Why is my metal roof making popping noises?

Popping, ticking and banging from a metal roof almost always come from the metal moving with temperature. Steel grows as the sun heats it and shrinks as it cools, and when something stops the panels from sliding freely, the stress builds up and releases with a sound. Most of the time it is a nuisance, not damage. Below are the usual causes, how to tell them apart from the ground, and when the noise is a reason to call a roofer.

The usual cause: thermal movement

Metal Sales, a panel maker, puts it this way: Steel roofing panels are subject to dimensional changes after installation due to exposure to varying temperatures.^[1] It adds: "The greatest influence is solar energy."^[1] That is why the noise tends to follow the sun. Many owners hear it in the morning as the roof warms, when a cloud passes on a hot day, and again in the evening as it cools.

Movement itself is expected. Noise comes when the movement is held back. Sheffield Metals, a metal supplier, says: When you restrict the expansion and contraction a panel needs, you can run into a noise issue,^[3] along with other problems.

Why some metal roofs are louder than others

Standing seam roofs. These are designed to move. On Metal Sales' standing seam system, floating clips let the panels move independently of the roof structure underneath,^[1] and when a panel run is longer than the clips can accommodate, expansion joints must be designed into the roof.^[1] If fixed clips, tight trim or a bead of sealant pin the panels where they should slide, the roof can pop.

Screw-down (exposed-fastener) roofs. Here every screw holds the panel to the framing. Metal Sales warns that thermal movement can loosen the screws' grip in the framing, make fasteners back out, break fasteners and elongate the holes in the panels.^[2] Its guide says thermal movement should be considered on panels longer than 20 feet, and panel runs longer than 40 feet generally need some way to accommodate it.^[2] Long, single-piece panels on a barn, porch or house are the ones most likely to tick and pop.

Loose fasteners. A panel that can rattle against a loose screw makes more noise in wind and as it moves. Sheffield notes that exposed fastener roofs should have their fasteners checked every year because they can back out from expansion and contraction over time.^[5]

Wavy panels and oil canning

Oil canning makes a metal panel look wavy or distorted.^[4] McElroy Metal lists common causes including over-driven fasteners, deviations in the roof structure, movement of the structure, and temperature differences along the roof, usually when one part is in sun and another in shade.^[4] McElroy calls it in almost all cases an aesthetic issue that does not affect performance.^[4] It matters here because it shares a root cause with noise: Sheffield lists restricted thermal movement as a cause of both noise and oil canning.^[3] If your noisy roof also has rippled, shiny patches that shift with the light, the two are likely connected.

Rain noise is a different problem

A drumming sound in rain or hail is not thermal movement. Sheffield explains that rain and hail are more noticeable on metal installed directly over open framing, because there is no deck, sheathing or insulation to muffle the sound.^[3] On a house it is different: McElroy says rain on a residential metal roof over decking, underlayment, attic insulation and a ceiling sounds about the same as rain on any other roof.^[6]

If you are adding insulation to quiet a garage, shop or porch roof, Sheffield suggests you ask the installer to make sure the insulation allows for adequate thermal movement.^[3] Otherwise you can trade drumming for popping.

What you can note without going on the roof

A roofer will find the cause faster with a few observations from you:

• When it happens. Morning warm-up, midday sun and clouds, evening cool-down, wind, or rain.
• Where it comes from. One slope, a long run of panel, near a chimney, wall or skylight, or over a porch.
• What it looks like from the ground. Binoculars help: look for screws standing proud, lifted panel edges, wavy panels or loose trim.
• What is inside. In the attic, look for daylight at screw holes and for wet spots. Drips that appear on cool, clear mornings rather than in rain point to condensation: The underside of a metal roof can dip below the dew point on clear, cool nights, even in summer.^[7] See why a metal roof leaks at the screws for how to tell the two apart.

Short videos with sound, taken at the time of day the noise happens, are worth more than a description.

When to call a licensed pro

Call a roofer when the noise is new, getting louder or more frequent, follows a storm, or comes with loose screws, lifted panels, waviness that is spreading, or water inside. Those signs point to fasteners letting go or panels working loose, which can lead to leaks or wind damage.

Do not go up to look. Metal Sales' own guide warns installers: "Never walk on frosty, icy, or wet panels."^[1] Re-securing panels, replacing fasteners or freeing trim is roof work. In Virginia, roofing contracting is the licensed specialty for repairing the materials that form a watertight, weather-resistant roof surface.^[9] Check a roofer using DPOR's License Lookup or by calling (804) 367-8511,^[10] and, if the roof is young, call the original installer first, since a workmanship warranty covers the installer's own work, such as clip, fastener and trim installation.^[8]

For related problems, see how leaking screws on a metal roof are fixed and whether a metal roof needs maintenance, or browse more exterior answers and metal roof repair. Loclis lists licensed businesses from Virginia's DPOR register, including exterior contractors in Blacksburg.

Describe the noise and add your videos, and licensed local roofers send quotes or offer an estimate visit.