PEX suport requiments

Robert_H

Two questions:

1.    I have 4 tubes of PEX (ROTH PEX-Pert) running up a wall cavity to a radiant ceiling (7' height). To fix an infiltration problem I had to open the wall all the way up I have access to the pex.  Since I’m in the wall should I secure the pex or just leave it free?



2.    In general when running radiant pex around my basement to heat loads what is the minimum support spacing?

Ironman

Pex?

Pex-al-pex or type A or C pex?



Pex-al-pex 8 ft. Max. Other non Al types, 32 inches max. Horizontally. Not sure on vertical, but the hotter the water, the more like spaghetti non Al pex becomes. Use good judgement.

Robert_H

PEX b

Bob, Its PEX b.

Thanks for replying

SWEI

Buy some sections

of steel stud track -- the stuff that goes at the bottom of the wall.  Hang it from the joists using threaded rod.  The 2-1/2" stuff will hold a pair of small insulated PEX lines just about perfectly.  Zip ties (black, UV resistant) will keep them in place.

Robert_H

Low Overhead

Nice trick SWEI But I already cant stand up in most of my basement.  I don't know why they couldn't run a couple more courses of stone as there is plenty of it lying around the property!

Dave H_2

Pex Support

Most code bodies follow what the manufacturers suggest;

32" on the horizontal

4 feet on the vertical.



With that being said, check with local codes. I have run into some areas of the country where they may require different.



Dave H.

Mark Eatherton

Its more than just support...

PEX has a high coefficients of expansion. 1.1" per 100 foot length per 10 degree F change in temperature to be exact.



So for a 2 story run, going from 70 to 140 degrees F, it will grow 1.1 X .16 X 7 = 1.25 inches. If this significant growth is allowed to go where it wants to go, then it will most probably make a lot of noise when doing so due to rubbing on floor joists etc. I like to control the direction of growth, and accommodate it to keep it as silent as possible. Anchor it on the top and bottom of the run, and leave a large loop in the middle to accept expansion and contraction, thereby keeping the tubing silent.



Support doesn't necessarily mean "anchored". It can be a guide that allows the growing tube to glide back and forth. When I "anchor" the pipe, I am truly clamping down on it to keep it locked into that position. For example, with 3/4" PEX, I will take a 2 X 4 block, of whatever length is necessary and drill a 1" hole through the largest side of the wood. I will then cut the board in the center of the hole so I have two halves of my "clamp". I will wrap this around the PEX, and screw to halves together thereby cinching the tubing to the wood, and can then screw the clamp to the structure to anchor it. This way, I control WHERE the expansion grows to and can keep it quiet.



Patent anyone? :-)



ME

Gordy

Not a bad jig

For a PHD Hydronicist :-)). Now why have plumbers not performed jig maneuver? Well most plumbers.

Robert_H

Good stuff Mark!

The gears are turning...