What’s the Most Effective Drip Edge Design?

Drip edges for masonry cavity walls. Not what many people would consider a fascinating topic, and something most designers and masons may not give much thought to. But specifying and installing the right drip edge can have a dramatic effect on the longevity and beauty of a masonry veneer.

Drip edges are instrumental in directing water away from the veneer face and ensuring that water that flows out of the weeps doesn’t get drawn back into the cavity under the flashing via capillary action. The ability of capillary forces to draw water in under the flashing when drips are not used is why we strongly recommend the use of drip edges. We realize some designers don’t like the look of a metal drip edge, and they may specify no drip edge and holding the flashing back from the brick face slightly to keep the mortar joints looking consistent. Unfortunately, this design almost guarantees water damage because is sets up perfect conditions for water to be drawn in under the flashing. Before deciding to omit a metal drip edge, we strongly suggest the designer weighs the cosmetic and structural damage that water under the flashing can cause against the aesthetic concerns of a visible drip edge.

Building Science Labs conducted a test of the effectiveness of several drip edge configurations. They found that both the size and shape of the drip edges made a significant difference in the water shedding ability of the drips, and in their ability to channel water away from the veneer face as opposed to letting it run down the face or be drawn back into the cavity under the flashing. One of the study’s conclusions is: “Whether or not the edge of the drip edge was hemmed had the greatest impact on the shedding of water from the surface of the wall.”  Mortar Net Solutions drip edges are all hemmed to provide the best performance. Click here to learn about available Mortar Net Solutions drip edges.

Click the link below to see the study.

http://www.buildingsciencelabs.com/effectiveness-drip-edge-designs/