H&L Half-Log Log Siding Technical Bulletin

The H & L Half-Log™

The H & L Half-Log™ is an engineered wood product that combines pre-finished log siding, insulation and sheathing into a single application step. The first log siding design option consists of an extremely strong outer skin made from Aspen wood fibers, with a cedar-embossed surface. This skin is laminated under heat and pressure to a molded core of expanded polystyrene (EPS), reinforced with an oriented strand board (OSB) back. The second log siding design option features a thick, natural veneer outer skin laminated to a smooth hardboard veneer over the EPS core. Knotty Pine natural veneers are available. Using the best structural adhesive and aerospace laminating technology guarantees a highly-durable bond, which enables shipment of a quality log siding product every time. The cedar-embossed hardboard veneers are tough garage door skins with improved water resistance, weatherability and strength. A stain is applied at the factory on the face and edges of the veneer to protect the wood until the final top coat can be applied in the field. Following H & L’s natural veneer topcoat maintenance schedule activates the 15-year warranty. EPS neither contains nor uses ozone-damaging blowing agents in its manufacturing process. This stable insulating material is also 100% recyclable for non-structural applications such as packaging.

The H & L Half-Log has been subjected to rigorous testing at the University of Minnesota’s Natural Resources Research Institute (NRRI). Glue bond performance and weathering characteristics were evaluated in the laboratory following International Conference of Building Officials (ICBO) guidelines for building code acceptance for exterior wall coverings. To test the H & L Half-Log’s resistance to severe weather extremes, the NRRI subjected representative samples to ASTM D-1183 RESISTANCE OF ADHESIVES TO CYCLIC LABORATORY AGING CONDITIONS. Five cycles were completed, although only two are necessary to determine bond quality. The weathering characteristics were determined by placing 24 H & L Half-Log samples in a dual carbon-arc weatherometer for 2,000 hours, using the guidelines of ASTM Method G23-1981. An independent lab conducted R-Value tests using the methodology in ASTM: C236-89 STEADY-STATE THERMAL PERFORMANCE OF BUILDING ASSEMBLIES BY MEANS OF A GUARDED HOT BOX. Test results dated November 13, 1992 rated bond performance and weathering performance as excellent. In non-seismic areas, the H & L Half-Log can be used as structural sheathing with prescriptive corner bracing (let-in 1 x 4 bracing is recommended).

The H & L Half-Log has a Class III (C) flame spread rating. The actual performance R-value, based on guarded hot box testing at an independent laboratory, is R-7 for the 10” diameter Half-Log siding, R-8 for the 12” diameter Half-Log siding, R-9 for the 14” diameter Half-Log siding and R-10 for the 16” diameter Half-Log siding(values at 75 degrees Fahrenheit). An 8 foot length of the 10” size weighs only 14 pounds, the 12” diameter weighs 17 pounds, the 14” diameter weighs 22.5 pounds and the same length 16” Half-Log weighs 27 pounds. The H & L Round Insulated Corner Post comes in a standard length of 8 feet and weighs 22.5 pounds.

The natural veneer product is available in 8’ lengths only (94" actual). The 10” Half-Log has a stack height of 8”, the 12” Half-Log has a stack height of 10”, the 14” Half-Log has a stack height of 12”and the 16” Half-Log has a stack height of 14”. The Embossed Hardboard H & L Half-Logs are the same as the natural veneer half-logs in lengths and stack height. All half-logs should be stored flat and off the ground. Opened bundles should be covered to enable protection from dirt and moisture. Bundles are individually protected with lumber wrap prior to shipping. In addition, three corner systems are available: an insulated round post, an insulated square post and a solid pine saddle-notch. Standard bundle sizes are:

  • 10” log siding size 70 pieces/bundle 365 SF = 1 bundle*
  • 12” log siding size 44 pieces/bundle 287 SF = 1 bundle*
  • 14” log siding size 27 pieces/bundle 211 SF = 1 bundle*
  • 16” log siding size 24 pieces/bundle 219 SF = 1 bundle*

    * Based on 94" lengths

The H & L Half-Log siding can be utilized in new construction as well as in the retro fit market. H & L Half-Logs are adaptable to many new construction techniques, including: wood-frame stick-built, steel frame, masonry (conventional and insulated forms) and structural insulated panels. When wrapping a new frame structure with an air infiltration barrier and wind bracing the corners, the H & L Half-Log siding can be fastened directly to the studs (check local requirements). All-weather deck screws from 1-5/8” to 2-1/2” in length are recommended for fastening the log siding.

When installing the log siding, always fasten at the top, slide the next log over and lock it in place. The bottom course of log siding has a special cut to fit over the Composite Starter Strip. When the logs lock together, the row of fasteners becomes hidden and protected from the elements. Drive the fastener straight in near the bottom of the flange (Figure 1), through the full width so the locking groove remains intact. Wrap windows and doors with H & L Pre-Stained Cedar Trim and fasten with Olylog Screws (Figure 2).

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