Installation Tips for Fluid-Applied Air Barrier Systems

Fluid Applied Air Barrier Installation

You’ve heard it time and again. When properly installed, fluid-applied air barrier systems can be a good choice for building enclosures. What you may not have heard about is how to ensure proper installation.

Unlike sheet membranes, fluid applied membranes require a lot of attention to installation detail to deliver the performance that is desired.  The quality of a fluid applied membrane is primarily determined by the installer where the quality of a sheet membrane is controlled at the factory.

If you are using a fluid applied membrane you should consider interviewing the contractor and even visiting the jobsite to make sure the membrane is being installed properly.

Fluid-Applied Air Barrier Installation Checklist

1) Make sure your equipment is clean. You wouldn’t want a barista to use a dirty nozzle to make your coffee, or a restaurant to wipe down its tables with the same rag used to dry clean plates. Contamination can interfere with the application of the product, the product performance, and even with the machine’s function. You should refer to the cleaning instructions that came with your specific machine for details. Sometimes, it’s necessary to take apart the machine by hand to clean parts of the pump. Make sure that the machine is functioning well and that the product is not contaminated before you apply it to the building.

Likewise, clean up the power roller or spray gun pump system after you are finished. Old material shouldn’t be left in the pump mechanism, especially if you plan to use the machine for a different task next time.

Most products will have a recommended hose and tip size if you are using a sprayer.

2) Use even pressure and use the recommended pressure or settings. The fluid must be applied uniformly throughout the building. All fluid-applied products come with a recommended thickness. It’s very important to check that the thickness remains consistent, because variations could lead to ineffectiveness, cracks, or gaps in the system.

3) Hire a trained professional to install the system. Many companies will train and certify installers for their proprietary product. Because each fluid-applied system differs from the next, it’s crucial that the installer you hire knows how to install the product line you choose for the building.

4) Familiarize yourself with the UV exposure capacity of the product and the recommended temperature ranges (both ambient and surface). Make sure the product can handle the construction schedule and site climate. Also remember to protect the product from the sun if you’re going to leave it at the construction site. Most products cannot be stored, even in a sun-protected place, for very long.  If construction will outlast the life cycle of the product, planning to replenish your stock beforehand will save a lot of trouble later on.

5) Find out whether the product requires a primer or sealant as part of the application process.

6) Make sure you know what area each component of the air barrier system is for. If the company includes a separate product for a specific building area, they’ve probably done so for a good reason. The main fluid-applied formula is meant to easily and consistently cover walls and other large areas and may not be suitable for detail areas such as around windows and doors.

7) Don’t overapply the product. It’s tempting to think that more product equals more effectiveness or more coverage, but companies recommend a thickness that is based on the product’s ideal performance. Moreover, the thicker the layer is, the more likely it is to shrink at a rate that could cause permanent damage to the enclosure.

Two other reasons that applying the membrane to the correct thickness:

As thickness increases, permeability decreases.
As thickness decreases, water hold-out decreases.

Regular use of a wet film gauge during the application process is critical to achieving manufacturer’s recommended thicknesses.

8) Make sure that the substrate to which you are applying the product is clean. A dirty or inconsistent surface will make the coating uneven or unreliable.

9) Critical detail areas like window flashing are done with sheet membranes to complete continuity.

10) Be careful! Most of the fluid-applied products can be hazardous if ingested or inhaled. They may also be highly flammable. Always follow all safety procedures, including procedures relating to product disposal.

11) Be careful spraying in stronger winds or greater heights.  Over spray has caused more than one installer to pay for cleaning of cars in neighboring parking lots.

Remember to be prepared and to know enough beforehand about the product you choose for the project. Paying attention to the little details and having procedures in place before construction begins will save a lot of time, money, and energy later.

To avoid all this attention to detail,  you can also consider a fully adhered membrane such as DELTA®-VENT SA.

Dörken delivers innovative, high-performance air and moisture barriers for commercial and residential construction sold under the DELTA® brand name. A North American manufacturer based out of Beamsville, Ontario, Dörken Systems Inc. is a subsidiary of Ewald Dörken AG, a leading European developer and manufacturer of waterproofing and drainage products sold worldwide. Dörken is known for delivering premium products while providing educational programs and full technical support. For more information, call 1-888-433-5824 or visit