FIND A CONTRACTOR BUYER'S GUIDE
BECOME AN INDUSTRY PARTNER
MCAA Logo
MEMBER LOGIN JOIN
NEWS
Join Us For The 75th Anniversary Midyear Meeting Sep 7-11 ↗

Updating Brick Veneer Ventilation for Modern Construction

Words: Jimmy AdamidisMasonry structures are known for having high durability, which is why they are built to last for 100 years. Current building codes emphasize energy efficiency, which has made influential changes to masonry veneer wall systems. The two most influential changes are the additions of continuous insulation and air barriers into the masonry cavity. These additions greatly enhance energy efficiency. However, the addition of continuous insulation causes masonry cavities to lose air space, frequently as much as 50%. This is the new era of brick veneer, the era of smaller air spaces in veneer walls. Improper ventilation systems based on old technology can cause excess moisture, affecting the durability and longevity of the structure. Therefore, properly detailing these walls is crucial.

There are two keys to drying in veneer cavities: drainage and ventilation. Drainage requires an opening or weeps at the bottom of the wall to allow any incidental moisture to escape the veneer system. Ventilation requires an opening in the cavity large enough to allow air to enter, flow through the cavity, and then exit. Unfortunately, mortar bridges can block the ventilation and prevent the drainage system from working properly.

Mortar bridging in brick veneer walls occurs when ventilation spaces are too thin to stop mortar from clinging to the interior wall. These mortar bridges create a space for water to collect, which impedes ventilation and drainage. In this scenario, traditional mortar collection devices are useless, because the mortar dam is formed above the bottom of the wall. The solution is to use full wall drainage systems.

Keene Building Products, along with Architectural Testing Inc., performed a test of several 1-inch brick veneer walls with 1 inch of air space to compare the performance of drainage and ventilation products in a cavity wall. Wall 1 consisted of Product A, a dovetail mortar collection device that utilized three weep vents in the top and bottom courses of the brick. Wall 2 included Keene’s CAV-AIR-ATOR™ full drainage system and three Driwall™ weep vents in the top and bottom courses of the brick. Each wall was constructed with a single course of bricks with a 1-inch cavity. Walls were constructed according to standard building practices using the same materials; all products were installed to manufacturers’ recommendations.

Air Infiltration: ASTM E 284-04, Standard Test Method for Determining the Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen. Testing was conducted at 1.57 psf (25 mph) and 6.24 (50 mph) positive static air pressure difference.
Table 1 – Air Infiltration Test Results
&nsbp; 25 mph 50 mph
Wall 1 (Product A) 15.8 cfm 37.9 cfm
Wall 2 (CAV-AIR-ATOR) 24.2 cfm 51.4 cfm
Water Drainage Performance Test: This test introduced five gallons of water into each cavity wall and captured the amount of water drained out of the weep vents.
Table 2 – Water Drainage Performance Test Results
&nsbp; Amount of water Drainage time Collected
Wall 1 (Product A) 5 gallons 10 minutes 4.62 gallons
Wall 2 (CAV-AIR-ATOR) 5 gallons 10 minutes 4.70 gallons
It can be seen how changing from a simple mortar collection device to a full wall system can increase the drying potential of the wall. In these tests, Wall 2, the full wall system, increased ventilation by 75% when compared to traditional mortar collection devices. Furthermore, unlike traditional products, full wall products like the CAV-AIR-ATOR do not require thick cavities in order to perform.

As we build our buildings to be more energy efficient, we reduce the air space behind the brick veneer. Unfortunately, the need for proper drying does not decrease as we move toward energy efficiency. Therefore, ensuring that we maintain an unimpeded air space is critical. Keene Building Products endorses the use of a full wall ventilation and drainage product in brick masonry applications with less than 2 inches of open air space. By installing this type of product in a brick veneer wall, you are eliminating all mortar bridging and dramatically increasing ventilation, while maintaining the energy efficiency of the structure.
 0
Chairman's Message: REFLECTIONS SPANNING SEVENTY-FIVE YEARS
September 2025

MCAA has been posting lots of wonderful old photos from decades of records as we celebrate our 75th Anniversary. Many of these photos are black and white and show people at our MCAA events with men wearing suits and ties while the women wore dressy gowns

Dick Dentinger
Chairman’s Message
Read More
Business Building: What Are You Doing To Develop Future Leaders?
September 2025

When I ask my coaching clients if they have anyone in their construction company who could potentially move up from field superintendent to estimator or project manager, the typical answer is “No!” The same answer is usually given when asked if they have

George Hedley
Business Building
Read More
Building More: Smoke Signals or Fire Extinguishers
September 2025

Ever watch a hot-potato game break out on your jobsite? It usually starts small. Somebody spots a crooked door frame, mutters, “I’ll make a note,” and flicks the issue to the next trade like it’s radioactive. By the time that frame comes back around, dryw

Corey Adams
Building More
Read More
MASONRY STRONG Podcast, Episode 27 Recap: Rob McKay, Chief Operating Officer at Instone
September 2025

On this episode of the MASONRY STRONG Podcast, Rob McKay from Instone joins the show to talk about his story as well as the processes and procedures of manufacturing natural stone. Getting Started in Masonry: Rob’s Story Rob entered the masonry field by

Justin Stengel
The MASONRY STRONG Podcast
Read More