RETROFIT / REROOFING Loadmaster – Lightweight Insulating Concrete – Poured Gypsum Roof Decking

Structural composite roof deck assemblies have been widely used throughout the USA for many, many years.  They have provided excellent long term performance at reduced costs to thousands of buildings across America.  Starting in 1940, poured gypsum roof decks was the first structural composite assembly followed in the early 50’s by lightweight insulating concrete roof decks (LWIC) and in the late 60’s by Loadmaster composite steel decks. These three systems make up the majority of structural composite roof deck assemblies in existence.

LWIC Loadmaster Retrofit-1

Retrofitting structural composite roof deck assemblies is substantially different than retrofitting many other types of roof deck assemblies.  In conventional deck construction the deck is the sole structural entity and provides all the structural performance of the assembly. It alone provides gravity load resistance, wind uplift resistance and diaphragm shear resistance for horizontal wind and seismic loads. The steel deck  alone must be retrofitted if necessary to maintain structural capacities.  In structural composite assemblies the structural strength is derived from the engineered structural attachment of all the components in the assembly. This engineered attachment creates a structural composite assembly which provides gravity load resistance, wind uplift resistance and diaphragm shear resistance for horizontal wind and seismic loads.  All the components must be retrofitted in a precise manner to restore or maintain the structural composite strength. This distinct structural difference MUST BE RECOGNIZED AND TREATED CORRECTLY in a retrofit or reroofing operation.  If not, the building can be left in a “dangerous” structural condition and subject to collapse  under high winds or seismic loads. The following will outline the correct procedure to retrofit / reroof these assemblies.


Loadmaster Retrofit Systems:

Loadmaster Roof Deck Retrofit System

LWIC Roof Deck Retrofit System

Gypsum Roof Deck Retrofit System

The following is an article directly concerning this subject that appeared in the January 2015 issue of RCI’s Interface magazine.

RCI Article 2015 – Retrofitting Structural Composite Roof Decks

Things You Should Know – Before Reroofing Loadmaster Roof Decks (PDF)

Things You Should Know – Reroofing Lightweight Insulating Concrete Roof Decks (PDF)