What are the characteristics of sheet metal flashings and membrane flashings?

1) Sheet metal flashings are stiff, rugged, and relatively attractive while membrane flashings are flexible.
2) Sheet metal flashings are flexible while membrane flashings are stiff, rugged, and relatively attractive.
3) Sheet metal flashings are stiff, rugged, and relatively attractive while membrane flashings are stiff and inflexible.
4) Sheet metal flashings are flexible while membrane flashings are stiff and inflexible.

Sheet metal flashings are stiff, rugged, and relatively attractive, while membrane flashings are known for their flexibility, allowing them to create a tight seal around irregularity on surfaces.

Explanation:

The characteristics of sheet metal flashings and membrane flashings differ significantly due to the materials used and their respective properties. Sheet metal flashings are known for being stiff, rugged, and relatively attractive due to the inherent properties of metals which tend to be shiny, ductile, and malleable. Most metals are solids at room temperature and have high melting and boiling points, contributing to the durability and rigidity of sheet metal flashings.

In contrast, membrane flashings are typically more flexible. They are made from materials that can conform to irregular shapes and surfaces, which is important for creating a tight seal around the edges and corners of roofs and other surfaces to prevent water penetration. Unlike sheet metal, membrane materials can be stretched or flexed without breaking, adapting to movement or expansion within the structure.