Dense lath and plaster offer insulation, fire protection, soundproofing, and other benefits. Lath and plaster walls offered some insulation, allowing dwellings to keep warmer in the winter and cooler in the summer. The thick coating of plaster muted noise transmission from one room to the next due to its density. The finish coat of plaster provides a smooth surface that resists stains and scratches. Plaster is used to cover large areas with few details such as ceilings or floors. It's also used where fine detail is desired, but space is limited. When applied properly, plaster is a durable, easy-to-clean surface ideal for home decoration and protection from environmental factors such as heat, cold, smoke, and moisture. The type of material used to create the plaster determines how it will react to these conditions. For example, drywall has a paper-based backing that is sensitive to heat; polystyrene has no fiberglass, so it's not recommended for places where there is a risk of fire Polyurethane (PU) foam is an insulation material that can be used instead of loose fill insulation. PU foam comes in several types including rigid, semi-rigid, and flexible. It's typically used in roofing applications because it's light weight and adds loft to the structure while reducing overall weight per square foot.