The leading safety hazards on construction sites include falls, being caught between objects, electrocutions, and being struck by objects. ... Areas where there is limited training include tasks in design for safety, safety inspection, and monitoring safety.

Excavation and trenching are among the most hazardous construction operations. OSHA defines an excavation as any man-made cut, cavity, trench, or depression in the earth's surface formed by earth removal.

The physical components of the envelope include the foundation, roof, walls, doors, windows, ceiling, and their related barriers and insulation.

The problem is that concrete is not waterproof, so a waterproof membrane is fitter over the concrete surface to seal it. The best way to seal it is a torch-on system (applied with a gas flame) and then an aluminum coating to protect it from the sun.

Most of the tiles will need to be cut to fit the perimeter of the room; starting in a corner allows you to begin the pattern with full tiles on a straight line and move evenly into the room.