This application enables the preliminary sizing and selection of cast-in-situ concrete slabs for multi-storey buildings. The user has the opportunity to select within a wide range of slab types span dimensions and loadings depending on his needs and aim. Once the input data (slab type span and loading) are filled the application gives the preliminary thickness of the slab (as the most economical option) and a first estimate of the necessary reinforcement quantities. The application can be used by practicing engineers and architects as well as students or other related professionals.

Procedure:
- Step 1 is ‘selection of the appropriate SLAB TYPE’. The user has the possibility to select one of the following options. When the user selects the option the photo of the respective slab type appears in order for him to see if he has selected the right one.
a. One-way solid slabs (single span)
b. One-way solid slabs (multiple span)
c. Ribbed slabs or one-way joists (single span)
d. Ribbed slabs or one-way joists (multiple span)
e. Two-way solid slabs (single span)
f. Two-way solid slabs (multiple span)
g. Waffle slabs two-way (single span)
h. Waffle slabs two-way (multiple span)
i. Flat slabs (multiple span) (photo css-09)

- Step 2 ¬¬is ‘provide the necessary INPUT data’. These data are:
a. CHARACTERISTIC IMPOSED LOAD which is a uniformly distributed load over the slab surface expressed in (kN/m2). The possible values for the characteristic imposed load are:
 2.5 – general office loading; car parking;
 5.0 – high specification office loading; file rooms; areas of assembly;
 7.5 – plant rooms; storage loadings;
 10.0 – storage loading
b. SLAB SPAN expressed in (m). All the possible values for each slab type are in the tables in Excel.

- Step 3 ¬¬is ‘calculation of the OUTPUT data’. These data are:
a. Recommended and most economical SLAB THICKNESS expressed in (mm). The respective values for this data are in the tables in Excel.
b. Necessary reinforcement quantities for 1m2 of slab expresses in (kg/m2). The respective values for this data are in the tables in Excel.