We recently purchased a home with a finished basement. When we had the home inspected, we noticed a methane smell coming from the laundry room. As part of the inspection report, we asked that the sellers determine the cause of the smell and take care of it. When we did the walk through, we noticed that the smell was still there. We ran the water in the utility sink and the washing machine. However, the smell did not dissipate. We decided to purchase the home with the proviso that money be escrowed to deal with this problem. Our plumber came to the house and all simply attempts to solve this problem, have failed:we checked the line that connects to the sewer and the cap seems to be tight; we plugged the utility sink but the smell remained; and, finally, we covered the area in the wall where the water shut-off is located andnothing happened. We are starting to think that we will have to tear apart the laundry room wall to see of the contractor installed a p-trap for the washer. Before we take this drastic step, any advice?

"We are starting to think that we will have to tear apart the laundry room wall to see of the contractor installed a p-trap for the washer. Before we take this drastic step, any advice?"

To check for a washer trap run a stick down the washer standpipe and if it comes back with a few inches of water on the end you have a trap down there. A more likely spot to check is the floor drain. If it's not going to be used pour a pint of motor oil down the floor drain to fill the trap so it doesn't evaporate away. Good luck, Tom