Thanks to all those who have helped thus far. I have decided I will move forward with repiping my house with Pex, but I have a couple of planning questions.

1) What size PEX should I use? I am thinking 1" from the main, 3/4" branches and then 1/2" to the fixtures? Does that make sense?

2) What is the best and most trusted/secure way to make the connections? Crimping? Compression?

3) I do not know how to sweat copper joints, but I will be connecting to copper in a number of places. What is the best way to connect PEX to copper without soldering? Most of these connections will be behind the walls.

4) Just a little nervous about running the PEX in the attic. I live in Washington, DC where it gets cold in the winter. The attic is of course unheated. Is it sufficient to insulate the pex with foam insulation? Currently the attic is uninsulated entirely, but I will be insulating it with fiberglass batting, would I want the pipes to run between two layers in the insulation? Under all the insulation? Above the insulation?

5) Finally, how often do I need to attach the Pex to a stud, etc. If I can manage to run the piping from my attic all the way to the basement utility room (two floors down) without having to open a wall, and therefore only attaching at the top and bottom of the run, is that OK?

Thanks!

Stubits,
The sizes you suggest sound right, but you would normally use whatever size you might use in CPVC pipe, if that helps.
I like compression fittings, but crimp rings have their place (tight fits etc.) and they are less expensive.
Attaching to copper will most likely involve sweating on a barb fitting for the PEX.
PEX will not freeze and burst, but insulating will keep the water flowing, especially in an attic, I would think. Keep your hangers loose, as PEX changes size 1.1" per 100' per every degree temp rise, so it needs to be able to move, or it will make noise.
Also, check with the manufacturer of the PEX you are using for the proper fittings. PEX is not yet made to a standard, (Although some are more or less to a voluntary standard) so the fittings from one brand may not fit another!

Thanks so much for the info. Very much appreciated.

Are there any alternatives to sweating the fittings onto copper? Compression? Crimp? Sharkbite?

All of the above but lets be clear, Sharkbite is a brand name and not a type of clamping. Watts and others also make similar fittings that slip into place and hold your connections. Compression should not be enclosed in a wall cavity but most codes will allow a Sharkbite or its equivalent.

Ballenger:

Thanks for the clarification. I am confident you are comfortable sweating copper joints, but what is the best, most secure option otherwise?

Also, any thoughts on the other questions? Are you in agreement with Stevens 62?

Thanks!

Steven seems on the money. You can crimp a PEX line but the crimper can run you $120 and its not always cost effective to try to rent them. Sharkbite connector are aound $5 each but no tools required, that's my route.

OK, so you are saying I could actually do the whole repiping using sharkbites?

I was planning to crimp pex to pex and just use the sharkbites for pex to copper.

Sharkbites hold up over the long run? This will be a whole house repipe.

Also, how often does pex need to be tied down? One of the major runs involves going from my basement to my attic, probably about 40 ft or so, and it is possible I would just connect it at the top and bottom of the run, is that OK? Will the pex flop around or make noise?

I think we need some of our plumbers to come on board regarding how longShakebites are good, I have only used them for about 5 years but Tom and Mark probably know better. I'll connect them to this question. On your last question, every 10' would be my approach.

I guess another question might be, how tough is it to learn how to sweat pipes? I guess that would be the best approach, and in fact, there are only really 5, maybe 7, pex to copper connections?

Is it a skill I can learn? I hear if it works, it works, if it doesn't, you know right away, right?

Local codes may have a distance in mind for attachment, but it could conceivably go 40' up with attachment top & bottom.
The noise comes from it being confined but not immobilized, especially on the hot water side. If it has room to grow without rubbing much or bumping, it will make less noise. If it is confined it will tend to "creak" as it slowly slips past whatever is confining it, but it shouldn't flop as it is fairly stiff.
I like the idea of the Sharkbites, but never used them.

