Quote:
Originally Posted by
Stubits
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.
Quote:
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.
Quote:
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.
Quote:
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.
Quote:
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
