Peeling paint occurs when wood contacts concrete
Q: I notice that the paint peels off much too often at the bottom of the side jambs on my front door. I repaint these areas, but a few months later, the paint near the concrete starts to peel. I hate painting, so can you tell me what is happening and how I can fix it?
A: Painting is no fun. The only thing worse than painting is having to paint again and again. Unfortunately, your peeling problem is fairly common.
If you look around your house, you will probably notice the same dilemma at other locations where wood meets concrete, such as the wood frame around the garage. This happens because concrete loves to drink up water and, as it does, it slowly releases moisture. So, any wood that is in contact with the concrete gets a little damp.
The dampness wicks up the wood and breaks the bond that holds the paint to the wood. So, what can you do about it?
You will need to scrape and sand down the area so that the bare wood is exposed up to 1½ feet above the concrete. You can do this with paint scrapers and 80-grit sandpaper. Scrape the majority of the peeling paint away, and then get rid of stragglers with the sandpaper. The 80-grit paper will leave a scratchy surface, which is ideal for a good surface bond.
Next, you want to create a gap between the wood door jamb and the concrete. You can use a thin piece of wood (¼-inch thick), lay it down on the concrete, and then place a hand saw on top of it. You can easily cut the jamb and molding with a few passes. After the gap is cut, either clean out the debris with a shop vacuum or blow it out with compressed air.
Protect the surrounding area by covering it with blue painter’s tape. Spread the tape on areas you don’t want to be painted, including the concrete under the gap you just cut. Use several layers so you don’t stain the concrete.
Now you want to spread a little water-repelling love on the bare wood. Use a “paintable” repellent (you can buy it at a home center or paint store) and brush it on the bare wood. Wipe off any repellent that doesn’t absorb into the wood. Don’t forget under the jamb that you just cut, as you need to get the repellent under there to seal the end of it.
You can slather some of the repellent on a thin piece of indoor/outdoor carpet and run the piece into the gap and rub it on the underside of the jamb. You can use anything thin that will both hold the paint and slide under the jamb, such as a putty knife.
The next step is to apply a primer over the repellent. The label on the repellent’s bottle will tell you how long to wait before brushing on the primer. Brush it on in the same manner that you applied the water repellent.
Finally, apply two coats of latex paint to the jamb, and also to the underside of the jamb. This is a pretty straightforward process that should get you back into painting only every couple of years instead of every couple of months.
Mike Klimek is a licensed contractor and owner of Las Vegas Handyman. Questions may be sent by email to handymanoflasvegas@msn.com. Or, mail to 4710 W. Dewey Drive, No. 100, Las Vegas, NV 89118. His web address is www.handymanoflasvegas.com.