5/4x4 Red Balau Tongue & Groove Siding

A 5/4x4 Red Balau board weighs approximately 1.70 lbs per linear foot. Red Balau has a density of about 50-60 lbs/ft³, making it one of the densest commercially available hardwoods. Always factor weight into your structural and shipping calculations.

Yes — Red Balau is rated Durability Class 1 (Very Durable) and is naturally resistant to rot, decay, insects, and fungal attack without chemical treatment. It is naturally durable and performs exceptionally well in full exterior exposure including siding applications. While ground contact is possible, we recommend elevating Red Balau boards at least 6" above grade for maximum lifespan.

Red Balau outperforms composite in hardness (2,700 vs ~200 Janka), lifespan (up to 40+ years vs 25-30 years), and heat resistance. Unlike composites, Red Balau won't melt, warp in extreme heat, or fade significantly. While initial cost is similar ($8-15/LF installed), Red Balau costs less over its much longer lifetime. Composites do offer lower upfront maintenance.

Red Balau requires minimal maintenance. Without treatment, it naturally weathers to an elegant silver-gray patina over 6-12 months. To maintain the original warm brown color, apply a UV-inhibiting penetrating oil (like Ipe Oil or Penofin) once or twice annually. Cleaning involves periodic washing with a mild soap solution. No sanding, staining, or sealing is required for structural durability.

Red Balau is DIY-friendly with proper preparation. Key requirements: (1) Always pre-drill all screw holes — Red Balau is too hard for direct screwing. (2) Use only 305 or 316 stainless steel fasteners — standard hardware will corrode and stain. (3) Face-screw with stainless steel trim-head screws. (4) Allow boards to acclimate on-site for 5-7 days before installation. A compound miter saw with a carbide-tipped blade is recommended.

A nominal 5/4x4 Red Balau board has actual finished dimensions of 1" × 3.5" (25.4 x 88.9 mm). The "5/4x4" is the nominal (rough-cut) size — after kiln drying and precision surfacing, all hardwood lumber finishes slightly smaller. This is standard across the lumber industry, similar to how a nominal 2×4 softwood measures 1.5" × 3.5". Always use the actual dimensions (1" × 3.5") when calculating material quantities and coverage for your project.

We responsibly, legally, and ethically source all our Red Balau. We work only with suppliers who follow responsible forestry practices with full chain-of-custody transparency. Note: We are not FSC certified. Red Balau trees grow naturally in diverse tropical forests and regenerate well under managed harvest. The extremely long lifespan (up to 40+ years) means fewer replacements compared to softwood or composite alternatives, reducing long-term environmental impact.