Lightweight Insulating Concrete Roof Deck Installers (LWIC)

LWIC Brands We Install

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Elastizell logo
Aerix industries logo
Celcore inc logo

What is Lightweight Insulating Concrete (LWIC)?

Lightweight insulating concrete (LWIC) is a roofing system component that combines insulation, slope, and a durable substrate into a single monolithic assembly. The system is typically comprised of expanded polystyrene (EPS) insulation and lightweight insulating concrete, which is produced from a controlled mix of Portland cement, water, and pre-generated foam proportioned to meet a specified design mix.

The EPS insulation is installed into a slurry coat of LWIC over the structural deck and then encapsulated with a top pour of LWIC. Once cured, the assembly provides slope, thermal performance, and a durable roofing substrate within a single integrated system.

This type of system provides significant flexibility in creating slope and drainage, particularly in challenging conditions where traditional tapered insulation systems may become difficult to coordinate or install efficiently. The result is a monolithic roof assembly capable of accommodating complex geometry, transitions, and elevation changes while maintaining consistent substrate conditions for the roofing system.

LWIC roof deck contractor completing a roof deck installation project

When to Use It

LWIC roof systems are ideal for flat and low-slope roofing applications where long-term drainage performance, substrate stability, and installation flexibility are important. The monolithic nature of the system allows it to accommodate complex roof layouts, varying elevations, penetrations, and challenging transitions while providing a durable and consistent roofing substrate.

Why use LWIC

Consistent Insulation Performance

LWIC maintains a stable R-value over time, unlike insulation boards that degrade and lose performance.

Reroofing Without Full Tear-Off

The LWIC deck remains in place during reroofing, allowing only the membrane to be replaced and reducing cost, time, and waste.

Integrated Slope and Drainage

Slope is built into the system during installation, eliminating the need for layered insulation and reducing drainage issues.

Stable, Durable Substrate

LWIC provides a solid, continuous base for roofing systems, reducing movement and improving long-term membrane performance.

Bonded System with Uplift Resistance

LWIC adheres directly to approved substrates, contributing to wind uplift resistance without relying on mechanical attachment.

Fire and Assembly Performance

LWIC is a non-combustible material used in fire-rated roof assemblies and, in many applications, can help eliminate the need for supplemental under deck fireproofing.

Common Applications of Commercial LWIC Roof Decks

LWIC roof deck installation project for commercial building
Reroofing Over Existing Decks
LWIC roof deck contractor performing installation services
New Construction Roof Systems
LWIC roof deck installation for complex roofing layouts
Complex Roof Layouts
LWIC roof deck installation for commercial building
High Wind and Coastal Projects

Why Partner with Bonitz of Georgia for LWIC Roof Deck Services?

Decades of Experience Completing Complex Projects

We’ve worked through projects where deck conditions vary, elevations shift, and layouts don’t match plans exactly. That experience shows up in how we plan and install the system so slope and drainage perform as intended.

Expertise With Pre-Spec Services

We work with design teams early to define slope strategy, system selection, and detailing before construction starts, reducing revisions and field adjustments later.

Emphasis on Execution and Problem Solving

Most issues show up during install. We handle deck installation, LWIC placement, and coordination with roofing so problems are addressed in sequence, not passed between trades.

Controlled Scheduling

LWIC placement, cure time, and roofing installation are planned together. That keeps crews moving and avoids delays caused by rework or misaligned scopes.

Single Contractor Across Multiple Scopes

One contractor handling adjacent scopes removes ambiguity around responsibility. Fewer gaps between trades means fewer coordination issues and a more predictable install.

