Metal roofs are popular due to their long life spans, good looks and ease of maintenance. However, in some cases, metal roofs can facilitate the transmission of annoying sounds. Below is more information on how you can identify unknown noises and prevent or correct metal roof noises:
Identifying unknown sources of roof noise
The source of metal roof noise isn't always easy to identify. Obvious sources of noise include rain and sleet, and falling tree nuts such as acorns. However, many other sounds are difficult to diagnose; home owners describe "booms", "screeches", "rattles" and other obnoxious, but vague, sounds, and their origin can be hard to pinpoint without investigation.
That's why it is important to systematically investigate unknown metal roof noises; below are a few questions you should answer when trying to determine where the noise arises:
- Does the roof noise occur only at certain times of day or night, or is the occurrence of the sound seem to be randomly distributed?
- Does the roof noise appear only when it is cold or hot, or is there no discernible temperature-related pattern?
- Are there any known wild animals in the area, such as squirrels or raccoons, that might be able to access your roof?
- Is there any history of roof damage or active or repaired leaks?
- Are there any structures attached to the roof, such as attic fans, vent stacks, antennas, satellite dishes, or other objects?
By answering the above questions, you can gather a few clues about what might be causing the trouble. As you think about your answers, consider the following possible sources of metal roof noise:
- Ice cracking – this is more likely to occur on flatter roofs in cold climates, though it can also happen if a leak allows water to accumulate in gaps beneath the metal. As accumulated water freezes on or underneath a roof, the expanding ice can fracture and create a loud popping or booming noise.
- Thermal expansion – various residential roofing materials expand and contract at different rates during periods of rising and falling temperatures. When these materials are connected together, the variance in expansion and contraction can cause shifting and slipping; this can lead to a variety of mysterious sounds that are difficult to pinpoint.
- Animals – in some cases, animals can cause metal roof noise. Depending on the species, animal activity is often clustered during the day or at night. Animal presence can be verified by the appearance of droppings, scratches and other signs of activity.
- Inadequately fastened objects – antennas, stacks and other roof-mounted structures can create noise if they aren't properly attached or sound-insulated. These types of sounds are more likely to appear during windy conditions as the objects shift or move.
What can be done about metal roof noise
Metal roof noise can be reduced by following a few guidelines for installation and soundproofing. Below are some strategies that can be employed to prevent or mitigate existing noises:
- Use foam insulating panels – foam panels will assist in reducing metal roof noises of most origins. These panels can be installed directly below metal roof sections. Just be sure to use appropriately-lengthened fasteners when attaching roof sections so the added depth of the foam panels is taken into consideration.
- Install plywood decking – the use of plywood decking will provide an economical, sound-absorbent medium for metal roofs. This can be incorporated with or without foam panels.
- Use filament-fiber underlayment – a "three-dimensional" filament-fiber underlayment can serve to absorb the movement of metal roofing and help dampen sound. The spongy material also helps reduce summer roof temperatures as a bonus and can aid moisture drainage.
- Correctly install the right fasteners in appropriate numbers – metal roof fasteners must be correctly installed to be as effective as possible. Loose fasteners or an insufficient number of fasteners can lead to the roof shifting and producing noise as a result.
- Insulate the attic interior – expanding foam insulation inserted into the space beneath the decking can help reduce sound transmission. In addition, blown insulation inside of attics can lessen the travel of sound waves through the air.
- Trap and remove animals – if you discover you have a nuisance animal problem, then you can trap and remove animals. Be sure to obtain assistance from your local extension agent or the appropriate state wildlife agency before trapping so you comply with state and federal laws.