Laminated wood offers several advantages over solid wood. Which of the following is NOT an advantage of laminated wood?
- AStructures can be designed with laminated wood based on the required strength and low-grade wood can be positioned accordingly.
- BIt can be used to fabricate large members that are impossible to be made from solid wood.
- CIndividual boards, which are used in laminated wood due to their relative thinness, can be properly dried without checking (cracking) and defects, such as knots, can be removed.
- DSince laminated wood is glued, wood of only large dimensions can be used, which increases the amount of waste.Correct
Solution
Concept
Laminated wood is made by gluing many thin, small boards, so small-size wood can be used and waste is reduced.
Step-by-step solution
1. Laminated wood (glulam) is made by gluing thin layers of wood together. 2. Option A is true: high-grade layers go in high-stress zones and low-grade layers in low-stress zones. 3. Option B is true: long and large members can be made beyond natural log size. 4. Option C is true: thin boards dry well without checking, and knots or defects can be cut out. 5. Option D is false: gluing allows small pieces to be used, which reduces waste. 6. So the statement that is NOT an advantage is (D).
Explanation
The main benefit of laminated wood is that small and thin pieces are glued into big members. So it does not need large-size wood and it reduces waste. Statement D says the opposite, so it is not an advantage.
Why the other options are wrong
A, B and C are all true advantages of laminated wood: grade placement as per stress, large member sizes, and better drying with defect removal.
Shortcut
Lamination means small pieces glued into a big member, so any option saying 'only large wood' or 'more waste' is wrong.
Common mistake
Reading the question as 'which is an advantage' and missing the word NOT.
Correct answer: D) Since laminated wood is glued, wood of only large dimensions can be used, which increases the amount of waste.