I sent Tom and Mark a note but they are both offline at present. Sweating cooper isn't really rocket science. Clean the inisde of the female and outside of the male with a round brush or emery cloth. Apply flux to both, slide together. I'd recommend a cheap propane torch but when you buy your solder don't get electrical solder, buy plumbing solder. They look alike but aren't. You can also buy connectors that already have a rinfg of solder inside them. Heat the connection by directing your flame to the female fitting about a half inch away from the actual joint. Touch your solder to the joint and tap a few times until you see it starts to melt, remove the flame and feed solder in and around the joint until it wicks around the joint, wipe with a rag. When you are ready to test all of your connections have a friend or two help you watch for leaks and/or drips. If you have a leak all the water needs to be removed from the area to resolder. I am not a licensed plumber so my approach my not be accepted by all but when I get a leaker I first try just reheating and adding a touch more solder. Most plumbers would likely tell you to disassemble, clean and start over. I'm just too old to do that.

Guys, this info in invaluable, I feel great about this project. We just bought our first home and I have been loving the opportunities to get my hands dirty.

Thanks.

I look forward to Tom and Mark's input!

Stubits...

Bob asked me to pop over and see if I could help a bit.

Sharkbite fittings are good for repairs and for some transitions but I would not rely on them for whole house transitioning... otherwise sweating/soldering is best overal.l

It is not hard to solder... just takes a little practice.. glad to talk you through the basics if you want.

In fact, if you will be stubbing pex pipe into a room you will most likely want to transition over to copper pipe before stubbing into room so you can use the more traditional fittings/shutoffs available at home depot, etc... AND you won't have to stress the tubing trying to bend it to 90 degrees (inside wall this can be hard with pex.. so we transition over to copper then use copper 90 to stub into room) and you will have something rigid to attach a clip/hanger too.

PEX piping must not go any closer than 18-24" near any appliance that heats water... this means water heater and boiler. You will need to transition using copper fittings here as well.

Check out this link for a little more info. On PEX systems:

AOL Search (http://search.aol.com/aol/imageDetails?invocationType=imageDetails&query=viega+pex+plumbing+tools&img=http%3A%2F%2Fwww.pexinfo.com%2Fimages%2Ftoolde crimper-thumb.jpg&site=&host=http%3A%2F%2Fwww.pexinfo.com%2F&width=74&height=61&thumbUrl=http%3A%2F%2Fimages-partners-tbn.google.com%2Fimages%3Fq%3Dtbn%3AYc_iX4knzz3EiM %3Awww.pexinfo.com%2Fimages%2Ftooldecrimper-thumb.jpg&b=image%3Fquery%3Dviega%2Bpex%2Bplumbing%2Btools%2 6page%3D3%26displayCount%3D20%26invocationType%3Dt opsearchbox.image%26clickstreamid%3D13027647896035 16134)

Also, I would not insulate the pex pipe in the attic... Instead, I would have you run the pipe so it is as close to ceiling as possible... then you will install at least 12-24" of batt insulation over the pipes. There must be no insulation between ceiling and pipe... ok? The idea is to create an insulation gradient such that the pipe is on the warm side of insulation (ceiling side) and always protected from freezing. Let me know if have questions on this...

So, let me know what you think here... I'm glad to help more if I can.

MARK

Mark-

This is EXCELLENT! Thanks so much. I think I will learn how to sweat joints, probably not a bad skill to have in general.

The advice of transitioning to copper at the stub outs is well taken. I will definitely plan on doing so, thanks!

Also, thanks for mentioning the hot water heater. I will make sure to do so.

On the insulation... thanks! This is great information and not a problem at all, as the attic is entirely uninsulated and I will be doing the insulation at the same time. I guess I will run the PEX first and then do the insulation. Now, could I insulate the PEX as well, to avoid the hot line from sweating? Or totally unnecessary?

So, not sure if you saw my earlier question about sizing, does it sound right, 1" from the main, 3/2" branches and 1/2" to the fixtures?

What are your thoughts on how often I should connect/attach the Pex.

Finally, at least this time around, do you see any trouble running PEX in the AC/Heat chase? That is to say, can I run the PEX in proximity to our AC/forced air heat ducts?

Thanks!

Hello...

If you were to insulate anything it would be the COLD water pipe as it is the cold water pipes that sweat in certain conditions... not hot water.

It cannot hurt to insulate the cold water if you think sweating could be issue.

