June 15, 2020 in Blog

Thermal Expansion of Steel in Hot Climates Like Phoenix

Did you know that the dimensions of steel change constantly along with its surface temperature? The thermal expansion of steel makes it a bit of a shapeshifter in hot climates like Phoenix. If you’re building with steel, you will need to allow for some wiggle room. Steel expands when it’s hot and contracts when it’s cool—this is known as thermal movement. The steel experts at Arizona Iron Supply in Phoenix understand steel and how it is affected by our hot climate. We can outfit you with the right kind of steel for your next building project in Arizona.

How much does steel expand?

The thermal expansion coefficient of steel is 0.0000072 inches per degree Fahrenheit. This amount may seem fractional, but it adds up quickly. Thermal expansion has a linear effect on steel; expansion accumulates in proportion to unbroken length. The greater the length of your structural beams, roofing panels, or pipes, the greater the thermal expansion length will be.

Steel Roofing 

Galvanized steel, pre-finished steel, stainless steel are some of the most common materials used for sheet metal roofing. Thermal expansion depends on the surface temperature of the steel, not the ambient air temperature. It might be 100 degrees outside, but even though your steel roofing reflects sunlight, it could be much hotter. Steel that is exposed to the Arizona sun soaks up that solar energy and gets extremely hot. On long summer days, roof surface temperatures can easily surpass 150 degrees. Expansion between sheet metal panels could dislodge steel roofing from its supports unless builders allow for flexibility at the joints.

Steel Pipes

Steel pipes are used in construction for heating and cooling systems as well as plumbing. Depending on the size of the building, steel pipe networks can be hundreds of feet long. A 100-foot steel pipe will lengthen almost an entire inch with only a ten-degree change in temperature. In Arizona, the desert climate can cause temperatures to fluctuate twenty or even thirty degrees in one day. 

Hot days and cold nights mean that your steel pipes are constantly expanding and contracting. If steel pipes are not fitted properly, thermal expansion creates leaks and causes water damage. Excessive thermal expansion can even cause pipes to buckle and damage walls or floors. Using insulated steel pipes and fitting them with expansion joints will prevent leaks and structural damage.

Steel Beams

Following fire safety construction codes ensures the structural integrity of steel supports. Any fire safe building will be able to withstand the desert heat. Fire safety engineers must plan for the thermal expansion of steel under extreme conditions. Expansion of structural steel during a fire can displace masonry and concrete and collapse an entire building. At 1000ºF, a 100-foot length of steel will expand by 9.5 inches. As long as you ensure that your building is up to code, you should have no worries about the thermal expansion of structural steel in the Arizona climate.

Contact Us

Arizona Iron Supply offers an extensive array of steel sheet metal, rods, pipes, and fittings. Understanding the properties of different types of steel helps us find the best product for your needs. Our warehouses in Phoenix and Scottsdale can outfit you with the right steel parts to get the job done! Check out our inventory online, or call us at 1-800-528-9875 to learn more.


Photo by Dakota Roos on Unsplash