Choosing the best floor grate is largely a matter of selecting the right grate for a specific application, making sure that the grate is of high quality, and ensuring that its appearance is appropriate for its setting. Floor grates are used both for covering air vents and for screening over floor drains, especially in basements or near pools. Grates come in a variety of different materials and finishes, and when possible, more durable and corrosion-resistant grates should be chosen, especially for drains. Grates located in visible spaces should match the general décor of the areas in which they are situated, which may involve matching patterns in other grates or fixtures.
Grates are usually closely-matched to the size of the vents or drains that they cover. A modern floor grate will typically be built in a standard size, but older grates may not conform perfectly to contemporary standards, and some custom grates may also not be of typical sizes. When shopping for a floor grate, it is important to choose one that is of an appropriate size, as grates that do not fit properly may not be safe, and may also rattle or experience other problems.
Floor grates designed to cover air vents are often made of durable plastics. These grates are inexpensive and entirely corrosion-resistant but may not be as durable as metal grates. Grates made of metal are typically more expensive but are available in a wider variety of colors and styles and are generally treated to resist corrosion.
A floor grate designed to cover a drain will often, but not always, be made of materials that resist rust. Some grates, such as those found in many residential basement drains, are made of iron. This is because they can be made very inexpensively and because a moderate amount of rust is acceptable in such applications.
Floor grates covering larger trench drains can be made from many different materials. Durable plastics are resistant to corrosion and many chemicals but weaker than metal. Stainless steel can hold a great deal of weight but is more expensive. Aluminum does not rust but is moderately expensive and not as strong as steel. A floor grate should be strong enough to hold any traffic, foot or vehicle, which will pass over it, and should have any chemical resistance properties needed for the environment where it will be installed.
In some cases, the appearance of a floor grate is of primary importance. Many older homes used elegant wrought iron grates to cover floor vents. When working to restore or simulate this older style of design, appropriate floor grates should be chosen. Architectural salvage stores can often provide vintage floor grates. If such grates are not available, reproductions might serve as well. In any case, all the floor grates in a particular space should generally match one another.