The influence of different creosote process parameters on penetration, retention and bleeding on glulam
F G Evans
Different process parameters were used to treat Scots Pine glulam beams with creosote. Parameters like pre-heating, pre-pressure time, pressure and pressure time were changed. Most treatments gave a full or almost full penetration of creosote into the sapwood, but the uptake of creosote in the sapwood varies.
All samples, except the one with poor penetration, showed heavily bleeding of creosote for about a year before the creosote hardened.
To get a good protection of the glulam without bleeding, it has to be double-treated. The lamellae have to be copper impregnated before gluing and the beam must then be treated with a creosote process as C (short pressure time) in part 1. The inner sapwood that will be untreated with creosote will then be protected by the Cu-preservative.