PEX vs Copper
PEX vs Copper
(OP)
I have been asked by several contractors to approve the use of PEX for domestic water piping in a commerical food/beverage installation. Piping will be hot, cold and filtered water. Filtered water may be re-mineralized RO. Piping will be run above and below grade. Contractors are saying the material and labor is less expensive. My questions:
1. Is this material suitable for this application?
2. If so, what are the installation concerns?
3. Is it less expensive overall?
My big concern is installation and sloppy connections. Assume that construction supervision may be lax and testing may be sloppy.
Thanks,
Dan
1. Is this material suitable for this application?
2. If so, what are the installation concerns?
3. Is it less expensive overall?
My big concern is installation and sloppy connections. Assume that construction supervision may be lax and testing may be sloppy.
Thanks,
Dan





RE: PEX vs Copper
Don Phillips
http://worthingtonengineering.com
RE: PEX vs Copper
To answer your first question you must think about how long the runs will be. how will you insulate it?
Second answer is that it does tend to look very sloppy, especially if using fire rated wirsbo, as it does not like to be straight. pex is easier than copper as it is much more forgiving, but that may be a bad thing as it could result in sloppiness by the worker, (easier work means less concentration which means, "whoops i for got to clamp that coupling, now we have a big mess.) Also it is harder to fix a leaky joint, but not a lot harder.
pex is definitely cheaper than copper, but the fire proof stuff is more expensive, but still not as expensive as copper.
So basically if it is a building larger than a big house go with copper, but if it is a small ommercial building is really see no problem with pex.
RE: PEX vs Copper
I like it as it feels like a bridge between traditional copper and sloppy PEX.
http://www.ipexinc.com/
RE: PEX vs Copper
Don Phillips
http://worthingtonengineering.com
RE: PEX vs Copper
Seems a very silly rule on first glance. Perhaps someone could explain what the fire/building code officials are after in making such a rule?! Are they worried about the pipe itself being a firespread risk? No risk of that with PEX- it's no more flammable than any wood product, surely.
PEX, particularly the non-composite stuff (ie. without the aluminum core) seems to me to be the definition of "fit for purpose" for potable water: PEX is durable, easy to install, totally corrosion immune in the run of the line, damage-resistant, freeze-resistant without bursting, and properly installed, comparatively free of joints in hidden spaces. Theres at least 50 years of installed base experience with it, so there's no need to worry about it becoming another polyisobutylene fiasco. It saves significantly on both labour and materials during the install relative to copper. I did the rough-in for the hot and cold water systems to a kitchen and bath in my house addition using homerun Wirsbo (Uponor) PEX in about 2 hours and it was 100% leak tight first time- it would have taken me days using sweat-soldered copper. The only downside is the cost of the tooling if you're a DIYer.
Some plumbers love it because it's fast and cheap. Others hate it because it takes the "craftsmanship" out of their work and "looks sloppy" because not everything is plumb and level when you're done. They tend to prefer the PEX-Al-PEX composite because it can be bent to look like pipe.
RE: PEX vs Copper
I've considered it for temporary sight glasses on tanks, but I haven't been able to determine its resistance to chemical attack from petroleum products (the literature I can find is all about corrosion resistance and applicability to potable water service).
David
RE: PEX vs Copper
Plastics - not just water lines but electrical conduit, wire, low voltage cables, etc. do not have to be fireproof, just non-combustible, like copper, steel, etc. Plastic pipes will become fuel that feeds a fire or generate a tremendous amount of smoke, which tend to hurt more people than flames.
The intent is to limit the hazard as buildings grow larger. Similarly, in addition to the 5 types of construction, the structural elements are either protected or not. For unlimited height and area buildings - which allow high-rise buildings to be built per the codes - the columns, beams, slabs, etc. may be have to be fire-resistant so that a burning building continues to stand for 1, 2, or even 3 hours.
Hopefully, that explains the intent of some of these code restrictions. Many lives were lost over many decades in horrific fires that led to the formation of these codes as we know them today.
Don Phillips
http://worthingtonengineering.com