Mounting solar panels on a standing seam roof

Fixings and rails

• Standing-seam roof: Standing-seam clamp (no drilling) → seam. Choose a clamp for the seam type (single / double / click).

Check before installation

• The seam type: single, double or click. Each needs its own clamp.
• The seam and rafter spacing: clamps go on the seams next to the rafters.
• The tightening torque in the clamp’s datasheet. The sheet is not drilled, so the clamp holds everything.

Calculation for three cities

A typical 12 × 7 m slope at 30°, rafters every 600 mm, 20 panels of 2,350 × 1,100 mm in 2 rows. Snow and wind under DBN V.1.2-2:2006 for the regional centre; a 6 m high house.

Uplift and pressure are the design forces on one fixing next to the typical capacity the calculation assumes. An array near the eaves or the gable lies in the wind edge zone, where the calculation places fixings closer together.

Where the fixing fails (Lviv), the calculation suggests placing fixings closer together or choosing a fixing with a higher datasheet capacity. The constructor shows the effect as soon as you change the spacing.

Drawings

Bill of materials for the typical roof (Kyiv)

20 panels, 11.00 kW. Quantities from the calculation for Kyiv; open the constructor for your own roof.

Installation step by step

The Solispec engine writes the steps for the typical roof in Kyiv: rafter numbers, marking out and quantities come from the same calculation. Steps that depend on the roof covering are given in full, those shared by all pitched roofs in short.

1. Roof inspection: from the attic, check the rafters (section ≥ 50×150 mm, no rot or cracks, spacing ~600 mm) and the condition of the roof covering.
2. Mark out the 11 180 × 4 720 mm array: 1 190 mm from the eaves, 410 mm from the left gable.
3. Fixings: place the standing-seam clamps (72 pcs) on the seams next to rafters №2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 (seams at their own pitch ~600 mm) on each rail line. The clamp must match the seam type. Tighten the screws per the datasheet (typically 15–20 N·m), do not drill the sheet. Check: the clamp does not rotate on the seam.
4. Rails: fix the rails to the brackets with T-bolt M8 (1 per fixing, 72 pcs), adjusting the bracket height so that the rails are in one plane.
5. Earth the array: bond the rails of each row to each other and to the rails of other rows with a 6 mm² Cu conductor via rail earthing clamps.
6. Make the cable penetration through the roof covering above the array: a penetration with an EPDM collar or a cable gland, sealant under the flashing.
7. Install the panels from bottom to top, starting from the gable.
8. Fix the cables to the frames and rails with stainless steel clips every 300–400 mm so that they do not lie on the roof covering or rub against its edge.
9. Install snow guards above the eaves below the array across the full width of 11 180 mm, fixed into the rafters.
10. Check the penetrations after the first rain (from the attic — for any traces of water).

The shared steps in full are on the section page

Common mistakes

• Taking a clamp «for any seam». It must match your seam type.
• Drilling the sheet «to be safe». A seam roof needs no penetrations — the clamp holds the fixing.
• Tightening the screws by feel. Torque per the clamp’s datasheet; once mounted the clamp must not turn on the seam.