Concrete Pouring

Elastizell LWIC

Elastizell Insulating Concrete Roof Decks:

An Effective New and Reroofing Solution

Basic Product

Elastizell is 100% Portland Cement and contains no water-absorbing expanded fillers. Elastizell requires only one-fourth the mix water of expanded aggregate insulating concretes. A common misconception is that all insulating concretes have high water content. Elastizell does not! Elastizell obtains its workability from discrete air cells, not from excessive water.

Cost-Saving Solutions for New and Reroofing Problems

Elastizell solves reroofing problems because of its many advantages. Its superiority over insulation board is evidenced by the fact that Elastizell Roof Decks are permanent, economical, and last for the life of the building.

Advantages of Elastizell Insulating Concrete Roof Decks

  • Positive slope-to-drain eliminates drainage problems and standing water

  • Substantially improved thermal insulation values when combined with EPS insulation board for both new construction and reroofing

  • Typically eliminates future roof insulation tear-offs and the potential for additional damage during reroofing

  • Ideal base for built-up or single-ply membranes which may be installed two to five days after casting. These may be ballasted, fully adhered, or mechanically attached

  • Strong, permanent, nailable roofing base with improved fire resistance

  • Economical; saves both time and money

Pertinent Information:

Elastizell Advantages Over Insulation Board

Customized Slope-to-Drain

The primary purpose of a roof system is to protect the interior of a building from outside environmental occurrences. Proper slope-to-drain eliminates ponding which accelerates membrane aging and leads to roof leaks. Tapered insulation is only effective on simple drainage patterns with few penetrations.

An Elastizell Roof Deck System achieves positive drainage in new and reroofing construction. The actual installation is cast to a positive slope. It corrects and adjusts field differences which always occur between drawings and the actual rooftop conditions.

Few roof decks have regular drainage patterns or built-in slopes for positive drainage. The Elastizell system achieves positive drainage by combining a stair-stepped, slurried EPS insulation board with on-deck custom sloping of Elastizell. Standard rigid board cannot do this and tapered board systems are costly and inefficient.


Mechanically attached insulation board systems have extensive and confusing fastening requirements. Fasteners penetrating structural decks provide a passageway for air underneath the deck and immediate uplift problems.

Integral System

The high insulating value of Elastizell Roof Decks is improved by encapsulating EPS board within the system.

EPS board is slurried to the deck in new construction or to the existing roof membrane in reroofing applications. The slurry bonds the EPS to the deck and completely fills depressions and deck flutes which are not filled with an insulation board system. Elastizell encapsulates insulation for high resistance to uplift, fire, and seismic forces.

The cast-in-place Elastizell sandwiches the slurried EPS Insulation board to the deck, creating an integral system. No deck penetrations weaken the system and stress-causing joints directly under the roofing membrane are eliminated.

Heat Sink

The Elastizell and EPS board provide a heat sink beneath the roofing membrane that moderates the temperature changes which cause thermal shock twice daily - heat from the sun and cooling at nighttime or by rain.

Insulation board next to and under the roofing membrane cannot absorb this heat resulting in greater thermal shock which eventually fatigues and splits the membrane.

Permanent Insulation

The Elastizell system is permanent insulation which performs better than rigid insulation. Rigid insulation board acts like a sponge. It soaks up leaking moisture reducing the insulation value. Once a roof leaks over rigid board, the entire roof system - membrane and insulation board - must be replaced. Not so with Elastizell as the EPS insulation is totally encapsulated. With the Elastizell system, only the failed membrane is replaced.

Elastizell insulation fills the flutes of metal deck systems so that air infiltration is eliminated. The Elastizell system has neither the joint problems nor the thermal drift characteristics associated with rigid board insulations.

Fire Rated

Elastizell Roof Decks have numerous fire ratings. Elastizell is noncombustible. It does not require fireproofing the steel deck or a separate thermal barrier which rigid board systems MUST have. Since the flutes are filled, this fire channel is eliminated.

Wind Uplift

The Elastizell Roof Deck is an air retarder improving wind uplift performance as evidenced by its numerous UL and FM ratings. Elastizell bonds the EPS board to the structural deck, filling depressions and deck flutes.

Low Cost

The Elastizell Roof Deck System is less costly than rigid insulation board systems. The EPS insulation is slurried into place and bonded to the substrate. No mechanical fasteners are required. Once the Elastizell Roof Deck is cast, installation of the membrane is continuous and fast.

Mass Effect

The mass effect of Elastizell insulation beneath the membrane moderates temperature fluctuations and reduces thermal stress. Low density, rigid insulation next to the roofing membrane results in higher temperature fluctuations and greater thermal stress on the membrane.


No roof system lasts forever. When a membrane fails over rigid board insulation, the entire system must be torn off, (consequently exposing the building's contents) and replaced. Rigid board is damaged by water and is not cleanly torn off. Elastizell Roof Decks are not damaged by water and the encapsulated EPS board, the heart of the insulating system, is completely protected. With an Elastizell Roof Deck System, only the roofing membrane need be replaced.