By the PPA Funding team Last updated
It can, if the work is done without the roofer being involved. Drilling fixings through a roof covering may void the manufacturer or installer warranty on that covering. Using non-penetrating or manufacturer-approved mounting, and getting written sign-off from the original roofer, usually keeps the warranty intact. Always check before any panels go on.
Can solar panels void a roof warranty?
A roof covering usually carries its own guarantee, from the tile, membrane or metal-sheet manufacturer and sometimes from the roofer who laid it. Fixing solar to that roof involves penetrations or added weight, so a poorly planned installation can give the manufacturer grounds to reject a later claim, arguing the failure came from the mounting rather than the material.
This is a contractual matter rather than a safety one, and the terms differ between products. Some warranties allow approved solar fixings, some require the original contractor to carry out or approve the work, and some are silent, which is where disputes start. The wording of your specific guarantee decides the outcome, so read it or take advice before committing.
How do fixings protect the roof covering?
On pitched tiled or slated roofs, mounting hooks sit under the tiles and bolt to the rafters, which keeps the weatherproof layer largely undisturbed when fitted correctly. On flat roofs, ballasted systems weigh the array down with blocks and avoid piercing the membrane at all, which many single-ply membrane makers prefer.
Where penetrations are unavoidable, using the covering manufacturer’s own approved brackets and sealing details keeps the work inside the warranty terms. A competent installer will match the mounting method to the roof type and its guarantee, not use one approach everywhere.
How do you get the roofer to sign off?
The cleanest route is to involve the company that installed or guarantees the roof before work starts. Ask them to confirm in writing that the proposed solar fixings are acceptable, or to carry out the penetrations themselves, so the covering guarantee stays valid.
Keep that confirmation with your solar paperwork, alongside the installer’s own workmanship warranty for the mounting. If the roof is older or near the end of its life, it can be worth recovering it before the panels go on, since removing an array later to fix a roof is costly. A funder assessing a PPA or lease will often want the roof condition confirmed anyway.
This guide is general information, not financial or tax advice. Your circumstances determine what applies — please confirm with your accountant or advisor. Get a tailored proposal →
Frequently asked questions
Will a solar installer check my roof warranty for me?
A good installer will ask about the roof age, construction and any existing guarantee, and choose a mounting method to suit. They cannot see the wording of your roof warranty unless you provide it, so share the documents early and ask them to confirm the fixings are compatible in writing.
What if my roof is too old for solar?
If the covering is near the end of its life, installers often recommend replacing or overhauling it before mounting panels, because taking the array off later to repair the roof adds cost. Under a PPA or lease, the funder may also require evidence that the roof will last the term.
Related guides
- Commercial solar and REGO certificates: green certificates for the electricity your panels generate
- Commercial solar and PPA jargon glossary: the key terms a business owner meets, in plain English
- Solar battery round-trip efficiency: the energy lost when you store and return electricity
See our funding options, commercial solar and solar by industry pages.