No washing machine standpipe vent?

[Brian Kehlmeier]

I currently have this setup in my two story home's basement. I am pretty sure that the standpipe penetrates the slab then take a 90° turn before terminating into the vertical floor drain pipe. I don't believe there is a trap in the run of the standpipe.

I am moving the laundry room up to the second floor, into a room which is bordered by the attic above the garage and our master bedroom living space. The attic above the garage is not connected to the attic above the rest of the home; it stands alone.

My questions are regarding the current setup and what I need to do with the new standpipe on the second floor:

• Is my assumption of the current standpipe not having a trap correct? Is this type of setup normal? I believe I grew up in a house exactly like this as well.
• If the new standpipe on the second floor is not tied to the main stack (I plan on running the new standpipe to this existing standpipe in the basement and drain the water in the same way it is now), does it need a trap?
• If the new standpipe is not tied to the stack, but rather discharging into a floor drain such as this, does the vent need to terminate outside or does it only serve the purpose of allowing the water to flow? If the later, can I just leave the vent terminated in the attic?
• The trap at the bottom of the floor drain is there to prevent sewer gasses from making it into the house. I know in the winter months, I have to fill this at times to prevent it from drying out, as condensation from the air handler is not being produced. They does this floor drain not require a vent to take the possible sewer gases out of the house?

I have lurked, reading this forum for decades. This is my first post and I hope I didn't fall short of the forum expectations.

 

[Terry]

The washer needs a standpipe with trap and the trap needs venting.

UPC
804.1 All plumbing fixtures or other receptors
receiving the discharge of indirect waste pipes shall be
approved for the use proposed and shall be of such
shape and capacity as to prevent splashing or flooding
and shall be located where they are readily accessible
for inspection and cleaning. No standpipe receptor for
any clothes washer shall extend more than thirty (30)
inches (762 mm), nor less than eighteen (18) inches
(457 mm) above its trap. No trap for any clothes
washer standpipe receptor shall be installed below the
floor, but shall be roughed in not less than six (6)
inches (152 mm) and not more than eighteen (18)
inches (457 mm) above the floor.

Your local code may read differently.

I have never terminated a vent in an attic. I don't see anyone allowing that. Venting goes through the roof, or some will use an AAV (auto air vent)

What you had doesn't look right. Nope!

 

[Sponsor]

 

[Brian Kehlmeier]

So this setup in homes is not compliant with most codes?

So I use a trap in the new standpipe and vent it properly through the roof, do I need to discharge the new drain line into this existing standpipe or tie it into the main stack?

 

[Terry]

You can tie the drain back into a waste stack, not a vent stack.
I'm not even sure the washer in the basement wasn't the unfinished vent for the floor drain.

 

[Brian Kehlmeier]

Wouldn't the vent for the floor drain be AFTER the trap? I can tell the for drain has a trap by the standing water and when it's wet there is no smell.

 

[Terry]

Wouldn't the vent for the floor drain be AFTER the trap? I can tell the for drain has a trap by the standing water and when it's wet there is no smell.

Okay, where is the vent for the standpipe?

 

[Brian Kehlmeier]

The standpipe has no trap, so there is no vent. I'm sure that isn't the reason why, but that's reality. The neighbors house is the same, just like my parents. Odd. Would this be old code? I don't think the floor drain trap has a vent either.

To do this right, I'll tie into the stack, trap the standpipe and add a vent out the roof.

I am so perplexed by the setup in these homes. All built between 65 and 80 in Columbus, Ohio area. All the homes have washers draining into pipes just like this

 

[Terry]

I've never seen washers plumbed that way either. All I can advise though is how it was supposed to have been done, and with upgrades as we go along to newer codes.

 

[Brian Kehlmeier]

Same situation is this thread. I find this fascinating and would love to know how commonplace this is.

https://www.thisoldhouse.com/discussions/topic/appropriate-use-basement-floor-drain

 

[Cool Blue Harley]

I've never seen washers plumbed that way either. All I can advise though is how it was supposed to have been done, and with upgrades as we go along to newer codes.

Homes were plumbed that way everywhere in the 60’s and 70’. And perfectly to code at the time.

The clothes washer standpipe does not need a trap or vent because it discharges indirectly into the floor drain tailpiece, upstream of the trap. It’s clearly visible in your second photo. It’s the same as emptying a dishwasher into a kitchen sink dishwasher tailpiece, before the trap.

This arrangement kept the floor drain trap primed. Usually there was a utility sink which acted as a reservoir for the clothes washer.

The problem with this archaic design is threefold

1) modern clothes washers discharge more rapidly and the indirect pipe can’t keep up
2) some modern detergents produce suds which bubble up from the floor drain, leading the homeowner to believe there is a stoppage
3) the underslab 90 for the vertical to horizontal transition is Durham or simply a galvanized 90, not a sweep fitting. After 50 years, they are clogged beyond snaking.

 

[Brian Kehlmeier]

So now a new question becomes apparent: How do I keep the floor drain trap prime after tying the new standpipe into the stack?