Hi, all.

On one side of my son's 2nd floor bedroom, a musty smell will become noticeable every time we close his door more than 1/2 way for more than 10-15 minutes. This has been happening since we moved in 2 months ago. It does not coincide to rain and comes back after you air out the room.

His room is 2/3 over the garage and 1/3 over a powder room. It is under a dry attic. It is next to the full bath, which is not used except with a baby tub, so no water hits the fixtures or tiles - only the tub is used.

There is no visible sign of leakage anywhere.

Humidity in our area and in the house is about 60-70+ %.

The moisture related possibilities in his room that I see are 1) baseboard heat, 2)drain vent pipe, 3) garage humidity, 4) possible water pipes servicing the shared bath, and 5) a portico (roof) over the front door which attaches to the exterior siding outside his room.

Given that it is a perpetual smell, I was thinking that it was water / vent pipe related. The garage climate isn't that different than the house, but I will be installing a dehumidifier tonight anyway.

It's a difficult situation. Can anyone suggest where to start?

Thanks,
HomeGuy

Hey Guy,

"His room is 2/3 over the garage and 1/3 over a powder room. It is under a dry attic. It is next to the full bath, which is not used except with a baby tub, so no water hits the fixtures or tiles - only the tub is used.

The moisture related possibilities in his room that I see are 1) baseboard heat, 2)drain vent pipe, 3) garage humidity, 4) possible water pipes servicing the shared bath, and 5) a portico (roof) over the front door which attaches to the exterior siding outside his room."

You missed one, (6) The water seal in the traps in the bathroom has evaporated due to lack of use and is now allowing sewer gas to escape.
Either fill the traps with water and keep then filled or if they aren't going to be used fill the traps with motor oil and forget them. Let me know. Tom

Thanks for pointing that out. We actually use the tub and sink every other day when my son takes a bath, so the traps should still be full. However, I know what you mean. We had some time pass between when we bought the house and when we occupied. During that period, I had to keeps the traps filled.

My gameplan is:

1) Move my son into the other bedroom temporarily.
2) Cut open some areas of wall in the corner and inspect.
3) Have plumber look into what's there (& cut more if necessary)
4) Replace baseboard element in that section.
5) Bring in roofer to reshingle and reflash portico. Some siding will be taken off during the install of new flashing.

I don't know what more to do. I hope our suspicions about that corner of the room are correct. I also hope that I do not start opening ceilings below.

Anymore suggestions? I could sure use them.

Thanks,
HomeGuy

I don't see any more that I can suggest. I assume you've opened up the access panal behind the tub and checked for moisture there. Let me know what you find. Good luck, Tom

Hi, speedball.

There is no access panel to the tub as far as I can tell. The plumbing of the tub in the shared bath also services the master bath shower on the other side of that wet wall. :( Ugh.

HomeGuy

Opened up some areas of wall in the bedrrom and stuck my hand in. The stud at the base of the wall about 3 feet from the common wall to the bathroom is damp. The insulation in the wall is dry. This spot is also close to the portico outside.

Still not conclusive. I will open one more hole on the wall opposite the back of the bathtub. Help...