Roof Trusses Explained: Types, Benefits & Installation

You may not have known that roof trusses can cut the framing expenses of your roof by 40 percent and provide incomparable roof strength. As a solution for modern roofing, prefabricated trusses are taking the construction industry by storm as they are efficient and flexible. This guide explains roof trusses, their benefits, installation, and trends to help you choose the best system for your project.

The Definition of Roof Trusses

Roof trusses are pre-designed, triangular structures made of wood or steel that effectively support roofs. They are made of 

• top chords (rafters)
• bottom chords (ceiling joists)
• webs (internal supports) 

Which distributes the roof’s weight against exterior walls, obviating the necessity of having interior walls bear the load. This qualifies them as part of open floor plans and affordable construction.

Roof Trusses versus Traditional Rafters

Feature	Trusses	Rafters
Cost	30–50% cheaper	More expensive
Installation	Faster (prefab)	Slower (on-site cutting)
Design Flexibility	Limited (pre-engineered)	Highly customizable
Span Capability	Up to 60′	Typically 20–30′
Attic Space	Restricted by webs	Open space

Common Roof Truss Types

1. King Post Truss:
   Simple triangle with a central post, ideal for small spans (16–26′).
2. Queen Post Truss:
   Two vertical posts for medium spans (26–40′).
3. Fink (W) Truss:
   Most common, efficient for 20–60′ residential spans.
4. Scissor Truss:
   Creates vaulted ceilings, perfect for living spaces.
5. Attic Truss:
   Designed for storage or loft space with a higher bottom chord.
6. Gambrel Truss:
   Barn-style, maximizes upper floor space.
7. Mono Truss:
   Single-slope for sheds or lean-tos.
8. Parallel Chord Truss:
   Flat roof or floor applications.

Benefits of Roof Trusses

• Cost-Effective:
  30–50% less labor, minimal material waste.
• Structural Strength:
  Engineered for precise load distribution, supporting spans up to 60′.
• Construction Speed:
  Prefabricated trusses install in 1 to 2 days.
• Versatile Designs:
  Accommodate complex roof shapes like hips or gables.

Potential Drawbacks

• Limited Attic Space:
  Webs restrict usable areas unless using attic trusses.
• Fixed Designs:
  Pre-engineered, requiring exact specs upfront.
• Transport:
  Large trusses need specialized delivery.

Roof Truss Installation Process

1. Design Phase:
   Engineers use CAD to calculate loads (1–2 weeks).
2. Manufacturing:
   Custom-made parts using metal plate connectors.
3. Delivery & Setup:
   Trusses are hoisted into position by cranes.
4. Installation:
   Permanent sheathing.

Check out roof installation services here!

Maintenance & Longevity

• Lifespan:
  Age of wood (50+); age of steel (100+).
• Issues:
  Damage due to moisture (wood), loose connectors.
• Prevention:
  Be sure to ventilate attics and check after storms.

Check out fascia installation services here!

Are Trusses the Right Choice?

• Select Trusses When:
  You are constructing new, and you want cost/time savings with no requirement for open attic area.
• Should You Choose Rafters if:
  You are remodeling, require cathedral ceilings, or attic storage is a priority.

Calculate the loads with a structural engineer and get quotes on truss manufacturing. Check local building codes regarding roof framing. For extra help, get in touch with A2ZRoofing!