Sewer cleanout cap size question.

[sparkeyjames]

Since google only turns up one empty clue on this I thought I'd ask here in case someone knows the answer.

I have roots in my sewer line. Not a problem. Ream them out. The problem is the cleanout cap opening measures 2.75 inches. I had to cut out the old brass cap due to age (man was it stuck). This seems to be a non standard size. I have been lead to believe that a 2.5 inch brass cap is what fits this hole. $%^&* ancient plumbing in this house is driving me nuts. Anyone have a clue you can give me?

[herb fellows]

Yes, unfortunately I have the exact same deal. I spent YEARS looking for a new brass cap, or ANY cap, to no avail.
What I ended up doing was putting a pvc end cap piece (like an upside down bowl?) over the hole, ran a bead of caulk where the end cap meets the pipe, and duct taped the whole deal around the pipe a few times.
I' m not winning the ingenuity award, and certainly not the pretty award, but it works.

[woodturner]

Anyone have a clue you can give me?

In addition to the odd size issue, the problem I found is that the threads on the cast iron pipe were so worn and corroded that the correct cap would not thread in.

I found a rubber "plug" at a plumbing supply store. They are available in various sizes and consist of a rubber disk between two metal plates with a bolt in the middle. The bolt is tighted to draw the plates together, which expands the diameter of the rubber disk, causing it to seal.

Remember that sewer lines have essentially no pressure, so you just need to keep the sewer gas contained.

[sparkeyjames]

Threads on the cast iron pipe were so worn and corroded that the correct cap would not thread in.

I found a rubber "plug" at a plumbing supply store.

The threads on this one are in perfect shape. I have considered the rubber plug but what size will fit? I might have a place in town that can custom turn the part but what I'm not sure is can they cut the thread on the odd size part. (standard plumbing thread as far as I can tell)

Jim

[eezlock]

sewer cleanout cap size

The standard waste disposal line for residential lines to the street sewer line is 4".

[sparkeyjames]

The standard waste disposal line for residential lines to the street sewer line is 4".

When did "standard" mean anything back in the 30's or 40's when things like this odd size cap of mine was put in. Remember oakum and lead were used up until the 50's and 60's and probably even the 70's as a standard method with cast pipes. I have seen videos on Youtube about installing that stuff.

[woodturner]

When did "standard" mean anything back in the 30's or 40's

It's not even a "standard" now. Typical residential sewer lines in new construction range from 2.5" to 6". Similar to electric service, the minimum size is determined by the number of fixtures that will feed into it.

[crokett]

Is the 2.75" ID or OD? If it is ID, a 3" cap that Woodturner mentions is sized to fit inside a 3" piece of PVC, and I know the ID is smaller than 2.75". The rubber may expand enough to seal the pipe. How big is the ID? If it is close to 3" a 3" rubber fernco fitting will probably work, then you put on a 3" PVC cleanout and cap.

[sparkeyjames]

Woot! My father found a plumbing place that carries a plastic part that fits that hole. 2.75 inches measured at the outside of the threads. It has a 2 inch screw in cap on top of it. A lot of the houses in the area where my father found this were built back in the 30's and 40's so the plumbing supply place stocks it. Apparently this is a common problem in that area. I cleared the roots and now everything is good.

Jim