Saturday, December 31, 2011
Exterior Brick Walls and Acrylic Mortars
We would like to paint our home’s exterior brick walls before putting the house on the market. Some bricks are damaged and we are planning to have them repaired. Our problem is that we were told we’d have to wait 28 days for the mortar to dry before painting. I’ve read about an acrylic mortar that can be painted sooner. Is this something we could use?
Painting the brick exterior of your house just before you put up a “For Sale” sign may not be your best move. There are lots of people living happily in painted brick houses, true. But there also are lots of people out there wondering how the heck to get paint off their brick walls.
Unlike wood siding, brick doesn’t usually need paint for protection. It’s really an aesthetic decision, one that potential owners of your house may not appreciate you making for them. They might love the house, but hate the fact that it’s painted. Or hate the color you’ve picked.
Another reason to think twice about painting a brick house is that you are creating, in perpetuity, a maintenance headache for someone else. You’ll be living safely elsewhere but the buyer can look forward to repainting the exterior of the house every three to five years.
For repairs to brick, avoid acrylic mortar. As to repairs, you may be able to find premixed acrylic mortar patch, but it’s probably not a good choice in your situation.
Cathedral Stone Products, a Maryland company that specializes in masonry restoration, recommends against it because this type of mortar is too hard. It may, in fact, lead to more damage in the wall over time. Acrylic mortars also trap moisture inside the wall, another problem.
Instead, the company recommends that mortar used for repointing be softer than the brick. If anything fails, it will be the mortar and not the brick. The type of historic pointing mortar that Cathedral sells is called Jahn, it does not contain acrylic or latex additives, and is completely vapor permeable.
If you must paint, give the mortar a chance to cure. Your mason is giving you good advice in waiting for 28 days before painting new mortar. Giving it a chance to cure ensures a good paint bond. And 28 days is exactly what the Brick Industry Association recommends.
Whatever paint you choose, it should help keep water from penetrating the surface while allowing water vapor to escape. For that reason, use latex or cement-based paint. Paints to avoid include oil, alkyd, rubber and epoxy. They won’t allow trapped moisture to escape.
Before painting, make sure surface grime and deposits have been removed and use a primer suitable for brick.
In your case, why not have the walls repaired with the right type of mortar but hold off on the paint? You can always offer that to sweeten the deal. After all, you were already planning on spending the money.
And if they’d prefer the natural look of brick, you can always agree with them and save the expense.
About the Author
An accomplished woodworker and carpenter, Scott Gibson is the former editor of Fine Woodworking magazine, and a former editor at Today’s Homeowner and Fine Homebuilding magazines. He also is former managing editor of the Kennebec Journal, a daily newspaper in Maine.
Posted on 12/31 at 06:49 PM