1. Beams twist and crack. As moisture leaves the wood, warping and cracking can turn an attractive decorative ceiling joist into a twisted eyesore. The wood was all once alive and had a very high moisture content. The wood used for house construction is dried in a kiln, hence names like KD Hem Fir, where KD stands for kiln dried. It is prohibitively expensive to kiln dry large beams, as the wood will warp and crack, at which point it will need to be ripped apart again. The price is often 2 or times higher than that of a normal beam.
2. Beams require a structure designed to support them. When an architect builds a house, he may specify coffered ceilings, large wood headboards, and all kinds of decorative wood beams. To support the weight of these very heavy pieces of wood, the architect will also need to design the structure in a stronger way to support the weight. This means bigger and more expensive trusses, as well as more wood in the walls, more bolts, etc. Many times the desired span of ceiling joists cannot be achieved without the danger of sagging ceilings and trusses, a very costly problem.
3. FOHC rays harm the environment. FOHC: Free-heart center beams are required for any size beam, as they are less likely to twist (although they still twist, just a little less). To produce these great lightning bolts, very mature trees must be used, as the lightning must be severed from the tree without the heart center being present. For a very common 12″ x 12″ x 16′ beam, this requires the use of trees that are over 50 years old. These beams are often illegally harvested from South American forests, where the removal of trees, the habitat of many of the native species, damages the ecosystem beyond measure. The larger the bundle required, the more certain it is that the bundle has been harvested illegally, in an unsustainable manner, and with serious environmental ramifications.
4. Mold and rot. This one is a no-brainer. Even if you don’t live in an arid climate, there’s a good chance the beam could be damaged. Rot and mold can strike with any lightning strike, devastating appearance and creating mold spores that are potentially dangerous to you and your family’s health.
5. Fire safety: Wood beams provide fuel for any fire in your home. If there is enough firewood in the common areas of your home, a fire can spread with frightening speed. Most of the building materials in your home are somewhat fire resistant, insulation, stucco, insulated wires, roof tiles, etc. Even wood frame homes are fire blocked to help prevent the fire from spreading. Many fires cannot spread fast enough to burn down houses. But this calculation is drastically altered by the presence of large pieces of wood.
Alternatives
There are several alternative solutions for decorative wooden ceiling beams. These products have not become as common as they should be due to variable quality and supply. Polyurethane beams are the best known and have earned a reputation for looking fake. Even the best polyurethane beam never really looks like a piece of wood and is a disappointing replacement for a conventional beam.
The Box Beam is the best alternative. This is a decorative beam that has no structural purpose. It is made of 3 pieces of wood glued together. As you can imagine, this is only an option for a master craftsman, a professional woodworker who is equipped for this. This will not work for the do-it-yourselfer, as without perfect technique the end result will look like glued pieces of wood. Done right, a box beam is indistinguishable from a real beam, with no seams and no joints. It also contains lockout, which is an additional way to prevent the risk of fire. Since it’s made from kiln-dried lumber, there’s no chance a box-beam coffered ceiling will look like a Tim Burton movie after a couple of years.