Any plumbers here?

[Whisky]

This is the discharge pipe for my basement sump. It’s 1 1/2 PVC and the wall you see it going through is the external wall. I cannot figure out why they ran the sump pipe then glued 2 elbows together to RAISE the exit point from the house approx 3 inches above the line running back to the sump. There is a back-flow arrester above the sump pump so this 40ft run of 1 1/2 inch PVC stays full of water at all times. I’ll admit that I’m not a plumber and maybe there is a reason for this, but it seems it would be better if the exit point was below the run so the pipe could drain fully back to the riser each time the sump ran. Trying to keep the pipe from air-locking is the only reason I can think of that it was done like this. Any thoughts?

 

[luvmysuper]

There's no reason to have the discharge pipe full of water, as the sump pump piping has a rise anyway. The horizontal line would not need to be offset to keep it full, if anything it should be downsloped.

In many places where discharge is to underground piping, folks install a freeze relief in case the discharge pipe freezes.

 

[Whisky]

There's no reason to have the discharge pipe full of water, as the sump pump piping has a rise anyway. The horizontal line would not need to be offset to keep it full, if anything it should be downsloped.

View attachment 1781544

In many places where discharge is to underground piping, folks install a freeze relief in case the discharge pipe freezes.
View attachment 1781531

That’s what I was thinking too. As long as the pump riser has water in it you have you have an air break much like a pea trap in a sink.

Are the outside freeze protectors basically an air gap? I’m considering putting one of those in from the 1 1/2 discharge pipe into the 4” drain pipe that runs down slops and drains into the woods.

 

[luvmysuper]

That’s what I was thinking too. As long as the pump riser has water in it you have you have an air break much like a pea trap in a sink.

Are the outside freeze protectors basically an air gap? I’m considering putting one of those in from the 1 1/2 discharge pipe into the 4” drain pipe that runs down slops and drains into the woods.

Yes, it's an air gap, so that if the underground pipe freezes, the sump pump will still discharge and go out the air trap. While that's not great, it's better than a solid frozen discharge line that makes the sump pump inoperable.

 

[StillShaving]

I am far from being a plumber but isn't 1-1/2 Sch 40 DWV meant more for drains. I understand that it can be pressurized but I might see it as overkill for a basement sump pump, though maybe it is handling something more than water and condensation. I don't have a sump pump but was looking at a relative's house over Christmas and they had sump pump in their basement for the AC evaporator among other reasons. I do not have a clear memory of how it was installed, but I thought it used a smaller diameter flexible line similar to Pex.

Is it wrong to think this was done by the original building crew? Maybe they may have had some mistake/miscalculation it terms where they had drilled the exit hole through the wall and running the pipe from the other side. When they did not meet up, they went with an elbow and flexible coupling. A case of prioritizing alignment of the exit and not paying enough attention when gluing up the PVC from the other end. The rise looks very purposeful, but the use of the flexible coupling is also a red flag that they may not have been so experienced/professional.

 

[Whisky]

I am far from being a plumber but isn't 1-1/2 Sch 40 DWV meant more for drains. I understand that it can be pressurized but I might see it as overkill for a basement sump pump, though maybe it is handling something more than water and condensation.

It is a drain. The sump moves gallons of water at a time, sometimes multiple times per hour. Groundwater seeps into the sump to keep the basement dry and the weeping tiles that surround the basement run into it as well to move water away from the basement. I probably shouldn’t have said pressurized, it’s more that the pipe is full all all times making it seem pressurized when a small hole develops and the pipe has to drain through it.

I’m sure the 90 was done by the original crew. It looks like they drilled the sump outflow and dryer vent at the same place in in the outside of the wall then realized it was too high. We have Hardy-plank siding so a patch would have looked bad on a new house. I’d rather have a system that drains completely and can live with a patch in the outside siding.

I’m not sure about the flexible coupling. There were a lot of strange plumbing things done in this house. We had another water leak because they used under-sink type screw/slip nut to type pea traps in all the upstairs bathtubs then covered them up in the ceiling. When I pulled the Sheetrock to find the source of the leak all of the pea trap fittings were loose and I could spin the slip nuts by hand. I think those should have been glue traps, but I’m not a plumber.

 

[luvmysuper]

It is a drain. The sump moves gallons of water at a time, sometimes multiple times per hour. Groundwater seeps into the sump to keep the basement dry and the weeping tiles that surround the basement run into it as well to move water away from the basement. I probably shouldn’t have said pressurized, it’s more that the pipe is full all all times making it seem pressurized when a small hole develops and the pipe has to drain through it.

I’m sure the 90 was done by the original crew. It looks like they drilled the sump outflow and dryer vent at the same place in in the outside of the wall then realized it was too high. We have Hardy-plank siding so a patch would have looked bad on a new house. I’d rather have a system that drains completely and can live with a patch in the outside siding.

