Hemlock's proven strength and excellent treatability have made it the preferred species for sill plate components in Zairai home construction. Pressure treated Hemlock delivers a high measure of protection against insect attack and decay.
Dodai from Interfor is graded specifically for sill plate where bending strength and compression properties are of prime consideration. The standards for straightness, and other characteristics affecting stability, are also strictly controlled.
Minimum Standards:- Open face knots are limited to 40% displacement to ensure high bending strength and resistance to compressive forces.
- A maximum of 50% displacement for enclosed knots ensures adequate strength and allows for good notching surfaces.
- As with all Zairai components, stability is a concern. Shipments are restricted to a minimum of 80% FOHC (Free of Heart Centre), no compression wood in damaging form is allowed, and localized grain deflection cannot interfere with the practical use.
| Thickness | Width | Seasoning | Lengths | |
|---|---|---|---|---|
| 90mm | x | 90mm | KD or Green | 4.0m (2.4 - 4.0m available) |
| 105mm | x | 105mm | KD or Green | 4.0m (2.4 - 4.0m available) |
| 120mm | x | 120mm | Green | 4.0m (2.4 - 4.0m available) |