Masonry Magazine July 2009 Page. 36
AIR BARRIERS
While each type of air barrier product will have its own installation procedure, there are a number of steps that should be considered in masonry construction, regardless of the product.
Specify flush masonry joints for the CMU backup, with joints completely filled.
Any excess mortar on the substrate and ties should be removed.
Mortar should reach the minimum cure period recommended by the air barrier manufacturer prior to installation.
Complete a full examination of the CMU backup substrate prior to installation, verifying it is clean and free of moisture.
Consider the weather conditions under which the air barrier assemblies will be applied and make changes accordingly.
Ensure any work by other trades that may penetrate through the air barrier system is in place and complete.
Prime the CMU backup according to manufacturer's recommendations.
Seal vertical and horizontal surfaces at terminations and penetrations.
Connect air barrier assemblies in exterior wall continuously to the air barrier of the roof, to below-grade structures, to windows, curtain wall, storefront, louvers, exterior doors and other intersection conditions and perform sealing of penetrations, using accessory materials and in accordance with the manufacturer's recommendations.
Plan accordingly for changes in substrate plane, through-wall flashings, control and seismic joints, and any other gaps to ensure continuous transitions.
During the installation and construction process, the membrane should receive appropriate protection at the end of each work day.
Do not allow materials to come in contact with chemically incompatible materials.
Do not expose membrane to sunlight longer than recommended by the manufacturer.
Always install materials in accordance with manufacturer's recommendations.
Prior to enclosing the assembly, inspect and repair any damaged areas of the air barrier system.
Conclusion
THE SUCCESSFUL INCLUSION of an air barrier system in building projects can be a rewarding experience for the designer and owner. Whether the project is commercial or residential even a multi-tenant building can reap benefits from the healthy environment, reduction in energy consumption, and increased building valuation. IMAS Jennie Farnsworth is an Atlanta-based writer and editor.