Roof Noise Transmission and Structural Noises

Are Steel Metal Roofs noisier than other Roof types?

Steel metal roofs found in modern building installations are not noticeably noisier than other roof types. The choice of the type of metal roofing, roof decking, fastener method, roof insulation method and underlayment can all actually make the difference on steel metal roofing when it comes to noise transmission and reduction.

Here is a model for the proper installation of steel metal roofing. The roof framing support would comprise of I-joists and the roof cavity is fully insulated with blown-in foam. Seal gaps with expanding sealant products.

During a heavy rain downfall, one can observe from the space below the roof to hear only a much muted sound of rainfall on the roof surface. The sound level would not be far different from an asphalt-shingle roof of similar design and use.
Nevertheless, based on several experts and their field experience, it is clear that some metal roofs and some roofs covered with other materials can be very noisy.

There are also several buildings were serious occupants complain about roof noise levels observed at roofs of various designs and materials.

How is Roof Noise Transmitted into a Building?

Roof noises are transmitted into buildings by two methods regardless of their sources;

1. Airborne Sound is a sound wave that travels through air and moves between building areas through open doors, windows, stairwells and unsealed gaps.

2. Mechanically transmitted sound is a sound that moves through solid building components such as ceilings, floors, framing, and walls. These components carry sound from one area to another. The sound transmission is technically referred to as the IIC or the Impact Insulation Class sound transmission.

There are certain building configurations that may also transmit noises to its interior through its roof sheathing and building framing. Such structures include; metal roofed buildings, low slope or flat roof houses, occupied attics and occupied under-roof areas with cathedral ceilings.

But in buildings that are located under flight paths to airports, the demand for roof-transmitted sound reduction is mostly sought for.

Roof noises can actually be determined based on their obvious sources.

1. The roar and patter of falling rain or hail,
2. The popping and cracking noises due to thermal expansion and contraction of metal roofing, or roof structure
3. Transmitted noises from other external sources like low-flying aircraft, nearby trains, and vehicular traffic from a nearby highway.
4. Loud roof booming noises in cold climates due to a fracture caused by water freezing on a flat or low slope roof.
5. And such other noises attributed to other building components and near the roof installations such as antennas, cables, wires, signs and roof-mounted equipment.

Reducing noise transmission into your home interior can basically be done through proper installation of steel metal roofing systems and sufficient insulation to keep noise away. You can consult an expert in acoustics and strictly follow manufacturer standards in installing steel metal roofing. Roof noise transmission can be controlled, prevented and corrected.