How to Plumb a Timber Frame

[Jb9]

Hello,

I am new to this forum so hopefully folks will forgive my ignorance. I am designing a simple Timber Frame that will have 2 floors with 2 full bathrooms on the 2nd floor and 1/2 bath + washer hookup on the first floor. My goal is to create a "wet wall" for these fixtures and NOT make any notches or modifications to the Timber Frame. This wet wall will not be an exterior wall as the site is in a cold mountain town. I do want to put the kitchen/DW against an east-facing window but hope to run the drain back towards the soil stack in between a joist. Does this seem like the most elegant solution to this design? I am trying to keep the plumbing simple so that the installation will be simple and relatively inexpensive. Do any of the folks on this forum have experience with Timber Frames and the challenges that they present? I am assuming the use of a wet wall and keeping pipes parallel to floor joists are a good start. I am just trying to figure out what a reasonable distance would be for that kitchen sink. The vent stack for these fixtures is also something I will need to figure out but I bet it could simply go up and loop back to the wet wall on the 2nd floor.

Thanks,

jb9

 

[Terry]

The original timber framing didn't have indoor plumbing.
That's how it used to be done. They did have outhouses. They dug a hole in the ground for that.
Water could be carried inside with buckets and heated on the wood stove.
At least that's how we did it in our log cabin.

 

[Sponsor]

 

[BobGa]

I'm doing a similar build.
It is Sips (structural insulated panels) construction, no walls for pipes went to Studor for design assistance, they were great.
No vent pipes thru the walls or roof, no internal vent pipes all over the place.

Yes it meets code.

 

[Jadnashua]

FWIW, a plumbing system generally needs at least one atmospheric vent. An AAV will only let air in...sometimes, it needs to let air out to prevent a pressure buildup from either draining, or sewer gasses.

One issue you may have with your timber framing is that things can move some as things dry out, so movement accommodation may be wise. You certainly can tie the first floor vent to those from the second story...it needs to be done at least 42" above the floor above or 6" above the flood rim of the highest fixture, whichever is higher. The vent needs to be sized for the total fixture units connected...and, even if it may not need it for that, when it can freeze, in most places, the roof penetration generally needs to be upsized to at least 4" to help prevent it from freezing shut from condensation (hoar frost).

 

[BobGa]

That's not correct, Studor makes a unit to allow positive pressure it's called an Maxi-filtra, it is located outside after the septic tank.

With aav(s) inside where required and one maxi outside the code is met.

I went through a lot of research on this to avoid vent holes on a super tight passive solar home I building

 

[hj]

A "vent" of any kind AFTER the septic tank does NOTHING to meet the requirement for at least one vent out the roof. If it were before the tank it MIGHT do it. The required vent through the roof is normally at the "far end" of the system so it is least likely to be blocked by "flooding" in the pipe.

 

[BobGa]

That has been approved now as far as I know nationwide, in fact it was challenged in Court and deemed as meeting the requirements.

Don't take my word for for it call Studor

 

[Reach4]

That has been approved now as far as I know nationwide, in fact it was challenged in Court and deemed as meeting the requirements.

I am confident that it has not been approved nationwide. That is not how things work.

 

[Terry]

I wouldn't be able to plumb home in the Seattle area like that.
It's not even close to what the inspectors allow.

 

[BobGa]

Studor is willing to speak to any inspector they tell me if there is an question as to how it meets the code.

 

[Sjsmithjr]

That has been approved now as far as I know nationwide, in fact it was challenged in Court and deemed as meeting the requirements.

Information provided by Studor in their US Studor Engineered Products Manual does not support this statement. In the codes section of this publication they acknowledged that there are several model plumbing codes used in the US along with numerous local variations and amendments. The codes citations provided by Studor in their manual note that where allowed (IPC and IRC) "one vent stack or stack vent shall extend outdoors to the open air" (IPC 217.7 and IRC 3114.7).

The Maxi-Filtra also requires UV protection, annual inspection, and activated charcoal filter change out no less than every two years.

Don't take my word for for it call Studor

I would be more inclined to call my local building codes enforcement department. We use the 2012 IPC locally and I would have to file an appeal to use the AAVs and two-way vent as proposed. There would be a fee for filing the appeal and, of course, no guarantee that it would be approved.

Even if allowed I would have to carefully consider taking a passive system and turning it into a mechanical system that requires routine inspection and maintenance. Plumbing penetrations can be minimized in a well designed system without relying on AAVs and they can be properly sealed to minimize leakage so what are the actual energy and financial savings? I'd like to see a quantitative analysis that takes into account all of the variables.