Final answer:
The two primary disadvantages of flat sawing boards are increased wood waste due to inefficiency in cutting, and the propensity for warping and cupping as the wood dries.
Step-by-step explanation:
The proces of flat sawing boards involves cutting lumber along the grain without adjusting the log's orientation, which can lead to two primary disadvantages.
One significant downside of flat sawing is the higher likelihood of producing wood waste. Due to the method's lack of orientation adjustment, more wood may be lost as sawdust or left in an unusable form. This inefficiency not only means that more logs are required to produce the same amount of usable lumber but also contributes to higher production costs and environmental concerns.
Another drawback is the increased potential for warping and cupping in flat-sawn lumber. The uneven distribution of growth rings in the boards, which is characteristic of this sawing technique, can cause the wood to deform as it dries and ages. This can lead to additional costs for manufacturers and end-users, who may need to replace or repair the warped materials, and proves to be a disadvantage in applications where structural integrity is paramount.