I'm installing a sillcock outside my house and I'm trying to create a drainable line so it won't freeze in the winter.

Here's the setup from the outside in:

This entire run is located through a basement crawl space that gets very, very cold (freezing?) in the winter.

  1. 8" frost-free sillcock connected to sharkbite 90 degree elbow (going straight down).
  2. 1' of pex to get under floor joists
  3. Another 90 degree sharkbite elbow.
  4. 30' of pex slightly angled down. running under floor joists.
  5. Last few feet enter the heated space of basement.
  6. Finally connected to drainable ball valve

I'm concerned about the two 90 degree elbows but its the only realistic way to get from the outside of the house and then under the floor joists. Will this be a problem?

  • If you do drain the water out there's not going to be enough left to break a 90 or any other kind of fitting.
    – Ed Beal
    May 8, 2016 at 2:56
  • What about the fittings themselves? It sounds like the sharkbite fittings are only rated to 32 F? I'm also unsure how much water I will be able to drain out of the tubing but I'm trying to do my best to have a drainable line...
    – SofaKng
    May 8, 2016 at 3:15
  • The 32°F limit likely only applies to a fitting that's under pressure. If you've drained the line, there should be no danger to the fitting.
    – Tester101
    May 8, 2016 at 3:42
  • Pecx can handle freezing with water and survive because it can expand the metal 90 or other fittings can not expand. If there is very little water in the pipe there is no problem, full of water the metal parts break.
    – Ed Beal
    May 8, 2016 at 4:35
  • Why should'nt you do it with clamps and plastic fittings which could probably take more freezing and are cheeper then sharkbites? if you are sometimes working with pex then it pays to buy once a clamp and each fitting is then more then half the price of sharkbites.
    – aofkj
    May 8, 2016 at 6:41

3 Answers 3


I doubt you need the second 90 (#3) - PEX is bendable at large radius, and if you work with that, you avoid fittings that may have freeze damage (PEX itself does not mind freezing.)

If you think of it as if it was rigid pipe, you end up with a lot of fittings. If you work with its strengths, you can avoid many of those fittings, but you don't get tidy pipe-like runs.

I would be concerned with complete drainage ("slightly angled down while running under floor joists" may work for properly hung rigid pipe - pex is not rigid pipe.)

  • Thanks for the reply. You are correct that I might not need the second elbow fitting, but the bend is going to be like 70 - 80 degrees. However, I am also concerned about the first 90 degree elbow. This 90 degree elbow is actually connected to the sillcock though but I've read that Sharkbite fittings are only rated to 32 F. However, I need SOME kind of fitting to attach the pex to the sillcock ...
    – SofaKng
    May 8, 2016 at 3:13
  • If draining the line, I'd be somewhat confident that the elbow higher up at the sillcock connection would get drained. I'd likely aim that elbow at an angle, rather than straight down, to get the bend at the bottom more gentle - this leads to a slightly less direct pipe path, but is part of the "think about running flexible tube rather than rigid pipe" mindset.
    – Ecnerwal
    May 8, 2016 at 11:00

If you are concerned about freezing, then the simplest answer is to install a ball valve inside the house, where it is insulated, so that you can shut off and drain the water before it exist the house.

As for connecting to the sillcock, 1" pex is a slightly unusual size; Most sillcocks are 3/4 inch but 1/2 inch sillcocks are also fairly common, so (probably) what you want is a 1 inch barb to 3/4 inch (reducing) female threaded connector. I found an adapter from sears that could do the trick. U S BRASS CORP/ZURN-QEST QQSFC45GX 1 x 0.75 in. Barb Ringed Shank Pex Adapter. Below is picture of it, but for $17 it's not what I would choose. Also, you would need a 1" ball valve which will cost about $10-$12.

enter image description here

I think that the better solution would be to use a 1" to 3/4" reducer for $2, a 3/4" ball valve for $7 (it's a few $$ cheaper than a 1" ball valve), then a 3/4 inch barb PEX female threaded fitting for about $3. Obvioulsy, you would need some 3/4" pex and some elbows (as Ecnerwal pointed out, the alternative to fittings are bends... 3/4 inch has a tighter radius, but still, if you use a valve inside, then the issue of freezing is mute).

enter image description here

As for making connections with PEX, I like cinch clamps, but a cinch clamp tool is kind of expensive ($40-$120). Shark bite connectors are fickle; sometimes in tight quarters, there's not a better alternative. But I would hesitate to spend so much on shark bite connectors, when for the same price, I could get a new tool (that makes certain connections) which will have paid for itself on the first use (or at least by the very next use/project- over shark bites).


Would it be possible to drill the last two or three joists and just slope the PEX up into line with the sillcock? That way no 90 degree fitting at the sillcock end and everything at that end would be sloped back towards you drainable ball valve.

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