Cleaning out a drum trap

Our old house has a drum trap on the tub and it's flowing extremely slowly. I've snaked into the trap, but can't get it clear. I've also tried the enzymatic drain liquids, but they haven't help either.

The next step seems to be to get in the drum and clear it out by hand.

I have access to the top of the drum. The cap seems to be bronze (?). A 3/4-inch square head sticks up from the top of the cap, and I'm trying to figure out how to turn it -- there isn't quite the swing for a crescent wrench down in the hole where the trap is. Is there a tool for this? Any other ideas?

thanks, Pat Singleton

Replace the drum trap with a p-trap? if you can get the old one apart without breaking something, it might be a pain to get it back together without it leaking. A p-trap can be snaked; a drum trap can't. Hair is more likely to go down the drain if a p-trap is used...it likes to accumulate in a drum trap.

Sawzalls work great for cleaning drum traps!

Try using a hammer and chisel to get the drum trap cover to start turning to get it off. Worst case, you have to cut the drum trap cover off. You can always buy a new brass cover, a lead fits-all cover or even a rubber expandable one if the threads are bad. Once the cover is off, you can try cleaning the drum trap out and running your snake thru there.

This is why many people just replace the drum trap entire and install a p trap in its place, but thats not a minor job for an amateur either.

I'll try the hammer and chisel on the cap. Getting the cap off, cleaning out the hair and putting a cap back on is at my skill level. Replacing the trap is way beyond me, and would involve opening up much more of the floor.

thanks again.

Make sure you clean out the drum trap itself too. You need to determine if the clog is before or after the drum trap and rod out the input or output of the drum trap. what are you using to rod it out?

Drum trap covers almost always have to be cut off, which is why my dad said they made them thin. Your problem will be if you have a fine thread version because they no longer make replacement covers for them. Otherwise any hardware store has standard coarse thread replacement. You do not have to clean it out by hand, because the problem is not in the drum trap it is in the outlet pipe and you need your snake there, assuming you have one that will do the job.

I got the cap off. I have a hand-crank snake that I've used for other drains, and I got small clumps of stuff out.

Picasso must have built the drain -- I put nearly 4 feet of the snake in, going from the trap toward the stack, and it feels as though it's all turns. The trap is about a foot from the toilet, it seems like the run from the trap to the main drain (is that called the stack?) ought to be a couple feet at most.

I also did the run from the tub to the trap, and there's no clog in that section.

I got the cap back on, and it's not leaking, but the drain is still slow. Now that I've done it once, I guess I can do it again, and work the snake some more, and see if I just didn't go far enough.

you cant just assume that 4 feet is enough just cause
you think or it looks like it is ....


if it looks like 4 feet was enough, then at least go 8 feet

you want to hear that cable banging around in the stack....

you are very lucky that you were able to get that
plug back on without a leak.....

glad to hear you got the cover off. sometimes they can be a pain. you manage to get it off with a hammer and chisel? absolutely... put more than 4 feet of cable thru the drum trap.

You could always run the water in the tub while cabling the line. This might help push thru anything you are trying to unclog and depending on how slow the drain is, it may be a good gauge to see if you got the clog by seeing the water actually go down nicely while you are rodding it out. I shut up now and let the real pros give you their professional input.... :)

I can't run water while snaking -- the outlet for the drum curves up.

I'm going to snake some more. It's clear I'm on the right track.

What do you mean by "the outlet curves up"? Is the trap inverted? If not the outlet should go level out of the trap.

The outlet that is a cast part of the trap curves up 90 degrees, and then, just above the level of the cap, curves out again. Those curves are part of the trap casting. The outlet is high enough that if I ran water with the cap off, even with the drain completely clear, it would overflow rather than run to the drain.

Could it be that the thing is upside down, and was designed to have the cap on the bottom? This bathroom is on the second floor, so the cap wouldn't have been accessible that way, except by tearing a hole in the ceiling downstairs. So even if it is upside down, I'm glad the cap faces up.

The house is about 100 years old, and this isn't original plumbing. There is a distinct DIY feel to the modern aspects of the house.

I have seen drum traps with the covers on both top and bottom.The standard is on the top.Good job getting the cover off!You have 2 places to run your snake.The outlet towards the main and back to the tub.Make sure you put a 45 degree bend on the end of your snake so you restore some diameter to the line that your doing.

I came across a neat little idea for cleaning out a drum trap that has worked out very well for me. I have a drum trap submerged in the concrete floor of my basement with only the lead top/cap exposed, so the trap cannot be easily replaced without costly concrete work to the floor. This drum trap is the style where the cap covers the entire 4" diameter of the top of the trap and has a 1" square nut in the center. This trap has been there since 1949 and the cap was sufficiently stuck to where it could not be removed without damaging the trap. I took a 2" hole saw and drilled a 2" hole through the cap, centered over/around the 1" nut. It took a little while, but ended up with a clean 2" hole, big enough to get the shop vac and snake through. When I was done, I used a 2", wing nut/compression style, clean-out cap to plug the hole. It is easily removed and resecured for clean outs as needed. Hope this is of value to someone out there as it was to me!