Hey all...

Sorry I dropped the ball on this one as I have hit PEAK heat season up here and going all out day and night!

Like I said, insulating cold line is not bad idea... and as EPM said, insulating hot line can help with heat loss. If in attic, under insulation I don't see why you can't do both here... ;)

I am in Mass... and we just don't run ANY water lines in the attic because up here... they will freeze! Run under insulation or not!

And EPM, insulation used improperly will cause pipes to freeze faster as well as to thaw slower. I don't know how many people I have seen insulate a pipe thinking it would keep it from freezing in a garage only to find that the hot water pipe freezes first and bursts the wall of the pipe.

And Stubits... PEX pipe is gaining a reputation for being able to withstand freezing temps. Without bursting... so don't worry too much about freezing pipes in your attic.. ok? I am working in extremes of weather up here and forget that not everyone experiences below zero weather conditions!

I still recommend that you run 3/4" pex to every fixture except the toilet!!

Good day all...

MARK

Mark-

Glad to hear that business is doing well. No worries at all! I am just grateful you are willing to take some of your time to help all of us out.

I think I will insulate, given that it doesn't sound like it will hurt.

Guess running the pipes in the attic still has me nervous. My sister lives up in Boston so I know just how bad your winters can get and while DC doesn't even come close, we do have occasional subfreezing nights. Do you think I will be OK? Fortunately, the pipes will actually be running pretty close to the heat ducts (they're insulated, but there should be some residual heat, no?)

Finally, can you help me to understand your admonition to use 3/4" PEX throughout? What I don't understand is that I think all the hookups are 1/2". For example, the shower valve is only 1/2". Same goes for the lavatory, right now we have braided supply line that goes 1/2" to 3/8". Should I run 3/4" and tie into the shower valve with 3/4" to 1/2" adapter?

Thanks

Hi Stubits...

I guess all depends on how well closed in your attic is. Up here a lot of homes have unheated attics that are practically open to outdoors and attics get so cold we just don't dare to take a chance and we find a way to route pipes through inside walls.

And the reason I use 3/4" pex throughout is as I explained earlier...all about VOLUME!! A 1/2" pex fitting is closer to 3/8" inside diameter...so I treat it as a 3/8" line. 3/4" fitting inside diameter is closer to 1/2" so I treat as 1/2"....

Doesn't really make a difference, however, unless you are running a couple fixtures at a time. I know if it was my shower I would run 3/4" pex and then adapt over to 1/2" copper. Can't hurt and when someone say turns on washing machine you will be glad to have any extra volume you can get!!

You could certainly run 1/2" pex to lavatories and toilets as these fixtures don't require high volume... but 3/4" only for shower... ;)

Good luck...

Hey guys:

I found this design guide on the web. Now you'll know how to design it right. Time to go to plumbing school for a while.

http://www.toolbase.org/PDF/DesignGu...esignguide.pdf

KISS

Ron... this is exactly the link I have posted before to help others... It has its place, but as summary.. in the everyday house/bathroom 3/4" pex mains work great!

That link definitely makes for some great reading... all 128 pages

Back again...

KISS, thanks so much for the guide book, it was remarkably helpful. I really benefit from pictures, charts, etc.

So, I have actually been thinking more and more about installing a manifold. I am thinking this way because in the next year or two we are planning to add another 1.5 bathrooms to the house and a new washer/dryer hookup. (Don't worry, I am not doing that work myself). So, it might be good planning to have the system in place.

So, does the manifold actually improve/help with water pressure and flow? The shut off valves are nice, but not essential to me, but it seems like it would be easier to add onto the system this way.

Mark, I am struggling because I cannot find a single manifold that has 3/4" outputs. I want to make sure we have ample flow throughout the house, especially as we grow the system. Any thoughts?

Thanks!

Quote:

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Originally Posted by Stubits

<snip>So, does the manifold actually improve/help with water pressure and flow? The shut off valves are nice, but not essential to me, but it seems like it would be easier to add onto the system this way.