I’m not sure about the flexible coupling. There were a lot of strange plumbing things done in this house. We had another water leak because they used under-sink type screw/slip nut to type pea traps in all the upstairs bathtubs then covered them up in the ceiling. When I pulled the Sheetrock to find the source of the leak all of the pea trap fittings were loose and I could spin the slip nuts by hand. I think those should have been glue traps, but I’m not a plumber.

P Traps should be slip nuts, and should be ACCESSIBLE.
If something plugs up or if a ring or something drops in the drain, you want to be able to get it out without cutting the drain pipe.
There ought to be panels that are removeable to access P traps.

 

[Whisky]

P Traps should be slip nuts, and should be ACCESSIBLE.
If something plugs up or if a ring or something drops in the drain, you want to be able to get it out without cutting the drain pipe.
There ought to be panels that are removeable to access P traps.

Like I said, I’m not a plumber. The pea traps under a sink are accessible, but how do you make a pea trap accessible if, like my house, a bathtub sits above the kitchen and another above the dining room. I don’t know of anyone that would want an access scuttle in the kitchen ceiling or a formal dining room ceiling. There are so many things I’m going to want done when we build our “forever” home that I’m going to drive the contractors crazy.

 

[luvmysuper]

Like I said, I’m not a plumber. The pea traps under a sink are accessible, but how do you make a pea trap accessible if, like my house, a bathtub sits above the kitchen and another above the dining room. I don’t know of anyone that would want an access scuttle in the kitchen ceiling or a formal dining room ceiling. There are so many things I’m going to want done when we build our “forever” home that I’m going to drive the contractors crazy.

Not much you can do if it is a visible ceiling area. When a P trap is enclosed and not accessible, generally slip joints are NOT used.

 

[NorthernSoul]

Like I said, I’m not a plumber. The pea traps under a sink are accessible, but how do you make a pea trap accessible if, like my house, a bathtub sits above the kitchen and another above the dining room. I don’t know of anyone that would want an access scuttle in the kitchen ceiling or a formal dining room ceiling. There are so many things I’m going to want done when we build our “forever” home that I’m going to drive the contractors crazy.

Traps under a tub can sometimes be accessed through a wall panel hidden away like in a closet space.

I think the idea behind the strange sump pump plumbing is to make sure the line is drained when the pump shuts off, to prevent freezing near the perimeter wall. There should be some slope on the exit pipe.

 

[luvmysuper]

@Whisky

Some folks use a heater / air intake duct grate in the ceiling to provide access, while hiding the fact that it is an access.

 

[Whisky]

Traps under a tub can sometimes be accessed through a wall panel hidden away like in a closet space.

I think the idea behind the strange sump pump plumbing is to make sure the line is drained when the pump shuts off, to prevent freezing near the perimeter wall.

I’ve done the access scuttle in a closet for whirlpool tub motors. So that makes sense.

I would think you’d want the pipe to drain too, but the way it’s plumbed it holds water in the pipe. I’m getting rid of the 90s, and I’ll rehang the line for 1/4inch drop per foot and stub it out where ever that comes to.

 

[Whisky]

@Whisky

Some folks use a heater / air intake duct grate in the ceiling to provide access, while hiding the fact that it is an access.

View attachment 1781902

I like that idea, especially if I could position the tubs over a hall or closet.

 

[NorthernSoul]

I would think you’d want the pipe to drain too, but the way it’s plumbed it holds water in the pipe. I’m getting rid of the 90s, and I’ll rehang the line for 1/4inch drop per foot and stub it out where ever that comes to.

Does it hold water in that section between the perimeter wall and the elbows? It seems deliberate they have kept the elbows 3 feet or so inside the wall. Water below the elbows should not freeze, and maybe intended to make the pump's life easier since it only has to lift water a little ways as it cycles fairly frequently.

 

[Whisky]

Does it hold water in that section between the perimeter wall and the elbows? It seems deliberate they have kept the elbows 3 feet or so inside the wall. Water below the elbows should not freeze, and maybe intended to make the pump's life easier since it only has to lift water a little ways as it cycles fairly frequently.

It does not hold water in that section. My thinking, maybe I’m wrong, is that pump has to work harder because it has to pump the water up a 10ft riser, across 40ish feet of already filled pipe then up and out. If the pipe isn’t full and drained completely it seems like the pump would have to work less because then it would only have to pump the water up 10ft then siphon effect would help the water drain out.

 

[NorthernSoul]

It does not hold water in that section. My thinking, maybe I’m wrong, is that pump has to work harder because it has to pump the water up a 10ft riser, across 40ish feet of already filled pipe then up and out. If the pipe isn’t full and drained completely it seems like the pump would have to work less because then it would only have to pump the water up 10ft then siphon effect would help the water drain out.

Work done by the pump is based mainly on the head, or elevation difference. Piping losses should be more or less constant. Pumping a solid column of water is mechanically smoother than a mixed column of water and air. Hopefully, that made sense.

 

[Whisky]

That does make sense. Constant pressure on the column/pump rather.