Karri timber is a unique, high density and extremely hardwearing Australian hardwood timber with distinctive red hues. Karri is a Class 2 above-ground timber suitable for a variety of indoor and outdoor applications. Because of its strength, it can be used in structural applications, often featured in indoor and outdoor joinery.
Karri is a Class 2 above ground durable hardwood timber, available in unseasoned sawn and kiln dried (KD) beams and decking. Beams are strength rated to F27. The timber's high density and durability makes it a versatile and extremely hard wearing timber. Its density also makes it fire resistant - BAL's 12.5, 19 & 29. Karri is prone to light surface checking if exposed and not oiled. It is advisable to seal the timber as soon as possible after dressing and installing.
Karri has a distinctive appearance, with colour tones ranging from light-pinks to deep reddish/browns as well as whitish sapwood streaks. Karri has a long fibre and an interlocking grain which adds strength & reflects light to give great lustre and depth to its appearance, while highlighting its natural characteristics.
Karri finishes reasonably well, however, like other high density hardwoods, because of its density and heaviness it can be difficult to work with. It requires pre-drilling when nailing and doesn't accept glue readily. When moulded it may require additional sanding. Cutting tools need to be kept sharpened. Porta recommends using oil-based paints and stains as Karri doesn't accept water-based paints/stains readily. Karri can be painted with an oil based undercoat/primer then apply an acrylic top coats, however its colour and grain offer an attractive exposed timber.
How do I prevent Karri from checking and cracking?
In exposed applications, we recommend applying a coat of oil-based preparation to 'feed' the timber', which will slow down the tendency to expand and contract and minimise any surface cracks or checking.