Properties and features of installing roof materials on a standing seam roof base

If your house has an old standing seam roof, you should not remove it — it can serve as an excellent base for new materials, provided that its sheets have not rusted through and have not deformed during service. Flexible roofing, for example Technoelast or Uniflex, can be easily laid on a standing seam roof. Any polyester-based roofing material with an elongation at break of 30–50% is suitable for renewing the roof surface. This is necessary to compensate for thermal deformation between the old and new roofing. A glass-fiber-based material cannot be used in this case — its elongation at break is only 3%, which is clearly insufficient for proper installation and long-term service of the roof. Also, materials based on glass mat should not be used on a standing seam roof — such a roof will require repairs already in the second year after the start of operation.

Before carrying out construction work, the standing seam roof should be thoroughly prepared. This preparation consists of leveling the roof surface — for this purpose all seams are bent toward the roof surface. Roofing sheets are fastened in the center with nails so that they do not bend in waves. If a drainage/gutter system is installed on the standing seam roof, part of it is deformed and reinstalled after the entire profiled sheet or flexible shingles have been laid.

If it is planned not to install a drainage system on the roof, the roofing membrane is laid on the roof in two layers, arranging the rolls according to SNiP requirements. If the roof slope is between 15% and 35%, the roofing surface is additionally secured with a metal strip perpendicular to the roof slope. Material laid on a standing seam roof must be securely fastened at both the ridge and the eaves.

If the roofing membrane adjoins pipes, windows or other structures, such as vinyl siding, they must be fixed at the top with a clamp or batten.

Before starting roofing work, the condition of the standing seam roof should be checked from inside the building by entering the attic. Very often, due to installation defects, condensation accumulates on the inner surface, which leads to corrosion of the standing seam roof. If it has severely rusted, it is not advisable to lay new roofing material on it.