I would not insulate the hot water as it is hot water that always freezes before cold water does and I want your hot water pipe to pick up as much heat from the room (through ceiling) as possible... just be sure to cover pipe as discussed earlier (run pex first... like you said).

Running pex system--------------------------------------------------------------------------------------------

Run 1" main and then run 3/4" pex to all fixtures (hot and cold) except the toilet... toilet can be 1/2" pex.

1/2" pex is really closer to 3/8" copper tubing as it reduces to 3/8" at all fittings... 3/4" pex is really closer to 1/2" copper tubing again, because fittings are reduced below 3/4"... so for best VOLUME for showers, etc... run 3/4". Not that 1/2" won't work.. it will... just will have a slightly smaller volume available when others use other fixtures in house.

Pex is so easy to work with I say you hang it using your own common sense. Code tells me I need to clip/hang every 6 feet or so... in my area. As Steve62 said, just don't clip/hang too stiff... allow for expansion/contraction.

I don't see any problem running these pipes in AC/HEAT chase at all... just keep pipes maximum distance from duct work and you should be fine.

SOLDERING---------------------------------------------------------------------------------------------------------

Bob already took you through basic steps... I just wanted to list it all out for you...

1) Drain pipes of water... drain to lowest fixture in home and open all faucets in house (including outside faucet)

2) Take plumber's sandcloth and clean copper tubing about an inch on end of pipe... clean very well.

3) Take cleaning brush and clean fitting(s)

4) Flux the inside of the fitting (both sides if elbow fitting or if tee fitting all three sides of tee) and flux the pipe end (about 3/4") with a flux brush and self-cleaning flux.

5) Connect fitting and pipe end together. Do not solder just one side of a fitting unless you have a pipe in the other side of fitting.. will burn other side.

6) Apply heat to fitting so the heat is drawing the solder into the fitting. Here, you will see that bubbles begin to form at the fitting... as bubbles decrease it will be time to apply LEAD-FREE SOLDER. ALWAYS apply solder to the bottom of the fitting first..then apply solder to the top of fitting.

The blue part of the flame should be about 1/4" or so from the fitting... the idea here is to heat the fitting and then draw the solder into the joint not by melting solder with flame but by heating the joint so it actually sucks up into fitting (why flame needs to be behind fitting drawing solder in).

After you have soldered joint can give it a quick, light wipe with rag if you want.

Always be sure to wear GOGGLES when soldering... especially in the beginning and when soldering where dripping solder can BOUNCE of surface and up into your face.

Practice on a few fittings first. One big trick to fitting copper tubing and soldering is to CRIMP the fitting onto the pipe using a pair of pliers... but note here that I am talking about a little crimp and then a 1/4 turn or so to lock the fitting in place...

You can also check out these websites for a video on soldering:

http://www.askthebuilder.com/How_to_Solder_Copper_Pipe_Video.shtml

http://www.schooltube.com/video/9770/Soldering-Copper-Pipe-Module

Both these guys show one side of fitting being soldered... don't do that as discussed above.

MAPPGAS (available at home depot) is best torch for homeowners... burns hot.

Also, be sure to have a FIRE EXTINGUISHER handy... just in case!

Always solder any threaded fitting first.. let cool, then apply pipe dope or teflon tape if needed (male fittings) and THEN can install and tighten using wrench/pliers.

And finally, wash the pipes after you solder them... I use baking soda and water to break down any acidic residue left from the flux!!

Let me know if/when more questions...

MARK

Mark-

This sounds fantastic.

Frankly, I was set on hiring a plumber to come in repipe, but after hanging out on here for a while I am confident I can pull this off myself. Although PEX is completely up to code here, I only found one plumber who would run it and he said that the cost of PEX and copper repipe would be the same... sounds a bit off to me given the huge cost difference in materials.

Thanks for explaining the insulation issue. I think I will avoid insulating the pipes all together, not sure if sweating would be an issue here. I will make sure to run all the pipes under the insulation.

I had no idea about the relative sizes of PEX, thanks for clarifying that; we've been living with suboptimal water pressure for months now (we just moved in), I don't want to have the same problems now.

