Nominal 100 micron thick, 1 cm wide and 10 cm long radial/ longitudinal Pinus nigra microtome sections were dried and treated with dimethyl dichlorosilane in the vapour phase. The same experiment was repeated with previously water-leached specimens. The chlorosilane readily reacted with wood hydroxyl groups to form silyl cellulose. The silanation product was quite resistant to the effects of prolonged water leaching and is quite durable too.

2×2 cm radial-tangential 6 mm thick transverse wafer specimens of the same species were treated in both vapour and liquid phases. Water repelling effectiveness of the specimens were measured by time to half swell (Tj). ‘

Silanation by both vapour and liquid phases slows down the sorption process by over 70 times the normal process. The maximum equilibrium swelling is also brought down to 72.5% in the case of liquid phase and 75.0% in the liquid and vapour phase respectively. Conventional water repellents slow down the rate of water uptake but do not change the total sorption. This establishes the superiority of silanation over conventional water repellents in decreasing the maximum equilibrium swelling of wood in contact with moisture.