ISO double-threaded hanger bolt without mounting plate

It is the part that actually holds the panels on the roof: a long bolt with two types of thread, one at each end. One end is screwed into the timber of the roof, like an ordinary wood screw, and the other has a metric thread, like a threaded rod, on which the nuts and the connecting piece to the panel rail are fitted. This variant is supplied without the mounting plate, that is without the adapter that couples directly to the rail - that one is bought separately.

The variant without the plate makes sense when the connection to the rail is made differently: through an L adapter, a clamp or a support with height adjustment, or when the installer already has in stock the adapter matching the profile used. A practical advantage is that the fixing point can be raised or lowered by positioning the nuts on the metric thread, which helps to compensate for the unevenness of the covering - real roofs are never perfectly flat. The hole in the covering is sealed with an EPDM washer, a rubber that compresses on tightening and blocks the water. The length is chosen according to the thickness of the covering package and to how deep the thread must go into the timber.

Standard material stainless steel A2; usual sizes M10 in lengths of 180 / 200 / 250 mm and M12 in lengths of 200 / 250 / 300 mm. Sealing with an EPDM washer plus a metal washer. The anchoring capacity depends on the species and strength class of the timber and on the depth of the thread in the rafter; it is verified by calculation for pull-out and shear for the wind and snow loads at the site. The delivery does not include the plate or the rail mounting adapter.

Who it suits

Suitable for the installer who already has the chosen rail adapter or uses an interface other than the standard plate, on a roof with a timber frame.

Terms explained

• Double-threaded bolt (hanger bolt): A bolt with a wood thread at one end and a metric thread at the other, which connects the timber of the roof to the metal structure of the panels.
• Rafter: The inclined timber beam in the roof structure, the only element in which the bolt can be truly firmly anchored.
• EPDM washer: A rubber gasket that flattens on tightening and stops water from entering through the hole made in the covering.

Technical specifications

Recommended applications

• Anchoring the PV structure into timber rafters, through the covering
• Roofs of corrugated, trapezoidal or fibre-cement sheet
• Installation with a rail adapter chosen separately, according to the profile used
• Compensating for unevenness of the covering through adjustment on the metric thread

Technical details

Generic product — standard specifications

The article is the double-threaded bolt, hanger bolt type, supplied in the variant without a mounting plate, that is without the adapter that makes the direct connection to the rail. The bolt has one end with a wood thread, which is screwed into the rafter or into the boarding, and one end with a metric thread on which the washers, the sealing washer and the adjustment nuts are fitted, respectively the rail adapter purchased separately.

The variant without the plate is used when the connection to the rail is made through another type of element - for example an L adapter, a clamp or a support with height adjustment - or when the installer uses an adapter already in stock. It also allows height adjustment of the fixing point by positioning the nuts on the metric thread, useful in compensating for the unevenness of the covering.

The standard material is stainless steel A2, with usual sizes M10 and M12 and total lengths between 180 and 300 mm, chosen according to the thickness of the covering package and to the screwing depth required in the timber. The penetration is sealed with an EPDM washer compressed on the covering. The anchoring capacity depends on the species and strength class of the timber and on the depth of the thread in the rafter, and is verified by calculation for pull-out and shear for the wind and snow loads.