Glulam (Glue-Laminated) beams should not be ____________ or ____________ unless they were designed to be.

Glulam beams, or glue-laminated beams, are engineered wood products made from layers of lumber bonded together with adhesives. The strength and integrity of these beams depend significantly on their structural design. When considering modifications to such beams, it’s essential to adhere to the original design specifications.

Notching or drilling glulam beams can significantly alter their structural performance. These modifications can reduce the beam's load-bearing capacity and compromise the overall safety of the structure. Unless a beam is specifically engineered to handle notches or drilled holes, doing so can lead to failures or structural issues. This is why it is critically important that any such alterations only be performed if the beam has been designed for them.

In contrast, while cutting, sanding, painting, or laminating are important considerations in construction, the question specifically addresses modifications that could impact the engineering integrity of the glulam. Thus, notching and drilling are highlighted as inappropriate unless proper plans have been developed to accommodate these changes. This ensures that any alterations do not undermine the beam's intended performance.