What distance should I keep the pipes from the ductwork? The chase isn't huge, so there isn't lots of extra room. What would be the minimum?

Can you just gut check this setup for me? I can include pictures or a diagram if it will help.

At present, we effectively have two major branches, one that feeds our basement bathroom/kitchenette/laundry room/primary kitchen and the other that feeds our upstairs bathroom. The basement bathroom/kitchenette/laundry room/primary kitchen are all done and interconnected in copper, but fed off galvanized steel, I know where the main connection point is.

In the repiping, I will have 1" coming from the main to our utility closet where it will tie into our hot water heater. Additionally, there will be a 3/4" supply line running off the 1" main to the upstairs bath (via the attic) and a second 3/4" supply line running off that 1" main to the basement bathroom/kitchenette/laundry room/primary kitchen. Similarly, out of the hot water heater I'll run a 3/4" supply line to both of those locations.

Given that it is a repiping, I am not planning on using a manifold/home run system. Will this work? Will we still have good water pressure throughout? Is there anything I can/should do differently?

Stubuts, we never mentioned this but have you checlked the permit requirements in your area?

Ballenger:

Each of the plumbers I brought in, reputable, licensed, bonded and insured, indicated that they would not suggest getting a license for this work. I have confirmed that PEX is allowable under code.

I think you meant permit, not license. You can call the building department and ask that question without telling them who you are. I'm gun shy of doing work without a permit when I am fairly certain one is required.

Stubits... just maintain max. distance you can in chase and you will be fine... keep pipes from touching duct work.

I posted some soldering sites at my last post so check them out... also added more info. As you were typing your post so be sure to reread my last post... ok?

Otherwise, all sounded fine to me... ;)

Good luck!

Mark-

Yes, I noticed the instruction manual on soldering, I seriously can't thank you enough.

Bob- I agree with you. Plumbers suggested not getting a permit because the inspectors cause a lot of trouble on repiping older homes here. Also, DC won't allow homeowners to get permits for ANY plumbing work at all.

Stubits:

Many of the questions obou t PEX can be answered in the Radiant heat Instal book link I posted. Fastening, how far away etc.

Soldering - a couple of tidbits:

Damp rag.

Practice with a few fittings like an elbow with a short length of pipe with the pipe verticle and the elbow on top.

This will make it easier to get the feel, because the solder will run up hill based on capilary action. Always heat the more massive area first. e.g the fitting

By practicing, you'll get a better feel as to when to test.

The lines need to open so there is a place for gasses to go.

They must be free of water. There is a "bread trick" when things get tough and you can't seem to get the water out.

Finally:

There are heat shields. The hardware store variety isn't very good. www.smallparts.com has a really nice shield.

While the joint is cooling - DO NOT DISTURB.

There are two types of couplings. One had a dimple or a ridge and the other is straight through. The latter is a repair coupling. It allows you to but two pieces of pipe together when the ends are constrained.

Same in my area Stubits...

Nothing like encouraging people to do the right thing...huh??

Keep us posted as you go...

MARK

Wow guys, thanks! This is all so helpful. I won't be getting started on this for another couple of weeks, but this is just what I needed... and my wife is starting to resign herself to the fact that I'll be doing this, your confidence has helped.

One more quick questions... what brand of PEX do you recommend? I guess along those lines, what type of connection do you like best, compression? Crimp? Anything I should stay away from? I hear that Zurn has had some trouble.

I am a huge fan of the VIEGA system... only system I use so can't speak about other system.

Viega is a crimp with sleeve system... check it out at:

Viega | Plumbing, heating, gas, drinking water, drainage and bathroom design (http://www.viega.net/4693.htm)

Tools can be rented at local plumbing supply house... sometimes.

Which of the three, ViegaPEX & ViegaPEX Ultra or Viega FostaPEX would you suggest for this job?

I run viega fostapex for all my hot and cold water pipes. This type pipe is stiffer than ordinary pex... less difficult to handle and just looks less like spaghetti as it forms nice clean runs.

Bob has worked with zurn pex I think... wait till he pops back and see what he thinks of that...

Excellent... and what do you pay on average for 100 ft of 3/4"?

