Aluminum PEX under slab or red/blue PEX tubing in attic?

[GeorgeG.]

Which is better? I'm working with a plumber to bid out the plumbing work and he said he uses the aluminum PEX under the slab with both hot and cold sides insulated. I recall 8mpg's remodel thread where he used the red/blue manifold system where the lines run up into the attic. Does anyone know if one is better than the other and why?

I'm also having a tough time figuring out how efficient an all propane house would be with propane usage. I know it's going to be based on usage but there's got to be some general rule of thumb for a family of four/sq footage. Right now I'm bidding out with just the cooktop, one tankless water heater for the master bath/kitchen, and a stub on the patio. My concern is how often or expensive it is to refill the propane tank. Would having propane ovens, a second tankless heater, and propane heating unit be an expensive mistake?

Anyone here live on propane with a wife and 2 kids that think water is free?

[fordracing19]

I havent seen the aluminum pex. My house is all pex ran in the attic. I am also all electric because I didn't want to deal with propane. I have heard horror stories on the cost to heat with it.

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[jakesford]

I would go with heatpump down here, they are pretty damn efficient... Resistance heat sucks for really cold weather, but you won't be on it too often most likely.

[GeorgeG.]

I googled the aluminum pex. Looks like an aluminum lining between two layers of pex. The plumber said it flexes better than copper.

Anyone here running their furnace on propane? Curious about its usage.

[ceyko]

I will say that PEX has come a long way, but I have to highly recommend any PEX run through wood - spend the cash to get grommets and/or put spray foam around it. My PEX has developed 5 pin hole leaks over the years since I've been here. 4 in the garage (sloppy runs, resolved now so no rubbing on wood) but one in between floors that caused several thousands of dollars in drywall and carpet damage.

Basically, make sure it's not draped over corners of wood and when run through wood - that grommets are used. I feel like anywhere this is happening any cushion/insulation will prevent major headaches down the line.

HOWEVER, the PEX I have vs the PEX you'll have seem to be different and there are several lawsuits out on the manufacturer of mine when I googled them. Now though, it's like waiting for another problem in the walls since you'll never know it's leaking until the drywall swells (which can take awhile) or a puddle develops in carpet.

With that said, as far as I know - most new builds are PEX above foundation. Even with my leaks - I still prefer what I have since it's generally fixable at home. Plus with the manifold you can control it a little better and just turn off what is the problem until you get it fixed. Also, 50 dollars in tools and parts and you can splice/repair it quickly and easily.

...in the end I feel like my PEX issues were due to poor installation mostly. Possible some fault of the PEX company, but I have to blame the installers more so.

[8mpg]

I would run pex-al-pex without any worries. Just make sure they put a wrap or foam round the lines to keep the concrete from touching the lines. Pex has been around for a long ass time. They have used it over 30 years and for some reason it is just coming back into style. Almost all houses come with pex now a days. I would ask for his pex vs copper quote though and would expect the pex to be much cheaper than copper. If it isnt, you may just go copper.

If you go pex, get a pex manifold. They are great and allow you to shut off water to just one circuit like an electrical breaker. If a single sink or toilet leak, you can isolate it and shut it off at the panel. And to the people that say you can do that already, you cant usually do that on showers or tubs which is the advantage.

[2000 vert]

Iv never had a house with plex. But i have had a propane furnace. From my personal experience i would stay away from propane and find a good heat pump system. It was crazy expensive to run and it really sucks when u run out of gas. That being said, this was about ten years ago and the system was about ten years old at the time. So the tech may be better now. I just know i will never use propane for heat again.

[8mpg]

FYI... my house is all electric and my electric bills run $70-80 a month on a 2100sqft house. I have a 15 seer heat pump and an heat pump water heater. Im sure on a new build it would be even cheaper with proper air sealing. Id skip the propane and just go electric.

[zach]

I run a heat pump setup with emergency gas fired (propane). I have 2- 2.5 ton units, house is spray foamed. I have 2 propane tankless water heaters, propane stove and cooktop.
This last year I used 150gal from Sept to Jun, that was with the mild winter. I usually use 150 gal from Jul until about Feb with a super cold winter. The propane usually costs about $2.70 gal in summer and up to $2.90 in the winter months. I have had two houses with propane and I love it.

[GeorgeG.]

Thanks, this definitely helps.