Plumbing up through grade beam?

[bfarroo]

To me this sounds like a bad idea but I wanted to get your opinions as a group. I'm roughing in the bathroom in my shop and Wisconsin requires a 3 inch main vent stack. I want to keep the stack going up one of the outside walls but the grade beam will be 14x14. If i bring the stack up the side wall it will come up through the grade beam. Is this acceptable? my other option will be to bring it up through an interior wall, across the ceiling and then up the side. This will be a bit more work but not out of the question.

My other question is also related. With the grade beam being 14" thick I'm going to probably want to run the drain pipe under that so the main drain will be 14"+ down. I'd prefer not to have to dig the rest of the drain lines down to the 14". I'm assuming it would be acceptable to drop the sink/shower/toilet drains straight down into the main drain line as this is how it would be done in a 2 story house right?

 

[zmaxmotorsports]

Whats a grade beam?

 

[ford33]

I never heard of a grade beam so I researched it on Wikipedia. It is a concrete beam that spans across two in-ground pilings and is designed to support the weight of the wall. It takes the place of a foundation in the ground.

"A grade beam or grade beam footing is a component of a building's foundation. It consists of a reinforced concrete beam that transmits the load from a bearing wall into spaced foundations such as pile caps or caissons. It is used in conditions where the surface soil’s load-bearing capacity is less than the anticipated design loads.

A grade beam differs from a wall footing because a grade beam is designed for bending and typically spans between pile caps or caissons, while a wall footing bears on soil and transmits the weight of the wall directly into the ground".

How plumbing is worked around this beam is beyond me.

 

[WWIIjeep]

Whats a grade beam?

A grade beam is a reinforced concrete structure used as a girder under a slab and above pilings or caissons.

 

[6768rogues]

I would not put a pipe as large as a 3 incher through a grade beam because I would be concerned that the penetration would be a weak point in the beam.
I would use a 3 inch pipe below the grade beam, then continue it to pick up the toilet, shower and sink. From there, continue it through an inside wall to a roof terminal. Mark it throughout construction so no nails or other fasteners are driven through it and use nail plates where base moldings, etc. will be added later after it is at a point where marking won't do anymore.
If that is not convenient, you could vent the shower and toilet, but use an air admittance valve in the sink drain (if they are allowed where you live). Make sure the shower and sink have traps even though the shower trap will be buried.

 

[bfarroo]

most on slab pole buildings built around here are done on a monolithic slab with a thickened edge or grade beam to support the building. Think of it as a mini footing that's part of the slab. Since the grade beam is 14 inches wide and the wall posts will be 3 2x6's laminated together, if I plan in bringing the vent up inside the outer wall it will be coming up through the grade beam of the slab. To me it doesn't really seam like a good idea but was just looking for some confirmation. I think I'm going to plan on the vent going up through an interior bathroom wall and then across the ceiling and up the side of the wall.

 

[plumbstupid]

Bring the vent up in the interior wall. Once you get it into the attic space it's not much work to take it where you want. You are required to have a 3" vent, you can put it on any fixture or anywhere you want,

 

[bfarroo]

I think what my plan will be is to come in under the grade beam and go to the far wall and then turn it up, going to the ceiling and across to the outside wall. The main 3 inch drain line will have a Y in it to feed the closet 90 with a piece of 4 inch attached to go up through the concrete. The sink, urinal, and shower will also connect into the main line at different points. The toilet will be close to where the main stack is and should have no problem with vent distances. I need to decide if I should run the urinal and sink down into the ground and over to the main line with a vent for each over to the main stack or run the drains horizontal across the wall and tie into the main stack where it is going up through the wall and use it as a wet vent. I'll run 2in lines for each and they will be less than 5 feet from the stack where they tie in so I think this would be good and require less digging for me. The office/bathroom area will have 8 ft ceilings in a pole building with 16 foot side walls. I want to have a storage area above the office area so I don't want the vent stack coming up in the middle of nowhere.