Hmmm.. don't know off the top of my head... but wayyyyyyyyy cheaper than copper... wayyyyyy cheaper!

My only price sheet for Zurn is a little old. http://www.zurn.com/images/pdf/PEXPriceGuide.pdf The big issue with Zurn was not the PEX but their brass connectors were failing premature. You can always use somebody else's fitting even though the issue was resolved in think in 2005.

Bob-

Do you use Zurn? If so, have you heard of any problems with it? I hear they have a class action lawsuit out against them.

We kind of bet each other to the punch, reread my post #31. I have no problem with their PEX but Mark does way more than me.

Bob-

Sorry to have jumped the gun, thanks for the clarification.

Stubits,

Click on the link below will give you a rough idea about the price and also there is a contact number for the pexsuply to call them for any question

FostaPEX - FostaPEX PEX-al-PEX - Viega FostaPEX - Buy FostaPEX (http://www.pexsupply.com/categories.asp?cID=767&brandid=)

T<snip>
1) What size PEX should I use? I am thinking 1" from the main, 3/4" branches and then 1/2" to the fixtures? Does that make sense?
Somebody above said use the same sizes as you would with CPVC. That's correct. If you can look at a code book you can figure out the minimum sizes required. Rule of thumb: Cold: 3/4" to the 2nd to last or last tee on the line. Hot: 3/4" to the first major use tee or use a manifold and run dedicated lines to each bathroom group, laundry, kitchen. Long runs of 3/4 waste a LOT of water until it gets hot. I've never used 1" PEX in residential domestic supplies. Usually when you have to flow that much water it is not heated. Just use PVC unless you are worried about freezing.


2) What is the best and most trusted/secure way to make the connections? Crimping? Compression?
If you aren't going to crimp, you will get a WHOLE LOT of money in the fittings. Sharkbite tees are $9 and up each around here. Crimping probably is the biggest advantage of pex. I would use CPVC if I couldn't crimp. Really, a dual nest (1/2" and 3/4") crimp tool retails for about $150 to $170 locally. That's probably still cheaper than all the compression fittings you will use in a house. If you can afford to do the job yourself, you can afford to buy the tool. Sell it on Craig's list when you are done. :) Actually now that I think of it, donate it to me, I don't own one personally, my work supplies the crimpers, but I would love one! :D

Another thing, I try hard not to use joints in concealed spaces. (Remember why we don't use Qest anymore? :rolleyes: I'm still have a lingering concern about pex too even though I use it all the time.) I like bend supports whenever possible inside walls to eliminate joints. Tees are the biggest problem. Do them in the basement or behind access panels and run continuous tubes to the stub outs.


3) I do not know how to sweat copper joints, but I will be connecting to copper in a number of places. What is the best way to connect PEX to copper without soldering? Most of these connections will be behind the walls.
Here you should learn to sweat copper. Practice on a piece of tube that you cut out. I can't quite trust even the brass 'Sharkbite' fittings for 30+ years. I hardly trust the plastic ones long term even when I can see them. I have installed a couple of sharkbites in walls when it wasn't avoidable, but I work very hard to only use them where I can get to them. Use the sweat/crimp adapters.


4) Just a little nervous about running the PEX in the attic. I live in Washington, DC where it gets cold in the winter. The attic is of course unheated. Is it sufficient to insulate the pex with foam insulation? Currently the attic is uninsulated entirely, but I will be insulating it with fiberglass batting, would I want the pipes to run between two layers in the insulation? Under all the insulation? Above the insulation?
I'd be nervous too. Put your pipes in the warmest area of the attic. Which is BELOW the insulation. Slip on foam is a very good idea. It should be required for hot lines. Buy unsplit 6' lengths at a plumbing supply house, slip it on as you go and use the split stuff for what you have to do after the pipe is installed. The good split stuff has adhesive in the joint so it stays together.


