When strengthening a roof structure for a solar geyser system, the objective is to spread the additional load over the widest roof area possible.

The size of the timber used, should mirror that which is in the existing roof structure (usually structural timber, such as pine, measuring: 114x38mm – SABS approved). In no way should the existing roof structure or parts thereof be removed, cut away or into.

The strengthening of the truss should be done directly under the area where the solar geyser is to be positioned. As seen in the diagram, Side View 2, the strengthening should be secured to the rafter and be extended one
meter past either side of the solar HWC. All the rafters that are subjected to the load should be strengthened; not just one or two directly under the solar HWC, as seen in the diagram (Top View 2)


Further strengthening can be done by securing a piece of structural timber, measuring 114x38mm, and perpendicular to the rafters, as seen in the diagram (Top View 2)


If applicable, this timber must be secured to the underside of the 38x38mm brandering; otherwise, the roof tile will not fit back in place. As with the strengthening of rafters the perpendicular bracing needs to extend past either side of the solar HWC, to the first rafter after the solar HWC.

strengthening an existing roof structure for a solar water heating system

For more complex situations or if you are in doubt, an expert should be consulted.