When selecting a roofing material, most homeowners in the Fraser Valley, Lower Mainland, and throughout British Columbia consider factors like durability, cost, and appearance. However, an often-overlooked aspect is the noise produced by rain. Roofing materials can vary widely in how they absorb, reflect, or amplify sounds, particularly the sound of raindrops hitting the surface. While metal roofs are known for their strength and long lifespan, they are often associated with louder rain sounds compared to traditional materials like asphalt shingles, concrete tiles, or wood shakes.
But how loud are they really? And is there anything homeowners can do to reduce the noise caused by a metal roof during rainfall? In this article, we'll explore the factors that contribute to the sound of rain on metal roofing, as well as methods to mitigate it, particularly focusing on the role of insulation and building construction.
Metal roofs have become increasingly popular in regions like British Columbia, especially due to their ability to withstand heavy rain and extreme weather. However, their sound performance is a key consideration, especially in areas like the Fraser Valley, where rain is a frequent visitor throughout the year. When raindrops hit the smooth, hard surface of a metal roof, they tend to be reflected and amplified. The sound can be particularly noticeable during a heavy downpour, as the metal surface doesn't absorb the impact as softer materials would.
It’s important to note that the perceived sound of rain on a metal roof can vary significantly depending on several variables, and these variables make it difficult to pin down an exact decibel level. Many studies have been conducted to measure the dBa levels of different roofing materials, but in practice, the noise level inside a home depends on factors like roof pitch, deck construction, insulation, and the underlayment.
The pitch or angle of the roof plays a significant role in how much noise you will hear when it rains. A steeper roof pitch (common in the Fraser Valley to facilitate water drainage) will generally result in less noise than a low-pitched or flat roof. This is because, on a steeper roof, rain will glance off the surface at an angle, while on a low-pitched roof, raindrops will strike the surface more directly, increasing the intensity of the noise.
However, the difference between a steep and low pitch may not be drastic enough to drastically change the overall experience for most homeowners. In most cases, this is not a factor significant enough to warrant changes in building design specifically to reduce noise.
The construction of the roof deck has a notable impact on the amount of noise generated by rainfall. When a metal roof is installed over strapping (a series of narrow strips of wood or metal), the sound of raindrops is more likely to be amplified, as the space between the metal and the underlying deck allows for more echo. On the other hand, a plywood roof deck (or solid sheathing) can help to dampen the sound, as the wood absorbs some of the impact of the rain.
In general, a thicker, denser roof deck will offer a better sound barrier. This is why homes built with solid plywood decking may be less noisy during rainfall than those with strapping alone.
A metal roof in the Fraser Valley with strapping used as a roof deck and no membrane installed. This is a very common method on large barns and shops, but it can be very noisy in heavy downpours.
One of the most effective ways to reduce the sound of rain hitting a metal roof is by adding insulation. Thicker insulation in the attic space can significantly decrease the amount of noise that reaches the living areas of the home. Insulation not only acts as a thermal barrier, but it also helps to absorb sound. For maximum sound reduction, homeowners can opt for thicker insulation or soundproofing materials that are specifically designed to dampen noise.
In some cases, rigid insulation boards are installed over the roof deck, just below the roofing materials. This setup provides an additional layer of soundproofing, acting as a cushion that reduces the sound of rain.
Underlayment, which is installed between the roof deck and the metal roofing materials, can also help reduce noise. While most standard underlayments won’t significantly affect sound reduction, there are a few products specifically designed to dampen noise.
Both of these underlayment products can significantly reduce the noise produced by a metal roof, making them a good investment for homeowners concerned about sound.
Peel and Stick membrane and Drainage Mat under a metal roof in Horseshoe Bay
For homeowners in areas like British Columbia, where rain is a common part of life, it’s worth investing in a combination of insulation, underlayment, and construction techniques to reduce noise levels. Some additional strategies to consider include:
While metal roofs can produce more noise during rainfall compared to traditional roofing materials, the overall experience is highly dependent on several factors such as roof pitch, deck construction, insulation, and underlayment. Homeowners in the Fraser Valley, Lower Mainland, and other areas of British Columbia can take steps to mitigate noise, ensuring that their homes remain quiet and comfortable, even during heavy rain.
By investing in quality insulation, acoustic underlayment, and soundproofing construction techniques, homeowners can reduce the impact of rain noise on their living space. With the right combination of roofing material and building methods, a metal roof can provide the durability and protection needed, without disrupting the peace and quiet inside the home.
