My washer keeps backing up and flooding the laundry room. How do I prevent this?

You probably have washer lint or something else blocking the drain pipe. I have pulled loads of it out of washer drains. Have someone auger the washer drain line and the pipe it connects to. You'll be surprised what will be found.

Did the backup just start? What size washer standpipe. Do you have? With today's more powerful washer's a older inch and a half installation won't carry the volume. If this is the case I have a solution for you. Post back with more details. Back to you, Tom