My experience with sewer backwater valves

[kiwi_outdoors]

FYI:
when we bought our house we did not realize what the stained nail heads in the master bedroom meant. They were in fact evidence of a prior intrusion of blackwater diluted by rainwater via the Master Bath shower pan. This occurs because the city's sewer line surcharges during heavy rains.

We figured this out after it happened to us (no turds, thank goodness). There was a cast iron backwater valve in the crawl space under the house, but it leaked a bit. Not good.

Next step was to find the (buried !! ) cleanout where the clay sewer pipe joined the 3" under-house C.I. sewer piping. The cleanout tee was just outside the house foundation.

As a quick fix I completed the cleanout to above grade and left it as a vent-overflow, so at least the diluted sewage would no longer enter the house.

There followed a period of research into backwater valves.

Next up was the final fix, rebuild the vent closer to the house and add a proper PVC type of backwater valve between the cleanout-vent and the clay pipe (city side).

This gives us a foolproof automatic method. The backwater valve remains closed except when we flush the toilet or tuns the shower etc.

When we get a major rain event, the small amount of valve leakage overflows from the vent into its surroundings - a "fern garden" - this is only liquid, no turds, no TeePee.

Points of note:

We have installed a "Cleancheck Extendable Backwater Valve" by Rectorseal
The guts of the valve is easily removable from the surface.
The flapper needs to be properly cleaned periodically
The fixed mating face (underground) needs to be cleaned with a water jet, including the upstream section of pipe. I use a hose end fitting (and some extra PVC) used for RV blackwater tanks.
Buy lots of spare flappers while they are still available - the rats chew on our flappers. We have replaced two flappers so far. (rats really do get around in the sewer pipes)
My open vent allows air circulation for local-to-house sewer gas to vent outside the house.
I usually remove the "guts" in our long dry California summer, to reduce the rat damage to the valve flapper.
TIP: When you have a surcharge event - do NOT unscrew the cap of your valve's standpipe to "take a peek" - you will be greeted by TP and turds.

Any comments?

P.S. Our neighbor's recently installed exterior sewer cleanout was not capped tightly, and it was leaking liquid during the last big rain event.

 

[Geofd]

Yes a back water valve Is meant to prevent sewerage from backing up into the lowest level of your house , if it was not there and there are fixtures in the lowest level they will overflow until the city or property drain issues are solved.
An outside cleanouts is great to have, if there is a drain issue in the yard before the street that's your access

 

[Twowaxhack]

Backwater valves are illegal here. We have very few basements and the ones that are here are below the sewer main so they require pumps .

We pipe a sewer overflow outside, no backwater valve.

 

[kiwi_outdoors]

I have no expectation that the city will upsize the clay pipe in the street - which is the true solution to the pipe being too small for its flow.

Oakland needs its $$ for the huge homeless problems, and potholes.

 

[Twowaxhack]

Let’s go Gavin

 

[kiwi_outdoors]

Or house is single storey, and above grade. The surcharging pressure in the sewer pushes sewer liquid up above the shower pan, and out it goes. Before the backwater valve we installed, that is.

 

[kiwi_outdoors]

BTW - on the subject of cleanouts - I was not pleased with "trade practice" when the house was built in 1964 here in Calif. Both crawl space cast iron cleanouts were under the house (hard to access) and one of them was unusable by a "roto-rooter" guy due to its location. I extended both of them thru the foundation well so that they are fully accessible from the paved area outside the building.

 

[kiwi_outdoors]

BTW - on the subject of professional practice - when our 1964 house was built the cast iron pipe in the crawl space was laid across a concrete foundation's "grade beam" resulting in a hump in the cast iron sewer pipe - a hump in the pipe's slope that eventually led to repeated blockage in 2020. I had to drill multiple holes thru the grade beam and break out a slot to lay a new section of pipe, and ultimately get all of the pipe leg set to a unified grade. No more backups!

All this work was done in a literal crawl space.

 

[Twowaxhack]

BTW - on the subject of professional practice - when our 1964 house was built the cast iron pipe in the crawl space was laid across a concrete foundation's "grade beam" resulting in a hump in the cast iron sewer pipe - a hump in the pipe's slope that eventually led to repeated blockage in 2020. I had to drill multiple holes thru the grade beam and break out a slot to lay a new section of pipe, and ultimately get all of the pipe leg set to a unified grade. No more backups!

All this work was done in a literal crawl space.

I’ve dug 5’x5’deep holes under a house that was 30” off the ground. The dirt was piled onto plywood and a tow strap is attached and you can use various equipment to pull the pile of dirt out from a winch to a truck bumper.

Replacing sewer pipe.

The first one I did the movie Nightmare on Elm street had just come out. I named my job Nightmare on Ann St, that’s the street we were working on.

I’ve had the entire floor cut out of homes with not enough crawlspace clearance.

Once I was going to replace a tub drain. It was on a concrete slab. I had to break open a small section of slab to do this work.
I use a little jackhammer to accomplish this. When I broke through the slab it all caved in easily. I found a cavern that was 8’ deep and 15’ long after we pumped all the water out.

We finished breaking the bathroom out, replaced a big section of drain. Packed the entire hole with red clay we brought in with wheelbarrows.

I was literally walking around under the slab, used an 8’ ladder to get into the hole.

 

[Twowaxhack]

Here’s the one that we had the floor cut out of. It wasn’t framed properly anyway.

 

[kiwi_outdoors]

1st Update on the Backwater Valve Saga. The City made a "fix" on their sewer system - by adding an extra pipe bypasss to allow some flow to get by the 90 degree bend. This involved the new pipe, two new manholes, and rebuilding an existing manhole. This "fix" was recently tested and mostly failed. It reduced the surchage pressure, but the blackwater would still flow into the house if we did not have the backwater valve and relief vent.

 

[kiwi_outdoors]

2nd Update on the Backwater Valve Saga: I went to replace a rat-chwed flapper with one of my 6 spares - only to find that Rectorseal had changed the design of their Clean Check valve in order to make replacing the flapper easier. The fitting at the bottom of my inner riser is no longer useable. So I sent them a polite email describing my sad story, and they graciously sent me a "rebuild kit" for free. So it only cost me $58 for a new length of 4"" PVC (5 ft minimum) from the local plumbing supply house to make an all-new inner riser and to keep the rats happy with something to chew on.

 

[JeffreyWisc]

I’ve dug 5’x5’deep holes under a house that was 30” off the ground. The dirt was piled onto plywood and a tow strap is attached and you can use various equipment to pull the pile of dirt out from a winch to a truck bumper.

Replacing sewer pipe.

The first one I did the movie Nightmare on Elm street had just come out. I named my job Nightmare on Ann St, that’s the street we were working on.

I’ve had the entire floor cut out of homes with not enough crawlspace clearance.

Once I was going to replace a tub drain. It was on a concrete slab. I had to break open a small section of slab to do this work.
I use a little jackhammer to accomplish this. When I broke through the slab it all caved in easily. I found a cavern that was 8’ deep and 15’ long after we pumped all the water out.

We finished breaking the bathroom out, replaced a big section of drain. Packed the entire hole with red clay we brought in with wheelbarrows.

I was literally walking around under the slab, used an 8’ ladder to get into the hole.

The last line makes me cringe! Yikes!

 

[Twowaxhack]

The last line makes me cringe! Yikes!

That’s how the cookie crumbles

 

[breplum]

Interesting news about the Clean Check re-design of flapper.