Does drain cleaner settle in P-trap before it works down through the line?

Using some drain cleaner in my kitchen sink to clear a clog. How do I make sure the drainer clears the P-trap to go down thru the line? Direction say to use 16 ozs. of 32 ozs bottle and leave for 10 minutes. Then flush the drain with hot water after the 10 minutes. It seems most of the drain cleaner will set in the P-trap for that time and not continue on down through the pipe? When does the cleaner take effect thru the line? Thanks!

How does drain cleaner clear P-Trap before flushing drain? Does the majority stay in P-Trap?
Thanks! See pic. of P-trap.

 

16oz of liquid is about 29 cubic inches. Your trap holds no more than about 10 cubic inches. So only about 1/3 of that 16oz is in the trap, the rest went down the drain.

Drain cleaners are seldom the best way to clean a drain. You typically want to remove the trap completely and snake down the drain pipe. And you dump out anything caught in the trap and clean it. That's why most traps have slip joint fittings... for easy maintenence.

 

Thank you. I've already snaked the drain from the far fittings to the wall. I came back with nothing or very little. I called the plumber and he said he may have to hydro jet it at the cost of $600 to do the job. I am trying everything before I bring him in. I have an open and tall crawl space(I can walk around) across the house so will go down and see if there are any coupler fittings through the line. I'm positive there is a 90 degree angle or a at least a 45 angle down there. I will check it out, maybe I can snake it from there. If I have to pick the house up and move it 10 foot west, I will! ha ha No, I'm serious.....

 

* Open and tall crawl space..... I can walk around.

 

Look for any cleanout plugs down the line.

 

Putting in a coupling mid-way on a long drain is not uncommon. I had to do this since about every 2 years or so I get a buildup and a clog and clearing it is breeze since I installed the union coupling.

 

Most likely your sink drain will have a horizontal run in the crawl space all the way to where it empties into the house drain. At the inlet side of the horizontal drain there should be a clean out. A code requirement in my area.

If you remove the clean out to snake the drain, do it carefully with a bucket, and a raincoat.