We started having problems with sewer odor in our conjoined bathroom/laundry room after using the washing machine. The plumber who came out to help didn't see any problems, but recommended my husband start pulling insulation off the drain pipes to look for a crack. We live in AK and it is 20 below outside... pulling insulation off seems risky. Any suggestions to help localize our problem or should we simply look for a better plumber? Again, the odor is only apparent after using the washing machine.

Thanks,
Cara