Solar Panels for Every Roof Type

Choosing the Right Mounting System for Your Roof

The variety of mounting systems available today means there is a proven, weatherproof solution for virtually every roof type found in Wiltshire — from Georgian slate townhouses in Bradford on Avon to modern concrete-tiled new builds in Chippenham to barn conversion roofs with standing seam metal in the Cotswolds. Understanding how your specific roof affects the installation helps you have a more informed conversation with your installer and understand why one approach is recommended over another.

Tile hook systems — used on concrete interlocking and clay tiles — are the most common method. The hook slides under a lifted tile and bolts directly into the rafter below. No tile is drilled or penetrated; it is simply lifted and replaced over the hook. The critical detail is that hooks must be positioned over rafters, not just anywhere in the batten cavity. This requires the installer to locate rafters accurately before lifting any tiles, which is one reason experienced installers work more quickly on this roof type — they know exactly what they are looking for.

Slate installations are more involved because natural slate is both more fragile and more valuable than concrete tiles. Specialist slate hooks — often called "top fix" hooks — are designed to be fixed at the head of the slate rather than penetrating the body of the tile. Adjacent slates must be carefully lifted without cracking, and any slates damaged during installation must be replaced like-for-like. We always attend slate roof installations with a selection of replacement Welsh, Spanish, and reclaimed slate to ensure a clean finish regardless of what happens during access.

Flat roofs deserve particular attention because they are frequently misunderstood. A flat roof is not horizontal — building regulations require a minimum fall of 1:40 (approximately 1.4 degrees) to allow rainwater drainage. Solar panels on a flat roof are installed on tilt frames, which allow the installer to set the panel angle independently of the roof surface. This is actually an advantage: you can orient panels precisely at the optimal 30-35 degree pitch regardless of the roof's original orientation. The two mounting methods are ballasted (held in place by weight — rubber paving slabs — without any roof penetrations) and mechanically fixed (bolted to the roof deck). Ballasted systems are quicker to install and avoid any penetrations, but require a structural survey to confirm the roof can handle the additional point loading.

Heritage Roof Types: Specialist Approaches

Wiltshire's unusually high concentration of heritage properties means we regularly work on roof types that many installers rarely encounter. Natural Cotswolds stone slate — distinctive honey-coloured limestone tiles used throughout the North Wessex Downs and Cotswolds AONB — requires the same specialist handling as Welsh slate, with the added complication that matching replacement stones can be harder to source. We maintain a stock of reclaimed Cotswolds stone and can source matched replacements through specialist reclaim merchants in the region.

Clay peg tiles, common on period properties in the Avon valley and Somerset border, have a distinctive double-lap construction that is more time-consuming to work with than interlocking concrete tiles. The steeper pitch typical of clay tile roofs (often 45 degrees or more) also requires more careful scaffolding design. These factors are reflected in our survey assessment — they are not complications that catch us off guard, but they do affect installation time and cost.

For all heritage roof types, we recommend discussing your options with your installer in the context of any conservation area or listed building considerations that apply to your property. In some cases, the preferred panel type for planning purposes (in-roof integrated systems) also happens to be the gentlest approach for the roof covering — avoiding the need to lift and replace individual tiles entirely and instead replacing a section of roof with a watertight panel array.

What About Roof Orientation and Pitch?

Beyond the roof covering, orientation and pitch matter for performance. South-facing roofs at 30-40 degrees are optimal, but east-west splits and pitches from 15-50 degrees still deliver excellent results. During our free survey, we use specialist software to model your specific roof geometry and calculate expected generation down to the kWh.

Flat roofs actually offer flexibility — we install tilt frames that orient panels to the ideal angle regardless of the roof's orientation. This makes flat-roofed extensions and garages excellent candidates for solar.

Do Panels Cause Roof Leaks?

When installed correctly by MCS certified installers, solar panels should never cause roof leaks. Every roof penetration is sealed with appropriate flashing or weatherproofing. We guarantee the weathertightness of every installation we complete.

In our experience, most leaks attributed to solar panels are caused by poor installation practice: inadequate flashing, damaged tiles during access, or incorrect bracket placement. This is why choosing an MCS certified installer matters — the installation standard (MIS 3002) specifies exactly how roof attachments must be made.