Pre-Spec Services for LWIC Roof Decks

Our team of experts works with architects, engineers, and roofing consultants to specify their roof deck system before the project begins. We value engineer your project to meet your building’s needs while maximizing your budget. Our design assistance includes:

  • Product/system selection for new construction or re-roof

  • Field analysis of existing roofs, roof decks, and limited structures

  • Roof/slope plan

  • R-value calculation

  • Guide specifications

  • Budget pricing

LWIC roof deck contractor on a job site
Metal Roof Deck Panels

Bonitz of Georgia Is a Leading Installer of Metal Roof Decks With LWIC

Lightweight insulating concrete (LWIC) is often combined with galvanized steel deck to create a composite roof deck system yielding superior vertical loading, diaphragm, and wind uplift. We have decades of experience not only assisting in the design of these systems but actual hands-on knowledge of how the systems come together in the field. These combination systems range from standard metal roof deck to form deck and even to metal acoustical roof deck systems.

Our LWIC Roof Deck Installation Process

1. Pre-Spec Coordination

We review deck conditions, drainage requirements, and project constraints early to align scope, slope strategy, and system approach before installation begins.

2. Mix Design & Technical Review

Mix design, EPS layout, and system details are confirmed based on project requirements to ensure slope accuracy and compatibility with the roofing system.

3. Pricing & Submittals

Detailed pricing and submittals are developed to reflect actual scope, including slope plans, material specifications, and system components.

4. Installation Plan & Placement

Deck preparation, EPS installation, and LWIC placement are sequenced to establish slope and deliver a consistent substrate ready for roofing.

5. Documentation & Closeout

Installation is documented and closeout materials are provided to verify system installation and support long-term performance.

Southeast commercial construction company service areas on a map

Where We Work

Backed by generations of regional experience, our LWIC roof deck installers serve construction projects throughout Southeast USA. We also support select projects outside the region based on scope and project needs.

  • Georgia

  • Florida
  • North Carolina
  • South Carolina

Bonitz of Georgia is proud to be a member of

NRDCA - national roof deck contractors association
NRCA - National roofing contractors association
AGC of Georgia
AIA
GA-RCA - Georgia roofing contractors association logo
AWCI - Association of the wall and ceiling industry logo

Frequently Asked Questions

Our team is ready to discuss your project and help you find the right solution.

More Questions? Call Us Today

+1 912-964-7155

LWIC roof decks need to be evaluated as part of the full roof assembly, not as a standalone product.

The structure must be able to support the added dead load. The slope design, including drain locations and elevations, needs to be clearly defined early. The type of roofing system being installed on top also matters, since compatibility and sequencing will affect performance and warranty.

Mix design, thickness, and installation conditions all play a role in how the system performs. Coordination between structural, roofing, and LWIC scopes is critical. Most issues in the field come from gaps in that coordination, not the material itself.

LWIC roof decks should be allowed to cure in accordance with manufacturer recommendations and project requirements prior to the installation of roofing systems.

Under typical conditions, roofing operations may begin within approximately 72 hours, depending on weather conditions and project-specific variables.

While initial costs vary by project, LWIC roof deck systems can provide significant value by incorporating fire resistance and roof slope requirements within a single installed system. This can simplify installation, reduce the number of materials and trades involved, and in many cases reduce overall project costs. When incorporated early in the design process, LWIC systems may also provide opportunities for structural deck optimization and enhanced uplift performance, subject to project-specific requirements and tested assemblies.

Additionally, LWIC roof deck systems can simplify future reroofing and renovation projects, potentially reducing demolition, labor, and replacement costs throughout the service life of the building.

Yes. LWIC roof deck systems can contribute to sustainability efforts by reducing material waste over the life of the building. Because LWIC systems can often remain in place through multiple reroof cycles, they may reduce demolition, replacement materials, and landfill waste. Additionally, LWIC systems are designed to provide stable thermal performance over time, which can contribute to long-term energy efficiency and reduced operating costs.

Yes. LWIC serves as the insulation system of the roof assembly but is not intended to function as the finished roofing surface. A compatible roofing system must be installed over the LWIC deck as part of a complete roof assembly. Proper coordination between the LWIC and roofing systems is critical to achieving the desired performance and longevity of the roof system.

Yes. These sessions focus on how LWIC is actually used in the field.

They cover when it makes sense to use it, where it does not, how it compares to other systems, and the common issues that come up during design and installation. The goal is to help teams make informed decisions on real projects.

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