Timber vs Steel Trusses: Which is the Best Framing Material for Your Residential Roof?

The roof frame is the foundation of your roof. It provides the structure onto which the covering sits. A quality framing material delivers the strength and stability required to increase the roof's lifespan and performance. Timber and steel trusses are popular roof framing materials today. However, they have significant differences that you should explore in detail before settling on the right option. With this in mind, here are a few factors to help you choose between timber and steel trusses for your roofing.

Longevity and performance

Both timber and steel trusses are incredibly durable. A well-designed timber frame can maintain the structural integrity of your roof for decades. However, timber is a natural material, which makes it susceptible to the elements. When exposed to moisture, it can rot or warp and undermine the structural integrity of the entire roof. This risk is usually inherent in leak-prone roofs, which have no underlayment.

Conversely, steel holds up excellently to the elements. It does not warp, rot or get damaged by insects. These elements, combined with the structural strength of steel, deliver a durable roofing structure. The only downside is that steel can be prone to corrosion, especially after long-term exposure to moisture. Thus, a leaking roof can prove problematic to steel trusses. 

Resistance to fire

If you live in a fire-prone area, you need to explore fire-rated building materials. Most people opt for metal and asphalt roofs because they have excellent fire resistance properties. However, if your framing is not fire rated, it can catch and spread fire, even if the roof covering is fire resistant. 

Timber is a combustible material; however, it chars on the surface while protecting the inner core from burning. You can fireproof timber by treating it or applying fire-resistant paint. Steel is resistant to fire, meaning it does not combust if there is a fire. Fireproof steel can withstand extremely high temperatures, making it a better material for fire-prone areas than timber.

Installation costs and complexities

Timber trusses are cheaper than steel trusses, but they do not last as long as steel. Additional treatments such as chemical treatments and fireproofing may increase the cost of timber trusses. Also, wood is heavy; therefore, the installation process may be slow, leading to increased billable hours.

Steel is a light material that is easy to handle. However, installing steel framing requires a lot of expertise. The material is still relatively new in the residential construction arena; thus, your roofer must follow manufacturer instructions to avoid underperformance. All this can add up to huge installation costs.

Timber trusses are widely used for residential roofing. However, steel, which is common in commercial construction, is gaining popularity among home builders due to its strength, durability and fire-resistant properties. If you need professional input regarding the two materials, consult your roofing contractor.