More homes in London and the South East are fitting solar panels. Most installers check whether the roof can take them, but their focus is on the panels. The roof underneath may already be decades old.
If the roof needs repair or replacing in a few years, the panels will usually have to be taken down and put back. This guide explains why it pays to check an older roof first and what to look at.
Why the roof’s condition matters
Panels are fixed to the roof structure with brackets that pass between or through the slates or tiles. Once they’re on, the part of the roof under them is hard to see and harder to reach. Any repair under the panels means removing them first. That adds cost and time to what might otherwise be a simple job.
It makes sense, then, to know the roof is in good shape, or to deal with any problems, before the panels go up.
What to look at on an older roof
- The coverings. Slipped, cracked or missing slates or tiles. On old slate roofs, widespread slipping can point to nail fatigue.
- The underlay. Old bitumen felt can be brittle, and very old roofs may have none at all.
- Battens and timbers. Signs of rot, damp or sagging, as far as can be seen from the loft.
- Ridges, hips and flashings near where the panels will go.
- Gutters on the side with the panels, as these can be harder to reach later.
Age and material
Natural slate can last 100 years or more, and clay and concrete tiles commonly last 50 years or more. But the fixings and underlay often fail sooner. A roof that looks fine from the street may still have tired battens or failing nails. Our guide to roof lifespans explains this in more detail.
Some materials need extra care. Old slate is easy to crack when brackets are fitted. Handmade clay tiles may be hard to match if any break. On listed buildings or in conservation areas, panels may need permission. Check with your council.
Want a roof surveyed? We cover London and the South East, with written reports and photos from £150 including VAT. Book a survey or call 07833 053749.
Flat roofs and panels
Panels on flat roofs are often mounted on frames held down by weights or fixed through the membrane. Either way, the roof covering under them needs to be in good order. A flat roof near the end of its life is best dealt with before frames go on. See flat roof problems.
After the panels go on
It’s worth keeping an eye on the roof after installation. Watch for new damp in the loft, especially around bracket positions, and for slipped or broken slates or tiles near the panels. Birds sometimes nest under panels, which can block gutters with debris. Check the gutters from the ground after heavy rain.
How a survey helps
A roof survey before installation gives you an independent record of the roof’s condition. You can share it with your solar installer and any roofer. If the work has already been done and you’re worried about the roof, a survey can look at what’s visible around the panels and in the loft. Where applicable, a drone can photograph the roof without anyone walking on it.
Quick answers
Can you see under solar panels?
Not directly. We can photograph the roof around them and check the loft where there’s safe access for signs of damp.
Will fitting panels damage my roof?
A careful installation shouldn’t, but slates and old tiles can crack when brackets are fitted. Check the loft and roof afterwards for new damp or breakages.
Should I replace my roof before fitting solar panels?
Only if it needs it. A survey helps you decide whether the roof is likely to need major work soon.
Related services
More advice
- How Long Does a Roof Last? Slate, Tile, Flat
- Slipped Slates and Nail Fatigue Explained
- Roofs on Listed Buildings and in Conservation Areas
- What Does a Roof Survey Include?
- All advice
This guide is general information about roofs and roof surveys. It isn’t legal, insurance or structural engineering advice; for those, speak to a suitably qualified professional.