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massplumber2008 · Oct 1, 2008, 04:17 AM

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

Stubits · Oct 1, 2008, 07:33 AM

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

massplumber2008 · Oct 1, 2008, 10:56 AM

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...

KISS · Oct 1, 2008, 11:59 AM

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

massplumber2008 · Oct 1, 2008, 05:37 PM

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

Stubits · Oct 3, 2008, 08:23 AM

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!

EPMiller · Oct 3, 2008, 09:38 AM

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.

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!)

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?

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

massplumber2008 · Oct 4, 2008, 04:03 AM

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...

Stubits · Oct 6, 2008, 10:26 AM

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.

Stubits · Oct 6, 2008, 12:47 PM

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

Thanks!

massplumber2008 · Oct 6, 2008, 01:33 PM

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

Stubits · Oct 6, 2008, 01:34 PM

Mark, thanks!

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

massplumber2008 · Oct 6, 2008, 01:36 PM

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!

Stubits · Oct 14, 2008, 07:11 AM

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!

steven62 · Oct 14, 2008, 07:35 AM

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.

KISS · Oct 14, 2008, 08:26 AM

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.

Stubits · Oct 14, 2008, 08:28 AM

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)

ballengerb1 · Oct 14, 2008, 08:41 AM

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

Stubits · Oct 14, 2008, 08:44 AM

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.

b1s · Nov 3, 2008, 09:36 AM

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,