How Much The Flat Roof Thickness

Tpo is a type of roofing membrane that can come in a variety of thicknesses.

How much the flat roof thickness.

A built up roof for example will typically include the built up membrane itself with or without gravel as well as some kind of insulation and cover board which will vary in thickness from roof to roof. Flat roofs come in many shapes and sizes which include parapet roofs roof decks and green roofs to name just a few of the options available. Most flat roofs are typically not as long lasting or durable as sloped ones because the latter shed snow and rain a lot quicker. For example one company might sell a product as being 24 gauge but in reality the thickness of the metal could vary from 0 018 to 0 0335 based upon exactly how that company looks at things and how big of a tolerance they allow for.

A low slope roof is anything under 2 inches of fall per foot. Sheathing should be a minimum of 19 32 inch thick. The most common thickness is probably 60 mils. So a 45 mil roofing membrane is actually 0 045 inches thick.

Built up roofs or burs also called a tar and gravel roof is a well established and popular style of flat roof that is made up of alternating layers of roofing felt or fiberglass and asphalt that is applied with heat which combine to make a long lasting sturdy roofing system. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. I think it has to be 140mm but the quotes so far have been for 90 70 or 50 mm. Low slope or flat roofs are another story.

Roof sheathing standard roof sheathing which consists of 4 by 8 sheets of plywood or oriented strand board or osb is 1 2 inch thick and attaches directly to the roof rafters or the roof trusses. In general a roof truss manufactured from 2 by 4 lumber will support as much roof load as a 2 by 6 or 2 by 8 rafter. Ultimately a flat roof should play a part in a total architectural composition and has the ability to enhance the aesthetic and practical outcomes of a home. The problem with metal roofing gauge is that there is a wide range of tolerances.

However over the last few decades new and advanced materials have been developed. Well known midcentury real estate developer joseph eichler built many low slope or flat roofed homes in marin and the bay area. A classic flat roof is either almost completely level or has a very slight pitch of 3 in 12 inches or less. A mil is a unit of measure where 1 mil is equal to 0 001 inches.

Whereas a 60 mil membrane is 0 06 inches thick and so on. Modern for their time they do present a bit of a challenge when they need to be re roofed.