Keep the soap going while flushing. So make sure house drains get a shot of soap.

Good point! The vapors will be in the piping back to the p-traps on the other drains also.
Perhaps you could drop a match down one of the plumbing vents and clear it out...![]()
DO NOT ADD DISHWASHING DETERGENT THINKING THIS WILL DO ANYTHING PERMANENT!!! Adding Dawn, while seemingly effective, is a bad idea. Even though it looks like is is breaking up the gasoline, those actions are temporary. The gasoline will reform on the surface later. So even though it may not smell fumy after stirring some Dawn into it, walk away and come back in a few hours and you have fumes because of what I just described.
Erring on the side of caution, I'd call the Fire Department. Enough fumes in a small area can cause an explosion, and it does not take much volume to accomplish that.
Full on disclaimer here. I have absolutely no idea what I am talking about. There is no one alive that can claim he or she has ever followed my advice (coincidence?)
If you unwisely chose to ignore the above advice... Ventilation is the key. Don't let the air sit around. Open that garage door and have a box fan, sufficiently far away blowing across the trap and out the open door. Don't flush water into the trap, this will move your problem (gas/fumes) elsewhere outside the trap. Any sinks/tubs/etc. you haven't used in a while - fill em with water. You don't want dry traps elsewhere in the house. Get out that shop vac and **** the trap dry. If it makes you feel better add some Dawn to the trap and the shop vac canister (set it up for wet use and empty it). After turning off the vac, remove the power source, take the lid off (no fumes in confined spaces), move it outside and dispose of properly (whatever that may be). Refill the trap. Use water this time.

Blow it out with a shopvac set as a blower... that should blow it out of the trap without the fumes getting to the shopvac (which will result in a big boom).
Don't even kid about the match. I worked worked a guy that had yellow jackets around his block foundation. He poured gas down the hole & later put a match to it,blew in the wall in the laundry room in the basement.
It's silly that you're spazzing about the severity of this, yet you tell him to start a vaccuum motor around gasoline fumes.
Air it out, dillute the fuel. Don't listen to Steve. All will be fine.
I told him not to listen to me! The issue with fumes is in the trap itself and the pipes, not in the garage. It was also written when he said nearly a gallon and a very strong odor vs. half a gallon max.
The correct answer answer is to let the pros handle it as opposed to random folk on the internet. If you are dealing with your house and your family, you can take whatever risks you are comfortable with. Me, I'd do exactly what I suggested.

All of you are over reacting. Go to bed! Tomorrow, everything will be fine.

I told him not to listen to me!........
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.............. Me, I'd do exactly what I suggested.

Nice first post.
It's to small to be a reportable incident. Flush it with copious amounts of water.
I'd suggest you close the gas can or put a lid on it. The next it gets knocked over, there might be an ignition source nearby.
No kidding. I mean seriously. The fireman said what needs to be done.I am quite blown away (pun intended) at the massive spazzing out and over reaction throughout this thread!
that is about 5 - 8 sticks of dynamite you spilled. Ask any boater about the dangers of spilt gas in a confined aread.



Will those boaters know what 'spilt' means? LOL Just kidding, I know you meant either 'spilled' or 'spit'. Neither one's ideal to do with gas...
""Spilt...verb...a simple past tense and past participle of spill.""

Don't even kid about the match. I worked worked a guy that had yellow jackets around his block foundation. He poured gas down the hole & later put a match to it,blew in the wall in the laundry room in the basement.
To the OP
FWIW Nuts is a firefighter ( in case you missed his avatar) and likely has both the expertise and experience you want.
His is the nearest to expertise you will find in this thread.
