How a commercial array is fixed to your roof.

From your roof type and its structure. A flat membrane, a trapezoidal metal deck, a standing-seam roof and an open ground site each call for a different method, and the fixing detail and the loads are confirmed by the structural survey and the wind-load assessment for your building. We do not choose the method from a page; it comes from the survey.

No. A ballasted system sits on the membrane on protective mats and is held down by weight, so nothing pierces the waterproofing. That keeps the roof's weathertightness and the existing membrane warranty intact. The ballast needed to resist wind uplift is a structural calculation for your roof, and the weight the roof then carries is checked against its spare capacity in the survey.

A trapezoidal roof is fixed through the sheet with self-sealing fasteners, made watertight at each point, so it is a penetrative method. A standing-seam roof is clamped: a non-penetrative clamp grips the raised seam and the rail mounts to the clamp, so nothing pierces the sheet. The clamp and fastener detail are matched to your exact roof profile in the survey.

When the roof rules itself out, through limited area, a structure that cannot carry the array, or shading. A ground-mounted frame on an open site is founded to a ground investigation, commonly on driven steel piles, and it frees up the orientation and tilt a roof cannot offer. It brings land take, cable run, planning and security into the picture instead, which we model against your site.

Yes, in two separate ways. The wind case is harder because there is nothing upwind to slow the air, so the holding-down pattern is zoned rather than repeated, with heavier restraint at the roof edges and corners. The corrosion case is harder because the air carries chloride, so the fasteners, coatings and connectors are specified from the atmospheric corrosivity category rather than an inland default. Our page on coastal and exposed sites sets out both, including the exposure terms assessed under BS EN 1991-1-4 and the materials schedule an exposed roof needs.

It can. Bifacial modules add yield where the surface behind the array reflects light, which favours a ballasted flat roof or a light-surfaced ground-mount over a dark metal roof, and that gain is modelled in PV*SOL for your roof rather than assumed. Cell technology, N-type TOPCon, heterojunction or PERC, is matched to your roof and your load in the design, with no single type treated as best for every site.

The mounting method does not set the price on its own. The figure comes from the on-site survey and a PV*SOL model run against your half-hourly load, not from a price list, because the array size, the roof or ground works and the connection all move it. We confirm the system cost in the written proposal once the survey is done. Our commercial solar cost guide explains what shapes it, and finance covers how it can be funded.

The mounting type rarely sets the timeline. The survey reaches you quickly from our Yorkshire base, and the programme is then paced by the G99 connection to your DNO rather than by travel or panel lead times. A dated programme comes with your proposal once the survey and the connection position are known. Our installation timeline guide walks through each stage.