Loadmaster Structural Composite Roof Decks

Loadmaster roof decks are structural composite roof decks — assemblies of components that are mechanically joined to act as a single, unified structural unit. This composite construction delivers strength that far exceeds what each individual component could provide on its own.

That added strength translates directly into real-world building performance. Loadmaster composite roof decks provide:

• Gravity load resistance – supporting the weight of the roof and everything on it

• Wind uplift resistance – keeping the roof secured during high-wind events

• Diaphragm shear resistance – distributing lateral forces across the structure

Together, these properties stabilize the entire building under both wind and seismic conditions, making Loadmaster roof decks a critical part of a safe, code-compliant structural system.

A Loadmaster Roof Deck requires a Loadmaster-specified retrofit assembly, substituting materials from other manufacturers voids the engineered system design and puts your project out of IBC compliance.

Please see our »retrofitting Loadmaster page« for more information.

The Loadmaster Roof Deck Retrofit System

The Loadmaster Renewal System is a complete assembly of engineered components designed, tested, and proven to restore structural composite properties to aging roof decks — before, during, or after the reroofing process.

Over time, roof decks can lose the composite action that makes them structurally sound. This system brings that performance back. It is compatible with:

• Loadmaster structural composite roof decks

• Lightweight Insulating Concrete (LWIC) roof decks

• Poured Gypsum roof decks

The system also addresses a common challenge in modern reroofing projects: LWIC roof decks that need additional insulation to meet current energy code requirements — delivering both structural renewal and energy code compliance in a single solution.

How Loadmaster Roof Decks Are Renewed During Reroofing

Reroofing typically becomes necessary when two layers of roof covering have been installed over the deck and require replacement. However, removing those layers causes damage to the Duraflex Mineral Board — the top component of the assembly — and weakens its attachment to the steel sections below. This damage significantly reduces the structural composite strength of the entire roof deck.

The Loadmaster renewal process restores that strength in three straightforward steps:

1. Optional new insulation – An additional insulation layer may be installed to meet current energy code requirements or improve thermal performance

2. New Duraflex Mineral Board – A new layer is installed over the new insulation or existing Duraflex using an engineered screw attachment pattern specifically designed to reinstate composite action

3. New roof covering – Once composite strength is restored, the new roof covering is installed over the new Duraflex Mineral Board

This process ensures the roof deck performs as a true structural composite system — not just a weatherproofing layer — once reroofing is complete.

Why Choose a Loadmaster Roof Deck System?

If you want a roof deck and roof covering that deliver decades of trouble-free performance, Loadmaster is the clear choice. Every Loadmaster roof deck system is engineered to protect your building, extend the life of your roof covering, and give you confidence that your investment is built to last.

What's included with every Loadmaster system:

• Free design and engineering – Expert support from the start, at no additional cost

• Competitive pricing – High-performance roofing that fits your budget

• Installation by trained and licensed dealers – Every installation is performed by certified professionals

• Outstanding substrate support – A stable, stress-free surface that bonds with and extends the life of your roof covering

• Guaranteed compatibility – Your roof covering is guaranteed to work with the Loadmaster system

• Guaranteed structural performance – Engineered and tested to meet published structural ratings

• Lifetime building performance – Designed to last the life of the building, not just the roof covering

• Delayed recover costs – A stress-free substrate extends roof covering life, pushing recover costs years — even decades — into the future

• Superior wind blow-off protection – Exceptional uplift resistance keeps your roof secured in high-wind events

• Full IBC code compliance – Meets all International Building Code requirements

The bottom line: Loadmaster roof decks don't just support your roof — they protect your building, reduce long-term costs, and deliver the kind of trouble-free service you can count on for the life of your structure

Free Design, Engineering, and Cost Analysis for Every Project

With over 5,000 available assemblies — and solutions for both new construction and retrofit projects — Loadmaster tailors every system to the specific needs of your building. There is no one-size-fits-all approach here.

The process is simple:

1. We gather your building's requirements – Structural loads, deck type, energy code requirements, and project scope are all taken into account

2. Loadmaster's technical team designs and engineers your system – A custom solution is developed at no cost to the building owner

3. Your local Loadmaster dealer prepares a cost analysis – Accurate, project-specific pricing based on the engineered design

Whether you're working on a new build or a reroofing project, Loadmaster's technical department handles the complex design and engineering work so you don't have to — and at no charge.

The Loadmaster Terminator System: Permanent Steel Termination and Transition Assemblies

The Loadmaster Terminator System is a fully engineered assembly of fabricated steel components that form structural composite units — purpose-built to handle all roof deck termination and transition needs.

Traditional roofing relied on wood blocking and similar materials fastened to steel members to manage these transitions. Wood blocking is unstable, subject to rot and deterioration, and simply not up to the structural demands of a high-performance roof deck system. The Terminator System eliminates these weaknesses entirely.

What sets the Terminator System apart:

• All-steel construction – Permanent, galvanized steel shapes that won't rot, warp, or degrade over time

• Engineered fit – Components are designed and engineered to fit together precisely, meeting termination and transition requirements more effectively than legacy methods

• Structural composite performance – Functions as part of the overall composite roof deck system, not just an accessory

• Long-term reliability – A permanent solution that performs for the life of the building

For project-specific guidance, contact Loadmaster's Technical Department for a free design and engineering consultation.

