I-joists are used for floor framing and roof rafters in residential and light commercial projects. They are comprised of LVL flanges and OSB webs, which is a very efficient use of wood fiber. I-joists are capable of longer spas than conventional lumber, easy to install due to their lightweight design, and uniform in size.
Laminated veneer lumber (LVL) is used in structural applications such as beams, headers, and hip/valley rafters. Because of how it is manufactured, it is available in lengths far beyond conventional lumber lengths, capable of carrying more load, and dimensionally stable.
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.