LVLs Rated For Interior (Dry-Use) and Exterior Use

At Team Engineering, we typically specify engineered lumber products manufactured by Weyerhaeuser. When considering beams spanning long distances and where built-up dimensional lumber isn’t practical, we immediately turn to LVL beams. Microllam® LVLs and TimberStrand® LSLs are appropriate for dry-use applications where the beam is not going to be directly exposed to precipitation. These beams cannot be pressure treated.  Neither product is suitable for the pressure treatment process due to material density and adhesive content. Also, some wood species used in their production may not be able to properly absorb the treatment chemicals.

The best choice for exterior use is the treated Parallam® Plus PSL. The Parallam® Plus PSL is made from Southern Pine which is a species that can be easily treated.

Parallam® Plus is typically specified for outdoor decks or applications where the member is exposed to direct rain or snow. Applications where wood members are exposed to atmospheric moisture only (porch roof framing without a finish ceiling or floor joists over a crawlspace, for example), are generally considered ‘Dry Use’. Dry use is defined as an environment where the in-service moisture content of the member is less than or equal to 16%.

Parallam® Plus PSL Beam

If your building project requires an LVL beam, please feel free to reach out to us at Team Engineering for sizing and selection of the correct product for your particular use.

William Fitzpatrick

Project Manager