow-Up

Water Pressure Test Prior to Drywall and Tile

Posted by syd81 (My Page) on
Fri, Aug 1, 14 at 11:41

I'd like to test the water pressure in my new bathroom before I button up the walls. I ran 1/2 water lines and worry that the flow might not be enough. I figure I can sweat a fitting on the end of the shower lines that will accept a gauge, but I thought I would check here first to see if there is some standard or recommended method I have not heard of. What do you think?

Follow-Up Postings:

RE: Water Pressure Test Prior to Drywall and Tile

It occurs to me that pressure is not the same as volume or flow in this circumstance. Capping the line creates a closed system and the pressure will be the same throughout. So how do I measure flow? Run the water into a bucket for 1 min and then measure how much? Any help would be apreciated.

This post was edited by syd81 on Fri, Aug 1, 14 at 12:58

RE: Water Pressure Test Prior to Drywall and Tile

You are correct, you cannot measure the flow rate the way you proposed in first post.

You won't get a good approximation without the finished fixtures in place. Most of them have flow rate restrictors.

You probably need to look at what size pipe, how long, how many el's to come up with a pressure drop for a given run. That will give you a better idea

RE: Water Pressure Test Prior to Drywall and Tile

is this a "new" bathroom or a remodel of an existing?

RE: Water Pressure Test Prior to Drywall and Tile

It is a new bathroom. I ran the lines myself and didn't consider running 3/4 at the time - only later to read about problems with long runs. It is a second floor bath.

RE: Water Pressure Test Prior to Drywall and Tile

Would it be a matter of hooking up the fixture, measuring the gpm, and then comparing it to the manufacturer recommendation?

RE: Water Pressure Test Prior to Drywall and Tile

How long is the run, how many elbows, how many fixtures, what kind of pipe (pex, copper, CPVC)?

Short of doing the math... you may run into an issue if have multiple fixtures (shower, sink, toilet) on a single half inch run. What you will have is the shower changing temp when the toilet flushes, for example. Half inch is usually fine for single fixture in residential applications.

As far as a single use- you are most likely to see any problem in the tub - where the flow isn't restricted.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here