I have this white chalky residue on the walls in one of our bedrooms. It's on every single wall, from top to bottom except behind posters and pictures. When I wipe it with my hand it feels grubby but no smell. The bedroom is the only room in the house that has this problem and is located on the top floor of the house. It is not next to a bathroom or near any plumbing. There is no masonry used in the walls in this room. The room was painted about 4 or 5 years ago. When I clean it, it comes back within a week or so. There are no dark mould spots anywhere in the room. I have no idea what this is but I want to get rid of it. Any ideas on what it is and how I can remove it for good?

 

Are you keeping that room fully heated or closing the door/heat off?

It sounds like the minerals left over after moisture evaporates. If the room is cooler than the rest of the house, the warm air is pushed up to the top floors along with the moisture it has accumulated from below.

Can you access the attic?

Bud

 

Also how old is the house? drywall or plaster?

 

The house is 25 or 26 years old. The bedroom is occupied by my brother in law who complains that there is no air circulation in there. He sleeps with the window open and a fan going. I believe that because he has a computer in there that it is generating extra heat. There is an entrance to the attic in the closet of that room. I will be investigating it today and let you know what I find. That you for the help, so far.

 

Do you know what brand/line of paint was used? Some of the cheaper flat latex paints can be degrade by moisture and night air is usually fairly moist.

 

Check that attic hatch to be sure it is well sealed and insulated. An air leak into the attic will mean more house air flowing into that room with more moisture. Besides the cost, moisture is bad in the attic. The computer would be generating very little heat and would be contributing zero moisture.

What type of heating do you have, forced hot air or baseboard hot water? Do you run a humidifier and do you see any moisture on any of the windows in the house?

Bud