This research aims to introduce a new effective method to analyze and solve thin slabs that are exposed to heat flux in full over one surface, whereas the other surface is exposed to heat exchange with the surrounding. A new equation was introduced by the author in order to find heat distribution against the depth of the slab. The new equation is based on Lablace equations with consideration to heat exchange with the surrounds. It was found out that when heat exchange reaches zero (insulated), then the new equation is conformed to other equations in different references. Consequently, the coefficient of linear expansion of slab material (α) was put to function at temperature α(T). Therefore, the deflections of circular and rectangular simple support slabs were found. Hence, and according to this, bending moment, shear force and torsional moments could be found for these slabs.