washer drain issue

when my brother in law installed the washer a few years ago, he connected the washer drain through the sink drain. I am very tired of dealing with this problem. i snaked the drain line but water still bubbles up in the sink when the washer drains. the drain line is 1 1/2" . seems to me that the washer ejects water too fast. could someone help me with instructions on how to drain the washer into the main drain line? the main drain line runs under the house which is on a crawl space and i i have plenty of room to get under the house for the work. thanks in advance for any help

rjherald

There is NO way we could possibly make a recommendation without seeing the actual site. And, from your brief description it is very possible that this is NOT something you should consider for a "first time DIY plumbing job".

1½ is too small, which is why you have the back up. It IS permissible and common to just put the washer drain hose into a washtub sink.
The sink just buffers the output of the washer, and does drain eventually without overflowing.
Otherwise, the washer must drain into a standpipe of appropriate height. There must be a trap above floor level. Then it could connect down to the main line, but must be vented as well.

We would like to see some photos....it sounds like there may be more than one mistake with the current setup, and redoing it might be an ambitious project.
\