Nailable Loadmaster Roof Decks: Why Loadmaster Duraflex Mineral Board Outperforms Wood Sheathing

Nailable Loadmaster roof decks replace traditional organic wood sheathing with inorganic mineral boards — and the difference in long-term performance is significant.

The problem with wood sheathing:

Wood sheathing trapped inside a roof deck assembly is cut off from the atmosphere. Without access to ambient moisture, heat from the roof covering drives moisture out of the wood — and it can't be replaced. With a natural moisture content of approximately 19%, wood sheathing will inevitably:

• Shrink as moisture is lost

• Split under the stress of repeated thermal cycling

• Curl as the material becomes unstable

This movement doesn't stay contained — it transfers directly to the shingle roof above, causing disturbance, premature wear, and shortened roof covering life.

The Loadmaster mineral board advantage:

Loadmaster's mineral boards are made entirely from inorganic minerals, making them completely unaffected by heat or moisture loss. They provide:

• A stable, permanent sheathing surface that won't shrink, split, or curl

• Fireproof construction that enhances the overall fire resistance of the roof assembly

• Lifetime building performance — designed to last as long as the structure itself

The real-world results speak for themselves: shingles installed over Loadmaster mineral board consistently last significantly longer than those installed over wood sheathing.

Loadmaster Roof Decks for Curved Applications

Not only can Loadmaster roof decks be used for curved applications — they are ideally suited for them.

The components of a Loadmaster assembly are designed to flex and curve naturally, conforming to a wide range of architectural shapes without compromising structural integrity. The tongue and groove side connections of the mineral boards are secured using the same engineered anchorage that creates the structural composite action throughout the system. This means:

• No seams or ridges – Components connect firmly at both ends and sides, eliminating the gaps and raised edges that can occur with less flexible systems

• A consistently smooth surface – The result is a seamless, uniform substrate across the entire curved area

• Full structural composite performance – Curved installations retain all the strength and stability of a standard Loadmaster assembly

Whether the design calls for a gentle arc or a more pronounced curve, Loadmaster delivers a clean, structurally sound surface that supports the roof covering and the architectural vision equally well.

Loadmaster Fire Resistance Ratings: UL Listed for 1, 2, and 3-Hour Performance

Loadmaster roof decks are extensively tested and certified for fire resistance, with over 50 listings from Underwriters Laboratories, Inc. (UL) covering:

• 1-hour fire resistance ratings

• 2-hour fire resistance ratings

• 3-hour fire resistance ratings

This broad range of UL listings gives architects, engineers, and building owners the flexibility to select a Loadmaster assembly that meets the specific fire resistance requirements of virtually any project — from standard commercial buildings to the most demanding high-occupancy or high-risk occupancies.

For project-specific fire resistance designs, consult the Loadmaster Technical Department or reference the Underwriters Laboratories, Inc. Fire Resistance Directory.

Loadmaster Roof Deck Warranties: 10 to 30 Years of Guaranteed Performance

Every Loadmaster installation is eligible for a warranty — giving building owners and specifiers confidence that their investment is protected for the long term.

Warranty coverage options:

• Duration: 10 to 30 years, aligned with the roof covering's warranty against leakage

• Structural performance: The roof deck's engineered structural integrity is guaranteed

• Roof covering support: The deck's suitability to sustain and support the roof covering is covered

• Wind resistance: Protection against wind uplift failure is included in every warranty

Loadmaster warranties are comprehensive by design — covering not just the deck itself, but its ability to perform as a complete, integrated roofing system.

For full warranty terms and project-specific details, contact the Loadmaster Technical Department for a free consultation.

Loadmaster Roof Decks for Slate and Tile: A Permanent Solution for Permanent Roof Coverings

Slate and tile are among the most durable and long-lasting roof coverings available — but their performance is only as good as the deck beneath them. Both materials demand a permanent, stable substrate. Nailable Loadmaster roof decks deliver exactly that.

The problem with wood sheathing under slate and tile:

Wood sheathing trapped inside a roof deck assembly is cut off from the atmosphere. Heat from the roof covering drives moisture out of the wood — and with no access to ambient moisture, it cannot be replaced. With a natural moisture content of approximately 19%, wood sheathing will inevitably:

• Shrink as moisture is lost

• Split under repeated thermal cycling

• Curl as the material becomes permanently unstable

This movement transfers directly to the slate or tile above — disturbing the roof covering, breaking the installation, and causing premature failures in what should be a lifetime roof.

Why Loadmaster mineral boards are the right choice:

Loadmaster replaces temporary, unstable organic wood sheathing with permanent, inorganic mineral boards that are completely unaffected by heat or moisture loss. The result is:

• A stable, permanent substrate that won't shrink, split, or curl — ever

• Fireproof construction that enhances the overall fire resistance of the assembly

• True lifetime performance — mineral boards are designed to last as long as the building itself

The real-world results are clear: both slate and tile installed over Loadmaster consistently deliver decades of trouble-free service — significantly outlasting installations over wood sheathing.