Installing new service room floor drain

[mikeyb7691]

Hello,

I am replacing an old floor drain in the service room because the original 1.5" line did not have a trap. I have two options.

1. Install a new 4" line to the main line, (8 feet away)involves breaking up existing floor.

2. Install new 1.5" line with p-trap along same path. The old path is routed to another line, possibly one leading to a shower that connects to main line.

*Also the old line is most likely connected to a vent pipe, do i need to vent the new 4" drain pipe as well?

**I have 4" drain pipe in the laundry room as well, which is just across the service room, at the lowest point in the basement.

Thanks in advance for any help,

Cheers,
Mike

 

[Matt30]

4" or 3" is best. An 1 1/2" floor drain isn't going to offer you much help in the case of a major flood

I'm not sure of your codes, but here in Canada, an 1 1/2" floor drain is not permitted....a 2" floor drain is permitted but requires venting....3" and 4" floor drains do not require vents but all floor drains require a mechanical trap primer device.

 

[Matt30]

It's also worth mentioning that floor drains are no longer permitted in rooms with oil fired boilers, oil fired hot water heaters or oil tanks

 

[mikeyb7691]

Thanks Matt, good to know!

Mechanical trap, is that for code as well? Could I redirect the water coming from the furnace humidifier to constantly fill the trap? Also If I could pick your brain for a sec, whats your opinion on cheater vents for washing machine drains?

thanks again

 

[Matt30]

Yes the trap primer is for code, but then again I don't know where you live, so I don't know what code you call under. I'm one of the few Canadian plumbers here, so my codes differ from most.

You can run the humidifier drain there, but if a permit was pulled for the work it wouldn't pass an inspection. If you ever were to sell, a house inspector could pick up on it.

Regarding the cheater vents, make sure you use an approved air admittance valve, not one of the $5 cheapies from the hardware store. If your washing machine drain is 2", it will do the job

 

[mikeyb7691]

Thanks Matt, good to know. So far four of the plumbers that came by never mentioned a trap primer.Btw i live in ontario.

 

[Matt30]

Ontario.....oddly enough you guys have your own code. I'm sure it's the same as the National Plumbing Code of Canada when it comes to the important stuff.

Section 2.4.5.5 (1)
A) Provisions shall be made for maintaining the trap seal of a floor drain by the use of a trap seal primer

B) using the floor drain as a receptacle for an indirectly connected drinking fountain or other equally effective means

So by code, your humidifier would work. Inspectors over rule the code though and have failed us more than once for using condensate drains as trap primers. But if there's no inspection, give'er

 

[mikeyb7691]

Haha thanks Matt! Honestly I just want to fix the drain so no sewer gas can come into the house anymore. Code aside, is a 4” drain really necessary in the furnace room? I have one in the laundry room.