Indoor mold

I have a rambler house in Seattle, WA. Every 1-2 years there have been spots of mold appearing on 2 bedrooms (lower half bottom) walls facing the west (where the sun goes down) after I cleaned & wiped the walls with a bleach. I already replaced the roof and windows with double insulated glass windows (vis-a-vis single pane glass where I can see moisture dripping during winter time). Still have this problem now. It is only these 2 rooms inside the house that have a problem and not other rooms. I monitored the humidity and are in the range of 65-80. It seems always humid in these bedrooms. What may be the problem? And, how to get rid of these molds in a long term?

Thank you, TONY

You need to be inspected for water intrusion to locate the source of the moisture. A thermal imaging scan would probably be the best way to confirm the location of the source.

Bleach does not touch mould it just removes the colour.
You need to find Why the humidity ,
We need more info what direction are the rooms facing .
Is there any air movement in these rooms .
Have you tried a dehumidifier to see if it lowers the rooms .
Is there a exhaust fan in the Bathroom and is it used .
Is there an kitchen exhaust and is it used when cooking .
Do you dry clothes in the home or these rooms do you have a dryer and does it exhaust out side .
Are these rooms open all the time or is the doors closed .
These are just a few of the questions that need to be answered.

Thank you Mr. Frotte for your reply.
Where can buy/rent a Thermal imaging scan? Would a non-contact thermometer with laser targeting work?
If the Termail imaging scan is expensive to buy/rent, would you recommend someone in Seattle who can do it for me?


EMSL rents and sells them.


You can’t just rent the equipment. You need to be trained in how to use it. Google search your area for someone trained and certified.

Mr. Roy Cooke:

Thank you so much for your time to respond through the website and also your recommendation when I called you directly on how to eliminate the “Indoor Mold” issue.

It is so kind of you!

Take care,
Bellemoore (Seattle, WA)

Good info thanks Jeffery …

I talked to him for about 20 minutes and his moisture reading in the home are usually in the high sixties to low 70 %.
I told him I like to see it about 50%
My feeling with what was said most of this is caused by Crawl space vents .
I recommended a automatic Dehumidifier with hose to a floor drain .
Close C.S. vents use Bath and Kitchen fans more .
He did not have a gas stove ,Most of his moulds are in the west rooms .
Most of his wind is from the west so these rooms could be cooler .
He had some knowledge and was a very good listener .
I expect to hear from him again be interesting to see what the out come is,