Pex manifold system install#

I ran a 1' PEX main to all floors serving a manifold on each floor.

I originally thought I'd do a viega home run system, but based on the amount of vertical travel each line would be, I switched to main and manifold system to save on material and labour. In my current build I have 3 floors + basement.

In my best guess without doing any calcs, and based on big Gary's material, Your wait times for hot water would be minimal in a home run system vs a trunk system without a recirc. I'd say it would be easier to splurge on the central manifold and run individual lines in the attic. Based on your floor plan, you don't have many fixtures and they're all very close to the utility room. Also you can't or would be hard pressed to insulate the hot lines. Good practice in slab would be to create abs conduits with no lips to be able to feed/pull the PEX. Don't bother with plumbing in the slab since you can run it in the attic. I like plumbery so I thought I'd chime in.ġ. You never want to use tandem breakers unless you have to, and you can use GFCI breakers instead of receptacles for better long-term reliability. There is little, if any, cost difference, and they’re similar in physical size. Some friendly advice from an EE: use a 40 space breaker panel instead of a 30 space. I don’t like using fittings that require a gasket in any concealed locations. I’m not sure I trust shark bite fittings over the long term either. One last thing: make sure to use the metal compression ring connectors and not the plastic snap rings. The relatively short pipe runs combined with the smaller diameter required for the single fixture pipe runs will keep hot water wait time to a minimum for everything served by the manifold. If you keep the tap length for the shower short, you can always add a recirculating system on that one long run later, but you get the convenience of the manifold for everything else. I’d tee the shower and sink in the master bath off of a single pipe run for each of the hot and cold lines. In your particular layout, I’d use a manifold for everything (both hot and cold) except for the master bath. I would also not put any plumbing in any exterior walls. I would absolutely NOT run any lines in the slab unless you’re putting in radiant heating pipe.

Pex manifold system install#

The trunk line might be less total labor to install due to fewer hangers and holes being needed. You could potentially use a manifold for some fixtures and maybe a “trunk” line for the most distant two fixtures (like a toilet and sink, for example), to reduce the total amount of pipe.

If all your fixtures are approximately equidistant from the water heater, or if they’re all randomly distributed around the floor plan, then a manifold probably makes the most sense.Ĭold water is similar, but with no consideration for a recirculating system. A trunk line will probably require less total pipe insulation, and might be less work to install depending on the particular layout. Trunk lines also work well when all the fixtures are in an approximate straight line. Trunk lines tend to make sense when the hot water heater will be installed at one side of the house and won’t be centrally located. Hot water on a main line makes a recirculating system possible, but will also make it take longer for water to get hot at the farthest fixture since you will likely have a larger diameter trunk line. My favorite mechanical contractor at work would tell you that manifolds are awesome, and that they let plumbers work like electricians turning off only what they’re working on and not the entire house.