Mystery Pipe

[CA2DC]

Hoping someone can help.

I have two pipes coming out of my basement slab. The big iron one is obviously the sewer line, but it's the smaller one next to it (metal & then PVC) which has me confused. The smaller one comes out of the concrete slab and goes up into the basement ceiling. Above the two pipes are 1st & 2nd floor bathrooms. It's a 1936 Sears house in Arlington, VA. Given the house's age, I'm assuming it's not Radon...

[Background. We've caught 2 Norwegian rats in the house walls with traps, and since the perimeter is secure (per our exterminator), our exterminator is claiming the rats are coming up one of these two pipes. We're scheduling a sewer smoke test to determine if there's a broken sewer line pipe in the house, but before I throw down that $$ I'm hoping to determine whether this second pipe might be the rat highway.]



Any help/advice anyone can provide would be appreciated.

 

[frodo]

That pipe is a vent from ?????
I can not see the room. I am assuming you have a floor drain in that basement
or HAD a floor drain

If the rat is in the pipe, then the only way for him to get out is an opening
Buy a black light, turn out the lights and you can find the rat trail by the piss
rats are incontinent ,, i should show up as florescent blue

google black light and rats

I have a craving for popcorn for some reason

 

[CA2DC]

Thanks for your reply.

You are correct, there is a floor drain in the front right corner of the basement. That drain has a wire mesh over it, so no critters can get through.

The purpose of my post was to determine what that second, smaller pipe might be for. As mentioned, the house is over 80 yrs old and it's an original basement. The pipe exits the concrete slab floor of the basement and disappears into the basement ceiling.

So far, no rats have entered the living space in the house. We've heard them in the walls/ceiling, and caught two with traps set inside a 2nd floor access panel behind a bathtub so I don't think your black light suggestion will work in our situation, since we'd have to open up our walls and ceiling to find any florescent blue rat trails.

Any suggestions regarding the mystery pipe would be appreciated.

 

[frodo]

the smaller pipe is the vent for the floor drain [ assuming]
the larger pipe is the waste stack for upstairs

 

[Rickyman]

Disconnect this coupling and attach a shop vac hose to the pipe. Turn on the vacuum and listen near the drain.

 

[frodo]

good idea Ricky
you handle that, I am going to make some popcorn
we need some salt....got any in your lunch bucket?

 

[CA2DC]

OK, Thanks! That's something to work with. I'll see if I can get the shop vac test done this week.

A couple follow on questions:
If it's the floor drain vent (TBD), I'm assuming it's a bad idea to remove it/cap it, to prevent rodents from using it as a highway into the house? (Assuming there's a break in the pipe in the wall somewhere between the section in the photo and where it comes out of the roof.)

If I need to keep it in place for whatever reason (venting), would I need a smoke test to find a break in the walls (assuming there's a break)? Or maybe fill the pipe with mesh/steel wool, or whatever and then close it up, so that gasses can pass through but rodents are blocked?

Thanks again!