Weyerhaeuser Company

09/27/2021 | News release | Distributed by Public on 09/27/2021 12:52

Holes in Parallam® PSL - How to get it right


When designing a home, identifying where to run plumbing and electrical can be a real challenge! Redesign? Reroute? Cut holes? If the surprise demand for a hole occurs during rough-in, you may have more options than you think. With Parallam® PSL, the addition of a hole is a straightforward and simple process.

Parallam® is an extremely strong engineered wood product (EWP), allowing long spans for open floor plans without intermediate posts or columns. Parallam® also has a warm and unique grain, perfect for applications with exposed beams. This strong and straight EWP arrives to job sites in solid sections for easy assembly and has an impressive capacity for both shear and moment.

The quickest way to determine what kind of holes can be added to a Parallam® product is to look at Weyerhaeuser's specifier's guide for Trus Joist Beams, Headers, and Columns. A unique guide is available for the United States, East Canada, and West Canada. The documents can be found in Weyerhaeuser's document library, and are numbered TJ-9000, TJ-9500, and TJ-9505 respectively. The section on Allowable Holes illustrates the type of holes and their locations, which can be easily added to a Parallam® member. If the member is designed to sit in a beam orientation and subscribe to a uniform load, the guide will direct the reader to where up to 2" round holes can be added, no questions asked.

In cases where a hole diameter up to 2" is not adequate, or the hole must be placed outside of the specifier's guide allowed hole zone, ForteWEB will allow you to design a hole in Parallam® as well as provide information about design values and capacities for both the member, and the hole. Although the allowable hole diameter depends on the depth of the beam, a quick design in ForteWEB shows that at 2/3 the product depth, two enormous 12" holes can be added to a 15ft. 7" x 18" 2.0E Parallam® product. In this example a 12 PSF Dead + 40 PSF Live load has been applied.

For questions about adding holes to Parallam® members, consult Weyerhaeuser Technical Support. Adding holes to a Parallam® PSL beam or header can be done in a pinch without the headache. Checkout Weyerhaeuser's specifier's guides and ForteWEB to find a design that will work for your jobsite.