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It helps with pressure, flow and economy. With a manifold you run continuous tube (no joints) from the manifold to the stub outs. Often 3/8" is used because the demand of a single fixture does not cause the flow rate to exceed the recommended maximum velocity. This is good on hot lines because you don't waste nearly as much energy running off a large volume of water before it gets hot. There is 1 gallon of water in 55 feet of 3/4" pex, but it takes 200 feet of 3/8" pex before you run off that gallon. Even 1/2" pex holds only about half the water per foot as 3/4". Now, do the math and you will see that unless you have very direct lines, using 3/4" supplies will have you waiting a good bit longer for the hot water to come (remember the 2 gpm flow rate for faucets?). Also, if you have a remote manifold and a recirculating loop, the water is always hot at the manifold. (Sorry for the edit. Did my math wrong!)

Quote:

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Mark, I am struggling because I cannot find a single manifold that has 3/4" outputs. I want to make sure we have ample flow throughout the house, especially as we grow the system. Any thoughts?

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You don't need 3/4" outlets on the manifold. See my above paragraph.

I think you're finding there is a good bit more to plumbing than "water runs downhill". :D Have a good day.

EPM

Stubits...

If you are going to use a manifold then as EPM suggested... you don't need to run 3/4" out to anything.

A manifold system is entirely different then running a 3/4" main system and branching off to pick up individual fixtures.

Very few people use the manifold system in remodeling, but overall it may be best here!

Good luck...

Great. I think I am sold on the manifold system. It will be helpful to isolate any installation problems I might encounter as well as help me to get some of the water online while I work on other parts (wife will appreciate this).

Most importantly though, thinking to the future additions, it will be easiest to add on with the manifold.

Thanks!

I am sure I'll have more questions soon.

Ok, is anyone familiar with the 2000 International Plumbing Code? Does it allow the use of PEX?

Thanks!

Hi Stubits...

Check out this link again... chapter 4.


http://www.toolbase.org/PDF/DesignGu...esignguide.pdf

It appears to me that IPC 2003 accepts use of PEX pipe.

Never hurts to check with local codes enforcement anyway!


MARK

Mark, thanks!

DC is governed by the IPC 2000, is the IPC 2003 applicable?

Most towns/cities run by the most updated version, but not always. Sorry, but you need to check locally on this or wait and see if anyone else here knows for sure!

Guys-

So, everyone has been careful to point out that PEX expands and contracts, right? So, as I drill holes to run the PEX in my studs, how much bigger should the hole be than the tubing? For example, if I use 1/2" PEX, how big should the hole be? What about for 3/8? Do I need to do anything to protect the tubing where it goes through the stud?

Thanks!

PEX expands 1.1" per 100' for every 10 degree (F) rise. So, if it was say, 3/4" PEX, make the hole an inch & that should suffice.

Check with the code enforcement agent about the use of PEX. They might even say something like, we're looking into adopting the 2003 standard within 6 months or you could apply for a varience.

I have a call into them right now, although I had one very well known plumber who was willing to use PEX (I would have used him, but he wanted to charge the same for PEX as for copper)

That would be a rich well known plumber. PEX is a cheaper material to buy and easier to install in retro work.

Exactly!

He actually does a lot of the work over at the White House... I am not sure why he even came out to my neighborhood to give a bid. Definitely in a whole other league.

That being said, I was tempted, very tempted to go with him on the copper repipe as his work is very well respected and his price wasn't outrageous.

At the end of the day though, I just don't want to have the whole house torn up to put the new pipes in. I love the plaster walls and ceilings we have now and really want to protect them.

I am in a new home (1 year old) located in Tacoma, WA. The builder J. Scott Homes in Tacoma, WA has run a 1/2" Pex Line, connecting my 2 outdoor faucets, through the attic. They have told me I have nothing to worry about, and "if it made me feel better" that I could "wrap them myself." However they said that they do not see the necessity to do so. My Wife and I have a concern about water running over our heads, through the uninsulated attic.