5) Finally, how often do I need to attach the Pex to a stud, etc. If I can manage to run the piping from my attic all the way to the basement utility room (two floors down) without having to open a wall, and therefore only attaching at the top and bottom of the run, is that OK?
It must be supported minimum every 32" horizontally. Hot lines work best supported every joist. I forget vertical, but it isn't a lot farther. I don't know off hand what is required for a fished run or even if that is allowed, but if you can put it in foam insulation (and DON'T stretch the stuff) so that it can't rub anything, I might try it if I knew it was supported correctly at the top. One of those 'chinese finger trap' things might work.

I mustn't have refreshed my browser enough, I missed half of the posts. I like the Wirsbo brand of pex. We use a lot of Zurn at work, it seems fine so far, just isn't as pretty. Some of the Zurn is in for 10 years and isn't giving us any trouble. Also I disagree on not insulating the hot line. The biggest problem is heat loss during use, not needing to gain heat while laying in the pipe. Also, I haven't read my code book lately, but I do think that pex must be supported much closer that what some have said. But maybe that's just the local inspectors here.

EPM

This is wonderful information. Many thanks to each of you.

I will be moving forward on this project in the next couple of weeks, after the summer heat breaks and hopefully before the cold sets in (will make working up in the attic much easier).

I think I have the sizing figured out now, I erred in my original post when I suggested using 1" from the main. I measured the current copper main today and it is only 3/4", so I will do 3/4" from the main and to each of the two major groups and then 1/2" to each fixture.

I will definitely use crimp connections. I was just curious if there was a preference between the standard crimp connection and Wirsbo's expansion connection, but it seems like everyone favors crimping. The cost of the tool is negligible in comparison with what I am saving doing this myself.

There will only be a VERY small run of pipes in the attic. I will definitely run it under the insulation, but I am definitely confused about whether to insulate. I understand insulating as a means of reducing heat loss, but I don't want to do it if it would in anyway encourage freezing. Can anyone explain this topic a bit more? Any further suggestions?

As far as supporting the PEX, a couple of questions? Does something like this, Sioux Chief 555-23 - $9.95 - Sioux Chief - Tube Talon for 1/2" & 5/8" & 3/4" PEX Tubing (Bag of 100) - 555-23 (http://www.pexsupply.com/product_dtl.asp?pID=2206&brand=Sioux%20Chief&cID=522), allow for expansion? Would this be appropriate and acceptable for use? EPM, what is the "chinese finger trap" thing you are speaking of? Any links?

Ok, and a totally new topic, what about a gravity hot water recirculating loop? How complicated would it be to install one in this application? Does it work well with PEX? I was planning on using a "mini manifold" up in the attic to split the 3/4" supply line to 1/2" lines to each supply. They make one that has 3/4" in and 3/4" out, such as this http://www.pexsupply.com/categories.asp?cID=740&brandid=, can I just run a line back down to the hot water heater?

Thanks!

This is wonderful information. Many thanks to each of you.

I will be moving forward on this project in the next couple of weeks, after the summer heat breaks and hopefully before the cold sets in (will make working up in the attic much easier).

I think I have the sizing figured out now, I erred in my original post when I suggested using 1" from the main. I measured the current copper main today and it is only 3/4", so I will do 3/4" from the main and to each of the two major groups and then 1/2" to each fixture.

I will definitely use crimp connections. I was just curious if there was a preference between the standard crimp connection and Wirsbo's expansion connection, but it seems like everyone favors crimping. The cost of the tool is negligible in comparison with what I am saving doing this myself.

There will only be a VERY small run of pipes in the attic. I will definitely run it under the insulation, but I am definitely confused about whether to insulate. I understand insulating as a means of reducing heat loss, but I don't want to do it if it would in anyway encourage freezing. Can anyone explain this topic a bit more? Any further suggestions?

As far as supporting the PEX, a couple of questions? Does something like this, Sioux Chief 555-23 - $9.95 - Sioux Chief - Tube Talon for 1/2" & 5/8" & 3/4" PEX Tubing (Bag of 100) - 555-23 (http://www.pexsupply.com/product_dtl.asp?pID=2206&brand=Sioux%20Chief&cID=522), allow for expansion? Would this be appropriate and acceptable for use? EPM, what is the "chinese finger trap" thing you are speaking of? Any links?

