Expert: Jamie Yocono - 2/11/2009

Question
Hi Jamie,

We're in a 16 yo post & beam in the NH woods.  Our bathroom shower has an
exposed oiled (okeen) white pine beam that now has some black spots.  A
patch of the  exposed ceiling is sikkens stained spruce - it has some dark
areas indicating mold.

What is the best way to clean the beam & ceiling and remove the darkened
areas.  Is a bleach solution an option?  Please send any preventitive
suggestions - would a poly in this area help in the future?
Many thanks,

Denny

Answer
Hi Denny,

You're dead-on correct to think that bleach is an option. But I have a two-part suggestion. Regular household bleach will kill the mold, I've diluted it 50/50 with water and sprayed it on wood to eliminate mold. I usually let it sit on the wood for a while, then scrub the surface lightly with a brush. If the area is small, a toothbrush. If it's bigger, a soft bristled brush like a dishwashing brush works fine. Wipe and rinse with water, and let it dry.

Afterward, if the wood is water-stained, you might try oxalic acid, which is common wood bleach. I do not know if this stuff will kill mold, so that's why I'm suggesting regular bleach first, then this wood bleach to eliminate the staining. This stuff really works well, and you can buy it at any good paint supply store. I bought my last box at Sherwin-Williams. Mix it according to the directions, apply it, and let it soak in, Then rinse it off. You will be amazed at how it can eliminate those black water marks, although if the stain is deep into an open pored wood, some black spots may remain the pores.

You can read about wood bleach here: http://www.realmilkpaint.com/oxalic-acid-bleach.html

Another thing to think about - bleach doesn't totally eliminate mold. Sure, it will kill it, but I think unless you eliminate the dampness in the air, it will come back. My folks owned an old farm house that had mold in it, and we rented an ozone generator from a rental company, to "clean" the home of mold. Look, I'm not nearly smart enough to understand how this device works, but you can read about it here: http://www.mold-kill.com/

We plugged in that rented machine, let it run for a few days, and afterward, the mold never returned. You can't live in the home while this device is running, it's sort of like "fumigating" the house. But as long as you do this, and you eliminate the source of moisture, you will kill the mold and it won't return. In my folk's case, they had a burst pipe that flooded the house that they didn't discover for a few days. So they fixed the pipe, cleaned up the water and mold, then ran this generator and the mold never came back. I think that the rental was like $15 a day, or $60 for a week... a bargain, considering what it did.

Anyway, just thought that info might help you. Hope this answer is what you were looking for, good luck, and write back if you need more help.

Jamie Yocono
Wood It Is! Custom Cabinetry
Las Vegas, NV
www.wooditis.com