Questions:

1. What is the Residential Code in the Tacoma, WA 98445 area for running Pex Lines through an attic?

And, if an acceptable practice,

2. Is it recommended that I wrap them in any certain way (they are not the most accessible lines to accesss)?

Thank you,

b1s,

I can't speak to the Tacoma plumbing codes, I'm on the other side of the country.

As to the 2nd question, I wouldn't go as far as saying it is good practice, but pex will not readily rupture when frozen like other types of water supply tubing. Depending on where it is in relation to the heated space, you might be OK just covering it with a fiberglas batt laid lengthwise over the pipe. I would like to see it in the bottom half of the total insulation blanket. If it is suspend in air, then you don't have many options. If you wrap it, when it does freeze, it will take longer to thaw. If the water isn't moving, a little bit of wrap or foam sleeve insulation could be worse than none at all.

EPM

Sorry to revive this thread again!

When running PEX vertically through a stud wall, how do you handle the PEX as it passes through the bottom or top plate? How big of a hole should I drill for 1/2" or 3/8" PEX? Is there a special type of clamp? At one point in our installation we will have 7 separate lines running vertically together? I know they should be supported regularly, but how is this usually handled with so many lines? Any suggestions or tips?

Thanks!

The easiest way is pipe clamps and strut.

See Barnhill Bolt Co., Inc., Fastener Specialist

For a general idea.

Browse the MSC Big Book

Industrial Supply Equipment from MSC Industrial Supply with search terms "pipe clamp strut"

Note that there are no dimensions and I don't think the pipe clamps work with the thinner strut. 1 -5/8 is the normal size.

As for hole size, I'd say about 1/8" larger than the tube.

This actually makes perfect sense now. Thanks!

I am still concerned about the PEX running through the top and bottom plate. I know that PEX expands and contracts, right? So, is there any concern with it rubbing against the rough sur face of the top and bottom plates?

The design guide, p80 has some better options:

http://www.toolbase.org/PDF/DesignGu...esignguide.pdf

They say PEX has to be free to move. Wood, I don't think is considered a troublesome penetration. Metal, block, brick etc. should be sleaved.

Excellent. Thanks so much!

What does the guide mean when it says, "Vertical tubing shall be supported ... at the mid-floor guide between floors."?

Also, not related to tubing support, but still related to repiping. The main water line coming into the house is a threaded copper pipe. How do I determine the dimension of the pipe to make sure I get the right connector? Is it as simple as measuring the outer diameter?

You need a support/clamp at both sides of the penetration.

I'm going to take you here briefly:
Difference between Pipes and Tubes

This explains something about pipes and tubes. Things get complicated. Generally sweated copper is really a tube and not a pipe, so a 3/4" copper tube has an OD of 7/8". Refrigeration tubing is an exception.

Pipe, however has a Schedule associated with it. Most is schedule 40. It doesn't matter if it's plastic or what material, a 3/4 Schedule 40 PIPE will be 1.050" inches in OD.

On the vertical runs, where the tubing passes through the top and bottom plates, would something like this work well? I know it is meant for suspended runs of tubing, but it seems like it would work in this application as well.

http://www.pexsupply.com/categories....D=859&brandid=

Now, given that the water main is not sweated copper, but threaded copper, does it fall into the category of tubing or pipe?

Perfect support.

You can't thread tube, so it's pipe.

Ok, OK, OK, I think I am catching on now, at least a little bit. Makes sense. So, if I measure the OD of the threaded copper "pipe," I'll be able to figure out.

Great!

Quote:

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Originally Posted by Stubits

On the vertical runs, where the tubing passes through the top and bottom plates, would something like this work well? I know it is meant for suspended runs of tubing, but it seems like it would work in this application as well.

http://www.pexsupply.com/categories....D=859&brandid=

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You really shouldn't need any kind of support when passing through an upper or lower plate.

