I-joists are strong, lightweight, “I” shaped engineered wood structural members that meet demanding performance standards. I-joists are comprised of top and bottom flanges, which resist bending, united with webs, which provide outstanding shear resistance. The flange material is typically laminated veneer lumber (LVL) or solid sawn lumber, and the web is made with plywood or OSB. The robust combination of structural characteristics results in a versatile, economical framing member that is easy to install in residential and light commercial projects. (https://www.apawood.org/i-joist)
I-joists are used extensively in residential floor and roof framing. They are ideal for long spans, including continuous spans over intermediate supports. Because I-joists are straight and true, it’s easier for builders to avoid crowning and maintain a level framing surface. In addition, wood I-joists are typically stocked and readily available in depths that meet the needs of residential framing. (https://www.apawood.org/i-joist)
PWI-joists are a balanced product and do not have a top or bottom like an unbalanced glulam. However, the web does have pre-punched knock-outs that are closer to one flange. The knock-outs are easier for electricians to use when located near the bottom of the installed joist.
PWLVL billets, originally 48” wide when manufactured, are ripped into narrower widths, typically from 3-1/2” up to 24”, across the 48” wide width. Each piece is the same grade as the original billet. A 1-3/4” x 24” can be ripped to a narrower width, including 18”. The capacity of the new beam would be based on the new size. An 1-3/4” x 18” 2.0E LVL ripped from a 24” beam would have the same design values as one that came straight from the factory in that size. PWLVL cannot, however, be planed or sawn to reduce thickness.
PWLVL, produced for the North American market, has a wax coating applied to mitigate the rate of moisture absorption during storage and construction. This coating will likely make it difficult to apply paint or spray foam insulation directly on the LVL. PWT’s coatings supplier suggests that it would be best to discuss options with the paint supplier for a primer (likely solvent-based) to improve applicability. Inform the paint supplier that the coating contains paraffin wax (hydrocarbon/synthetic wax).
Pacific Woodtech Laminated Veneer Lumber (PWLVL) is produced to specific tolerances based on manufacturing equipment capabilities. Due to the manufacturing processes there may be slight variations between the product and nominal dimensions. This slight deviation in dimensions is called tolerance. When PWLVL leaves the manufacturing facility, its dimension tolerances are within the manufacturer’s limits and the product moisture content is between 6-10%.
PWLVL may swell, shrink, and change shape in response to moisture and adverse weather, even with the additional protection of factory applied sealants. Moisture content for in service conditions will vary widely.
PWLVL products should be protected by keeping the products wrapped, off the ground, stacked, and supported appropriately. Using these guidelines will help keep product clean, shed rain, and promote air circulation to dry off any incidental moisture.
For additional storage and handling information, see: E705 Proper Storage and Handling of IJoists and LVL
Don’t panic! There is technical staff available to help you. Contact the supplier you purchased the product from. They will help you through the process. Expect to fill out a damage report form, take measurements, and send pictures. They will run a calculation and let you know how to proceed.
Pacific Woodtech has teamed up with Kop-Coat to create the only commercially available fully treated LVL. Called “TRU-CORE® technology,” this process was developed to move treatment chemicals through wood; the migration process is accelerated when energy, such as heat from an LVL press, is added.
The difference is that traditional processes use VOCs and/or incising to drive treatment into only the outer 0.4” perimeter of a wood member, while the patented TRU-CORE® technology can drive treatment into the entire member (no gradient) without adding regulated mineral solvents or water-based drivers, which can affect strength and/or void warranties in engineered wood products.
PWT Treated LVL can be used in exterior construction above ground applications (UC3B) and for components that are difficult to maintain, repair, or replace and are critical to the performance and safety of the entire system.
Any above-ground interior or exterior use such as deck beams, deck joists, deck columns (when on piers of 8” or greater in height, with a 1” offset). It is also a great product for treated sill plates, when used with a foam gasket for separation from the concrete, which is required by code. PWT Treated LVL should not be used in “ground contact.”
Douglas-fir is a “refractory species,” which means it has different anatomical properties, such as pore size and structure, making traditional treating processes difficult. However, when you look at the physiology of dry Douglas-fir, you will see that with some modern technology, it can be treated quite easily.
Kop-Coat’s TRU-CORE® technology offers full penetration of Douglas-fir using modern preservatives. See ESR-3834 for additional details.
Many western species are considered refractory species.
No, the treatment continues to normalize for about 24 hours after the LVL is pressed. After that time, the process has stabilized within the product.
Kop-Coat developed the technology, who had applied for their first patent on this in 2004. To date, there are over 90 commercial wood treatment penetration programs across the globe.
Other companies have tried to develop similar penetration technologies but have failed.
All organic molecules degrade over time – regardless of treatment process. The ones selected for TRU-CORE® technology retain their strength for 30 to 60 years in use – this is a significant improvement over traditional treatment processes where only the outer layer of wood fiber is treated.
The LVL will also be stamped/marked “PWT TREATED” and will have a muted olive colored sealer that is different than the standard Pacific Woodtech “honey brown” sealer on untreated LVL.
There are no solvents or VOCs in the treatment, so the genuine smell of wood is retained.
Yes, the active chemicals used in the treatment process are below EPA levels for indoor use.
The risks associated with touching/handling PWT Treated LVL are no worse than those of untreated LVL.
Always wear proper PPE per the safety data sheet
The hazards are no worse than those of untreated LVL.
Per the SDS: Ingestion is not an expected route of exposure. Rinse mouth. Immediate medical attention is not required.
No, since PWT Treated LVL is treated throughout the piece (no gradient), re-treatment is not necessary. However, it is recommended to recoat cuts with a sealer or paint to minimize swelling, as moisture will wick into end-grain fibers more quickly than edges and faces.
Yes, PWT Treated LVL can be stained or painted.
Proper flashing is required over ledger boards to meet code. Refer to building code requirements for ledger boards.
Flashing (metal or plastic) or approved flashing tape is required on any upward horizontal surfaces of the PWT Treated™ LVL to satisfy the warranty.
Flashing tape must have passed design standard AAMA 711-13, Level 3, Class A, perform in high and low temperature extremes, and have minimum UV protection of 120 days exposure.
Deck drainage systems that cover upward horizontal surfaces of PWT Treated™ LVL joists and beams, preventing wetting from occurring, are acceptable substitutions for flashing on the joists and beams.
Failure to use proper flashing, approved flashing tape, and/or proper deck drainage systems will void the warranty.
Failure to apply flashing in accordance to the manufacturers’ written installation instructions and as required by code will void the warranty.
Cladding is allowed if it will not trap moisture, as this will reduce the performance and life expectancy of even treated wood products.
PWT Treated LVL can be disposed of in the same manner as untreated LVL.
ACQ, CA, and MCA are chemicals used for post-manufacture, pressure treating of wood products. PWT Treated LVL uses a PTI based system. PTI stands for Propiconazole (fungicide), Tebuconazole (fungicide), and Imidacloprid (Insecticide). Our PWT Treated LVL has twice the PTI retentions required for UC3B, with no gradient that you would see in pressure treated lumber.
PTI is very common. It has been around for over 20 years. These PTI protection systems are used for many types of wood products including decking, fencing, siding, windows, sheathing, flooring, framing and other wood and wood-based building materials.
Yes, PWT Treated LVL qualifies as a ‘green’ building product. Its materials are sustainable, wood is a renewable resource that stores carbon, and its regulated toxins are well below EPA tolerances. PWT Treated LVL also qualifies as a no added urea-formaldehyde (NAUF) and ultra-low-emitting formaldehyde (ULEF) product.
The Green Verification Report documents compliance with recognized green building standards.