The second product of the company is the waffle mold  hollow slab. The idea of two-sided waffle slabs introduced with non-resilient templates in the first half of the 20th century  and It used in the United States since 1940 And due to its efficient performance in ceilings with large spans, its use rapidly increased. In Iran, many of the important buildings and infrastructure such as universities, hospitals and hotels, etc., have been built using this technology.

The molds design of the company Gonbad-Firooz With great technical and economic benefits compared to the existing ones in the market.  The roof is made of composite plastic, which is very light and its glossy surface causes the bottom concrete view to be featured.


The slabs are also introduced in the 9th section of the National Building Regulations, with Title”Grid slabs”, Its design criteria is using orthogonal T shaped beams.

Possibility to transit the installation pipes from concrete joints before concrete laying

pretty Exposure view Under the ceiling (4-Piece Flower Design).

The optimal and square dimensions of 80 to 80 mold reduces the consumption of concrete and

rebar compared to other smaller and larger molds.

No need for a separate mold for closing down the middle joists by creating  ۳ cm seat at the edges of the mold   And the use of a box in width of 6 cm or a Scaffolding pipe for roof construction

Occupy the least storage space in the workshop environment results in the insertion of templates into another one and low cost transportation

The mold is very strong , and due to impact and throwing from the height, no cracks or fractures are created on the mold.

One of the new technologies used in the building industry is the use of permanent and non-permanent molds made of polypropylene among the slab and removing excess concrete, which reduces the weight of the slab and as a consequence of reducing the consumption of rebar and concrete in the entire structure.

In the technology mentioned, a hollow slab with double-sided joists is created using permanent and non-permanent molds. It should be noted that this technology has been approved by the Iranian Research Center for Roads and Housing and Urban Development.

The amount of consumed materials in the structure depends on factors such as seismic zone , the number of floors, the amount of shear walls, the regular plane , control , the type of the sidelong freight system, etc. Generally, a hollow slab system for buildings with spans longer than 6 meters can be economically justified. Various factors including:

The number of floors, the amount of shear walls, the length of spans , the type of use and loading ,structural discipline, the seismic zone, the type of soil, the layout of the columns, etc., in the design of the structure, the amount of rebar and concrete consumption are effective. For this reason, company Gonbad Firoozeh for helping the optimal system selection by the employer for each project, it provides free initial advice and design. The following table can be used to estimate the limits.

The following are the average values for the projects implemented are moderate and high in earthquake conditions, and the average span is 9 to 11 meters.