Roof decks are designed to be the foundation of a roof. Roof decks are designed to support the roof system from the bottom upward. Deck material is a structural component that supports the waterproofing and insulation layers.
Roof decks must accommodate the movement of buildings, and the type of roof deck determines how the system components such as vapor retarder, insulation, and membrane are attached.
What Are the Most Common Types of Commercial Roofing Decking?
This article will discuss the types of decking that are used on commercial low-slope or flat roofs, such as those found in hotels, schools or warehouses. Ask yourself two questions before you begin:
1) Are you planning a membrane tear off, a complete reroof, or a new construction?
2) Do your roofs have any special features, like rooftop HVAC equipment, to take into consideration?
Roof deck materials should be chosen based on the weight of the roof system, which includes any snow accumulation or vegetative roof systems.
The same issues apply to membrane tear-offs as well as reroofing projects. It may be impossible to obtain critical information regarding the history of the roof or building depending on its age. Preparing the roof deck is the first step to installing any new roofing component. Roof decks perform several important functions including structural support and dimensional stability. They also provide fire resistance. Roof deck requirements are determined by the architect or specifier for each project.
Before Applying the Roofing System
The roof deck should be visually checked. Any defects found must be immediately reported to the general contractor or project superintendent. Roof installation should not begin until all problems have been addressed.
The roof deck should be constructed in new construction based on factors such as weight, equipment installed, foot traffic, and snow load. The roofing contractor is responsible for ensuring that:
- Roof decks are properly secured to supporting structures.
- Before roof system installation, the roof deck surface must be clean, dry and smooth. It should not have any depressions, waves or projections.
- Before installing the roof system, make sure that all equipment curbs and nailing strips are installed and secure.
Design Considerations
Roof decks should have a slope of at least 1:50 (or 1/4 inch per 12 inches). 1 A roof deck with the ideal characteristics has:
- This product provides a dry, clean and even surface that is suitable for cold-process applications, nailing or mopping.
- It does not allow moisture to enter the roof system.
- The required strength is met by the applicable building codes.
- Can resist dimensional changes.
- Fire, rot and decay resistant.
- Can support structural loads specified.
- It resists damage caused by handling, transit, installations, and foot traffic.
Roof decks should be checked to make sure that all decking is completed. After the inspection, any incomplete or incorrectly installed details in the deck will be repaired or completed satisfactorily. The roof application will then begin.
Questions that roofing contractors need to ask themselves include:
- Can the deck support a heavier roof system, for example replacing a built up roof membrane (4-10 psf), with a ballasted one-ply (10-20 psf).
- Will the deck be able to resist a pullout if mechanical fasteners are used to attach insulation, or a single-ply Membrane to the deck? For some single-ply membrane systems, a steel deck with a higher strength (80 ksi rather than 33 ksi) is required to meet wind design criteria.
- Will clearance for access to doors, windows, or equipment hatches be compromised if the existing roof membrane is removed to the deck and tapered insulation, or a sloped-fill, is installed to resolve ponding issues?
What Are the Most Common Types of Commercial Roofing Decking?
Roof decks are available in a variety of styles and materials.
- Planks, plywood or oriented-strand board (OSB) are all examples of wood-sawed lumber.
- Steel – cold-rolled corrugated.
- Precast structural concrete or concrete poured on site.
- Lightweight insulating concrete.
- Precast or poured gypsum.
- Insulating fill Thermoset.
- Composite decking materials
This post was written by professionals at Commercial Roof Services. Commercial Roof Services takes immense pride in being a leading commercial and industrial roofing company dedicated to providing top-tier roofing solutions for businesses and industries of all sizes. With a proven track record and a team of highly skilled professionals, CRS has become a go-to choice for clients seeking unmatched roofing services.