Issues In Exposed Brick Work

Rustic, idyllic, elegant or harsh – exposed brick can have multiple faces, depending on what color you have it and how you decorate around it. When done properly, brick walls can be a tremendous statement of style, but they have certain shortcomings that you should be aware of before you get down to hammering off the plaster.

Brick Wall Facts

One of the greatest problems with exposed brick in external walls is temperature and moisture control. 

1. Brick walls are never waterproof. Bricks and mortar are able to absorb a great deal of moisture in multiple ways and must be able to breathe to eliminate this moisture.
2. Water can enter through tiny cracks between the bricks and mortar. When mortar doesn’t completely fill the vertical joints between bricks, these “head joints” will allow water to flow.
3. Bricks and mortar have tiny passageways that like a sponge, suck water in … and release it quickly.
4. Older homes may experience leaks but this rarely causes problems. With two or three layers of brick, they can absorb a lot of water and when the sun appears, they will release the water back into the atmosphere.
5. Newer homes have a single layer of brick veneer. When not constructed properly with flashing and weep holes at the bottom of the brick wall, the trapped moisture may cause wood framing to decay and mold to grow.
6. Moisture is a problem in most climates as air conditioning creates cold air in warmer temperatures.

Solution to a Drafty Brick Wall

If there is no visible moisture/water problem along the floor next to the brick wall, then the current ventilation is working and we probably don’t want to alter air flow between the room and the exterior. We can only give recommendations – the ultimate decision always lies with the home owner when it comes to home maintenance and repairs.

1. Use a vapor-permeable barrier like Tyvek. It is designed to reduce air flow while letting water vapor from inside your home, migrate to the exterior.  These water repellents are designed to penetrate into the brick and mortar, coating the insides of their tiny passages while leaving the passageways open so the brick and mortar can breathe.
2. Don’t want to use a film forming sealant that creates a continuous barrier on the surface as this will stop water from getting in … and getting out! If you still want to apply a moisture barrier, please read Brick Leaks at Ask the Builder first.

Water seeps in through the mortar

First thing you should consider is a good exterior insulation to prevent water from getting in. Moisture will deteriorate the brick. Simply painting/sealing/staining it from the inside won’t work because it will not allow water to evaporate off since the surface is blocked. Eventually this will cause the paint to chip off and you see yourself in the same spot where you began, with less money in your pocket.

Brick pores, incomplete mortar joints, sills, copings and other gaps will allow water to get in. Find them, seal the exterior and then give time to your brick wall to dry off. Use a hot air cannon if needed (for at least 48 hours) and start the project only when the brick is completely dry.

What products to use and how to prep brick

1. Normal brick shouldn’t affect the durability of paint because most of them are neutral. However, it’s best to go for an alkaline-resistant primer — the risk of long-term or immediate damage is less likely. For the exterior you should use a porous paint so that the brick can breathe, and a breathable latex would be a great choice.Regarding brick preps, it’s quite simple if done correctly. Use soap and water to clean it up. Don’t go for acid solutions, they might do more damage than you think (and could result in paint chipping, as well). You’ll need to get rid of efflorescence — that white residue which sometimes appears on brick, wash off dirt and eliminate mold with weed killer. Then seal any cracks you may find. If you decide to paint it up, throw a water repellent before the conditioner and the primer, but make sure you allowed a few days for it to dry off.
2. If you love the look of exposed brick but don’t want to get involved in major demolition projects, there are still some options to go for. One solution is to use thin brick veneer or tiles imitating brick, but this involves certain “heavy” works, too. If you’re on a tight budget, faux brick wallpaper will do, and believe it or not, they are so realistic today that people will hardly tell the difference unless they come up really close to the wall.