Guide to repair and waterproofing of Jack Arch Concrete Roof

Jack Arch Roof

Jack arch Roof construction can be done in brick or concrete. The arch of the Jack arch roof is either made of brick or of concrete. The arch is supported on the lower flange of mild steel joists (RSJs).  The rolled steel joists are supported at their ends on the walls or on the longitudinal girders. They are spaced at a distance of 1m to 1.5m centre to centre.

Jack arch Roof - Detailed Section
Jack arch Roof - Detailed Section

The rise of the arch is kept equal to 1/12th of the span. Layer of concrete is then poured over the roof to straighten the roof. The  concrete layer thickness over the crown of the arch is not less than 15cm.

Due to the super-imposed load on the arch, tension develops at the ends of the arch. Steel tie rods are placed at the ends of an arch with a suitable spacing of 1.8m to 2.4m.

In this article, we are going to study the causes for leakages in a Jack Arch Roof and remedy to solve the problem of leakage.

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