When passing vertically through a wall cavity, I generally fasten the line every two feet to an adjacent stud with a two hole pipe strap, usually only screwing one side of the clamp to avoid clamping the line to tightly so it can move naturally as the line expands and contracts -- If multiple lines are passing through, I will zip tie the other lines to the one I fastened to the stud.

Interesting idea. Is it necessary to fasten it every 2 feet vertically? What is the benefit?

Thanks!

Quote:

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Originally Posted by Stubits

Interesting idea. Is it necessary to fasten it every 2 feet vertically? What is the benefit?

Thanks!

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It is in my neck of the woods (horizontally and vertically).

It is a cleaner installation and it keeps the lines from contacting the backside of the drywall as it moves.

Great idea. I didn't realize they had the potential to move around so much! Thanks for keying me into that.

I basically have to run 7 1/2" lines, is that much to wrap up together?

Quote:

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Originally Posted by Stubits

Great idea. I didn't realize they had the potential to move around so much! Thanks for keying me into that.

I basically have to run 7 1/2" lines, is that much to wrap up together?

---

It shouldn't be too much -- Just make sure you aren't bundling hot and cold lines together.

Hmm, good point! So, should I bundle all the hot together and attach them to one stud and then bundle all the cold together and attach them to another stud?

Hi,

I just finished replacing copper and galv pipes from the street to 2 baths, 2 kitches, etc.. So here is my 2 cents...

1. I would size it as follows. 1" from the street to inside the house, Off the 1" line I would tee of 3/4" to any hose bibs, 3/4" to the hot water tank, and then reduce the 1" to 3/4" to the cold manifold. I would run a 3/4" hot from the tank to the hot manifold.. Then run 1/2" to each fixture.

2. I would use Wirsbo ProPEX with the connection rings and expander tool. You can rent the tool for $25/day. I bought one off Ebay for $265 and sold it on Craigslist for $225 two months later.

3. Sharkbites are great but they are not rated for ground contact.

4. 30"

Sorry to keep this thread alive, but many thanks to all who have offered advice and assistance.

I am curious about different options for connecting the supply lines to the actual fixtures. Currently my galvanized steel piping has a 90 with a stubout where it connects to a right angle compression shut off valve.

I have seen copper stub out for use with PEX, is this what is recommended? Are there ways to avoid using these and stick with pex all the way?

Any thoughts or suggestions would be welcome! Thanks!

Gut feeling, having never worked with PEX.

A fixture usually consists of a supply, a valve and a flex supply to fixture. I would not be a fan of everything "flopping in the wind", so to speak.

The niceest looking, easy to paintain stub, in my opinion is the elbow with ears attached to a stud within the wall.
To this a piece of threaded pipe. Can be a brass nipple or a chrome plated brass nipple depending on visibility. A cone or hinged estucheon is attached to the wall. Then the threaded angle stop attached to that.

To make a really professional job, sleave the penetrations of the drywall with PVC.

Follow where needed, pipe to sleave with fire caulk.

The only place I can think of that would not require this is shower areas behind an access panel and, of, course outdoor hose bibs.

Shutoff normally exist at the manifold, but it sure would not hurt to have one nearby when doing replairs.

To give you an example, a bit weird, though.

Shutoffs for a bathtub behind a large wooden access panel where a shelf would have to be emptied and the stuff on the floor of the closet would have to be emptied as well to gain access.

My valves are not directly behind the panel. They are in the ceiling below (suspended ceiling in basement).

They can be turned off in the basement in an emergency, They can also be turned off from inside the access panel as there is access to the valves.

When I replaced the Lavatory shutoffs. It was the long chrome plated soldered angle stop with the pipe versions, I took the opportunity to install secondary shutoffs downstairs in the ceiling with drains. At that time I anchored the pipes in place so the valves were relatively immobile.

I did the same for the toilet supply except did not replace the valve.

While I was at it, I piped the connections for a recirculating system.

Just out of curiosity, why sleave the drywall penetrations with PVC?