[Montybell]

I have an 8 inch clean out for a commercial property I own. It's extremely difficult to find in stores and people back over it at the street level regularly. Any body know why my business is equipped with an 8 instead of a six?

[Chris]

Originally Posted by Montybell

I have an 8 inch clean out for a commercial property I own. It's extremely difficult to find in stores and people back over it at the street level regularly. Any body know why my business is equipped with an 8 instead of a six?

It is very common to have an 8" sewer line in a commercial property, usually whatever the civil engineer that drew the plans says goes whether it's needed or not. i am still a little confused on what you are asking? Is there a problem that I may be able to help you with?

[Montybell]

I was just wondering if there was a method to the madness. Eight inches are harder to find and cost more so I was wondering if there is a practical application for this or if was just the plumbers choice me.

[Chris]

Originally Posted by Montybell

I was just wondering if there was a method to the madness. Eight inches are harder to find and cost more so I was wondering if there is a practical application for this or if was just the plumbers choice me.

No real method, alot of time civils will either not really know and go overkill or there will be some math problem involved that makes no sense to anyone. I don't know where you live but here is two companies that you can get parts from at a decent price and they are nationwide. Just google one of them and see how close you are, they stock all 8" parts. I personally like HD better and that is who I buy from.

HD Supply Waterworks

Ferguson Waterworks

['Cause]

The size is strickly based on what are called 'fixture units' (FU's) and defined by your Building department (BD) standard. IE.. one toilet may be worth 4 FU's, a shower 2 FU's, a lavatory 1.5 FU's... and so on... then there is a table of values in the 'Code' used defining the size required. This info is compiled by the Plumbing design engineer and given to the Civil Engineer.

[Nailer341]

You have an 8" Clean out because you have an 8" sewer line.
I don't know how big your building is, or what water and sewer services you are utilizing, but I can tell you that you should be very grateful to have a large sewer line. All too often we run into issues where the sewer is too small for the proposed fixture units, and it becomes a big pain in the ass to fix and a big unwelcome expense for the building owner to repair.

Don't worry... Be happy. Seek out the parts for your 8" claen out with a smile on your face

[Chris]

Originally Posted by Nailer341

You have an 8" Clean out because you have an 8" sewer line.
I don't know how big your building is, or what water and sewer services you are utilizing, but I can tell you that you should be very grateful to have a large sewer line. All too often we run into issues where the sewer is too small for the proposed fixture units, and it becomes a big pain in the ass to fix and a big unwelcome expense for the building owner to repair.

Don't worry... Be happy. Seek out the parts for your 8" claen out with a smile on your face

I agree with that. Alot of times when I am putting a main in the owner will try and use a 4 or 6" to save a buck. The bigger the better.

[hcj]

The codes specify that the line has to have a "full size cleanout" up to 4" and a 4" cleanout MINIMUM for larger pipes. Therefore we usually only install 4" ones and it is not a question of cost, it is one of practicality. Most lines can be cleaned through a 4" cleanout.

[Chris]

Originally Posted by hcj

The codes specify that the line has to have a "full size cleanout" up to 4" and a 4" cleanout MINIMUM for larger pipes. Therefore we usually only install 4" ones and it is not a question of cost, it is one of practicality. Most lines can be cleaned through a 4" cleanout.

We have to install full size cleanout in my area regardless of minimum unless stated on the plans. For instance if I am installing a 10 sewer line and put a 4" riser on it for a cleanout and 2 years down the road there is a problem I am responsible because I did not install it per plan and I will have to dig it up and fix it. I have run into this problem before.

[Nailer341]

Originally Posted by hcj

The codes specify that the line has to have a "full size cleanout" up to 4" and a 4" cleanout MINIMUM for larger pipes. Therefore we usually only install 4" ones and it is not a question of cost, it is one of practicality. Most lines can be cleaned through a 4" cleanout.

You are right: (well, almost. code specs 3.5" min.)

707.11 Cleanout fittings shall be not less in size than
those given in Table 7-6.

I do often see in some of the more industrial uses that the cleanout size does match the pipe size even in the larger dia. pipes. I guess it is at the discretion of the engineer, and not dictated by the CPC.

Good call, and thanks for the correction.

What state are you from?