What Is Parallel-Strand Lumber?
What Is Parallel-Strand Lumber?
Parallel-strand lumber (PSL) is an engineered wood product made by bonding strands of wood together in parallel using waterproof adhesives with a phenol-formaldehyde base.
This allows for the creation of extremely strong timber that can support large loads and span long distances, making it ideal for use in components such as beams and columns.
To ensure stability and strength, the strands used to form PSL are typically composed of select waste materials sorted according to size and stiffness requirements to remain aligned during the continuous press process.
The result is an environmentally friendly, cost-effective solution for construction projects with stringent structural integrity requirements.
What Is The Difference Between PSL And LVL?
The primary difference between PSL and LVL is cost: LVL is generally cheaper than PSL.
Additionally, LVL can be fabricated in narrower beam widths (1 ½, one ¾”) than PSL, and multiple plys of LVL can also be nail-laminated together to form a giant beam for increased strength that surpasses the strength of a single piece of PSL.
Available sizes, strengths, and stiffness are similar but tend to differ in price.
Who Makes Parallel-Strand Lumber?
Parallel-strand lumber is a product invented, developed, commercialized, and patented by MacMillan Bloedel (now Weyerhaeuser) and marketed under the brand name Parallam.
It offers superior strength, stiffness, and dimensional stability over traditional lumber products. As the world’s only commercially manufactured parallel-strand lumber, it is popular for its structural integrity in residential and commercial construction applications.
Its unique combination of long and short strands ensures maximum strength for its weight class.
It is suitable for applications where lighter-weight materials are desired, such as floor joists or roof trusses.
Can PSL Be Used Outside?
Yes, PSL, also known as Pressure-Treated Lumber, is a popular choice for exposed woodwork due to its range of available wood grains and compatibility with stains.
Furthermore, it’s treated for added moisture resistance, making it suitable for exterior use in damp environments.
This ensures that neither this durable material’s appearance nor function is compromised regardless of the environment.
How Far Can A PSL Beam Span?
A PSL (Parallel Strand Lumber) beam can span up to 60 feet, as specified by the span and load tables of this guide. However, Parallam® PSL beams are available in lengths up to 66 feet, so a further 6 feet can be easily achieved with this type of beam.
This makes it ideal for wider applications where more length is needed. Additionally, because of its strength and durability, it can carry greater loads over longer distances than regular timber beams, making it the perfect choice for many construction projects.
How Much Does A PSL Beam Weight?
A PSL beam typically weighs 76.60 lbs and has a thickness of 3-1/2″, width 7″ and length 10″.
These dimensions make it an ideal choice for many applications as its size makes it easy to manoeuvre and install in tight spaces.
Can PSL Beams Be Ripped?
No. Parallam® Plus PSL beams cannot be ripped; they must remain in their original cross-section and should not be re-sawn in either depth or thickness.
This is to ensure that the beam remains structurally sound and fit for purpose, as changes to the cross-section can weaken the beam’s structure.
Furthermore, re-sawing the beam would remove its integral plywood layers, damaging its strength and longevity.
Additionally, any attempt to rip a Parallam® Plus PSL Beam could result in a dangerous kickback from a saw blade or other injury from tools used during the ripping process.