Ok, and a totally new topic, what about a gravity hot water recirculating loop? How complicated would it be to install one in this application? Does it work well with PEX? I was planning on using a "mini manifold" up in the attic to split the 3/4" supply line to 1/2" lines to each supply. They make one that has 3/4" in and 3/4" out, such as this http://www.pexsupply.com/categories.asp?cID=740&brandid=, can I just run a line back down to the hot water heater?

Thanks!

Gravity recirc.
I think all that's required is a check valve, ball valve and removal/reinsertion of the drain.

In the loop, you usually return the furthest fixture's hot water to the drain of the hot water heater, so a check valve is required probably at the fixture.

Then this needs to be plumbed into the drain. You need a valve and the ability todrain the recirc-loop.

You may have multiple loops. Not sure how that complicates things, but you would have to return the last fixture on every LOOP to the drain of the water heater.

Does this make sense?

You don't want the drain to supply the water, so that needs a check valve. Your return should handle the flows of all the connected fixtures in the loop.

Gravity recirc.
I think all that's required is a check valve, ball valve and removal/reinsertion of the drain.

In the loop, you usually return the furthest fixture's hot water to the drain of the hot water heater, so a check valve is required probably at the fixture.
<snip>

I really question a gravity recirc loop in this situation. If your lines are mostly vertical and straight, then yes, but unless you really chill the return line, if you have a convoluted install I don't think it will work well enough to be worth the cost of parts. Also, most garden variety check valves have enough resistance to opening that you will need a serious temperature differential to get any flow and even then it will be insufficient. And if it does work, you are creating a small in-wall and attic heating system that will continually take heat off your water heater. Think wear and tear on the elements and kWh $$.

If you want to save water (which I think is the reasonable thing to do), put a Grundfos or Taco recirculator system in and then time it to run only during the times you actually use hot water. Rather than a timer I personally prefer a momentary switch that is manually operated for 10 secs or however long it takes to bring the hot water to the end of the line, and not run the system otherwise and save both water and electricity.

If you do a recirc loop, just tee it into the cold supply above the water heater, but below the inlet shutoff valve and expansion tank. Some of the systems I maintain have sediment problems and returning the loop at the drain valve just stirs things up and makes draining the sediment out impossible. BTDT, repented and replumbed.

Those plastic pex supports that you link to are fine. Probably a bit more expensive than the individual size ones, but great otherwise.

PLEASE insulate your hot lines. It will pay for itself, especially if your hot water use is intermittent but mostly within the same hour or so block(s) of time. They will NOT freeze faster inside insulation. They will only thaw slower if they do freeze. Also the reason I recommend insulating both the hot and cold lines in the attic is because usually when run under insulation they don't get supported very well and so they can rub as they expand and contract. If against a nail or really rough surface you can imagine what will happen down the road. Also cold line sweating in unconditioned spaces can be a problem.

Hope that helps a bit. I could go into greater detail, but my wife says I spend too much time on the computer as it is. :D

EPM

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/DesignGuides/pex_designguide.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!

<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

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/DesignGuides/pex_designguide.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 (http://www.barnhillbolt.com/index.php?root=menu&level=&menu=1849&catid=74&custid=932624448)

For a general idea.

Browse the MSC Big Book (http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=3390&PARTPG=GSDRVSM&PMT4NO=55968204&PMITEM=54055744&PMCTLG=00&PMT4TP=*LTIP)

Industrial Supply Equipment from MSC Industrial Supply (http://www.mscdirect.com) 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/DesignGuides/pex_designguide.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 (http://www.engineeringtoolbox.com/pipes-tubes-d_347.html)

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.asp?cID=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!

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.asp?cID=859&brandid=

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!

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

Thanks!

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?

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?

Don't use sharkbites to do an entire house, it will be very expensive. Rent the tool to crimp. A half inch shark bite will cost you at least 5 dollars a fitting. Just crimp it's the cheapest way to go and the best.

This is from the pex installation guide. Pex pipe should be anchored down every 32 inches on a horizontal run and every 4 foot on vertical runs. Here is a link to the manual. http://www.siouxchief.com/Resource_/ProductMedia/115/PEX%20Installation%20Guide%205-05.pdf