laminated bamboo lumber is made by using bamboo strips laminated together to form a plank or mutiply of planks glued once again to form a block, it is sort of a dimensional lumber, or S4S (Smooth 4 Sides) bamboo. this lumber has gone through a planer, which makes the lumber perfectly smooth on all 4 sides and precisely in fixed sizes, with minimum size tolerances. and the lumber can be in sqaure edges on all 4 sides, or with rounded edges lengthwise.
there are 2 different types of bamboo lumbers, namely indoor grade bamboo beams and outdoor grade bamboo lumbers.
indoor grade bamboo beams,
indoor grade bamboo beams are made by using ure-formaldehyde glue, and hot pressed at 100 centigrade, available in both carbonized and natural colors. length options are: 2000mm, 2440mm or finger jointed or edge jointed to 5800mm, 9600mm etc. width options ranging from 12mm to 200mm, thickness ranging from 12mm to 100mm. indoor bamboo beams like 2440x50x25mm can be used for wall covering, big beams like 2900x120x70mm,2900x150x100mm can be used for door frames, window frames etc. or used as structural beams.
outdoor grade bamboo lumber
sthe technique and production process for outdoor grade bamboo lumber is totally different from indoor bamboo beams. let's look at the differences below,
1) outdoor bamboo lumber is made by using phenol-formaldehyde glue, we apply the glue to the bamboo strips first and wait 24 hours to let the glue get dry before hot pressing.
2) temperature on the press machine must be higher than 130 centigrade, which is the lowest temperature for phenol-formaldehyde glue to work and start to bond the bamboo strips together.
3) for indoor bamboo beams , we need to hot press at 100 centigrade right after ure-formaldehyde glue being applied, while the glue is still wet. if we wait 24 hours, the glue will be hardened, and of no use.
4) for outdoor bamboo lumber, we must wait 24 hours after phenol-formaldehyde glue being applied, and hot press at minimum 130 centigrade, which makes the glue start to work and bond.
in most cases outdoor bamboo lumber is always darker in color compared to indoor bamboo beams. and outdoor bamboo lumber comes in 2900mm, 5800mm or even longer length like 9600mm.
exterior grade bamboo lumber mainly used as columns for constructions, buildings, used in outdoor conditions.