I'm looking to purchase the pex for a new house for myself. Basement and first floor 3 1/2" slabs and second floor is wood frame with 1 1/2" gypcrete. In shopping on line for 1/2" Pex I see huge differences in price! 2000' of 1/2" with the funny name that used to start with W and now U is $1,250. Another "off brand" is $550 for 2000'. All the ASTM's seem to be the same. What am I missing here? I don't want to throw away $650 but I certainly don't want anything but the best buried in my slabs. Is there truly a difference or is it all in marketing?

Also look at PE-RT (should be less expensive and easier to work with).

We use many brands and specifications of PEX, in Europe A, B and C. As with most products; if you are unsure of the quality it is safer to stick to the name brands e.g. Uponor, Mr. PEX, Rehau, Viega, HeatLink and yes, even Roth's PERT will do. All are more than adequate and will serve for a few lifetimes. Most are made in N. America and Europe...as it should be.

Careful of private labels and odd sizes. Most gypcrete goes over 3/8" PEX tube as you pay by the inch.

Thanks. Badger, I'm not sure what you meant by gypcrete going over 3/8 Pex?? The only other similar project I've done I put 1 1/2" of gypcrete over 1/2" pex - that was 10 years ago and it works well and has held up fine (the finish floor was 1/8" cork tiles right on the gycrete - which I plan to do again in the current project). Where there was a wet area (a shower area) I poured 3000# concrete and applied porcelain tile - again, no issues.

All our pex (unless space constrained) is 1/2" in gypcrete. Because the tubing have to meet the ASTM regs, they all look like they have the same specs but this is not necessarily true. A Kia and a BMW are both cars and both get you from A to B but...........

Don't know Mr PEX but the rest are old names in the biz

OK. A little more digging and I see I was comparing PEX-A with PEX-B - hence the massive price difference. My previous project mentioned above used PEX-A and my inclination is to go with that and spend the extra $$.

Mr. Pex has been in the biz for quite awhile too. we've been using it for years.

We used to have a pex-al-pex product from IPEX called Kitec. I used it a lot running to rads or manifolds from the boiler. They pulled it from the market because of corrosion issues where aluminum can meet the compression fittings (I have only now started to use crimp rings, never trusted them before). Early on I used Wirsbo in floor but now it is exclusively Rehau. I know it is a good tube and I don't buy over the net so my prices are competitive. What people buy is often regional whis is probably why I never heard of Mr PEX and Roth, Veiga and Heat link don't have a big presence in Ontario. Heatlink is one of the very first in North America with PEX tubing.

I believe kitec was pulled because fittings had problems and they had issues with a lot of open freshwater systems with ungrounded electricity, cost them a lot of money and they just pulled out of the market. I don't believe they had any problems with the pipe itself that had anything to do with quality of the pipe itself, just really poor applications. fittings were bad though.

Yea, they didn't really need to pull the tubing off the market. A Korean company came out with a copy of the tubing and with basically the same fitting except that there is a plastic ring separating the tube from the fitting. IPEX could have done that.

The PEX B I had priced was by Everhot - had never heard of them before. I had heard of the lawsuits years ago but I never heard just what the the technical issue was. Was it just tubing failure to the point of leakage or was it bad oxygen barrier and corrosion issues - or something else?

kitec's plumbing fittings failed. I believe they de-zincified but I can't swear to that.

I saw tubing blister issues online on a development in the northwest. they were open freshwater systems, and I believe the resolution there was that ungrounded electricity in the systems went to ground through the radiant piping and electrolysized the pipes. but again, I can't sweat to it, that's just best recollection.