control (CNC) allows architects and designers to cut glued laminated timber into unusual shapes with a high degree of precision. CNC machine tools can utilize up to five axes, which enables undercutting and hollowing-out processes. The cost-effective CNC machines carve the material using mechanical tools, like a router. Advantages There are several advantages to using glulam in construction: Size and shape - By laminating a number of smaller pieces of lumber into a single large structural member, the dimensions of glulam members are only limited by transport and handling rather than the size of a tree like sawn lumber. This also enables the use of smaller trees harvested from second-growth forests and plantations rather than relying on old-growth forests. Glulam can also be manufactured in a variety of shapes, so it offers architects artistic freedom without sacrificing structural requirements. Versatility - Because the size and shape of glulam members can be so variable, they are able to be used as both beams and columns. Strength and stiffness - Glulam has a higher strength to weight ratio compared to both concrete and steel. Glulam also reduces the impact defects in the wood have on the strength of the member making it stronger than sawn lumber as well. Glulam has also been proven to have a higher resistance to lateral-torsional buckling than steel. Environmentally friendly - Glulam has much lower embodied energy than reinforced concrete and steel because the laminating process allows the timber to be used for much longer spans, heavier loads, and more complex shapes than reinforced concrete or steel. The embodied energy to produce it is one sixth of that of a comparable strength of steel. Also, as glulam is a wood product, it naturally sequesters carbon, keeping it from being released into the atmosphere. As long as the wood used to manufacture the glulam members comes from a sustainably managed forest, glulam is a renewable resource. Fire safety - While glulam is inherently flammable because it is made of wood, if it catches on fire a char layer forms that protects the interior of the member and thus maintains the strength of the member for some time. Disadvantages As with any system, there are some drawbacks to using glulam: Material cost - Glulam is generally noted to be more costly than concrete at high axial loads, though this can depend on location and its abundance of either material.