We have a 16 year old Kenmore washer and the manual says you need to have the top of the standpipe a minimum of 39 inches high. Our new er house has the piping/drain set at 30 inches. What is the best solution? Do the newer washers require less height?

You may be able to glue a shot piece to extend.

It's not really how high the standpipe's above the floor but how high it's above the trap that counts. We run our standpipes 36" off the trap. If your's is too short you can simply add a coupling and a short piece to bring it up to standards. Good luck, Tom