Roof Leaking After Solar Panel Installation: What to Do

Noticing water inside your home after solar panels have been installed is stressful. The timing is rarely a coincidence. Most roof leaks that appear in the weeks or months following an installation have a direct cause — something was disturbed, damaged, or incorrectly fitted during the work. The key is to act quickly, document carefully, and put pressure on the right people through the right channels.

Don't panic — but do act quickly

Water damage does not stay static. Every rainfall event that gets into your roof structure carries additional risk: timber saturation, mould, damage to insulation, and eventually damage to ceilings and plasterwork. A small drip that appears minor in week one can cause hundreds of pounds of additional damage by week six.

Start protecting your home now, and pursue the installer simultaneously. The two things are not in conflict.

Common causes of post-installation roof leaks

Solar panels themselves do not cause roof leaks — the mounting system does, when it is fitted incorrectly or disturbs existing weatherproofing. The most common culprits are:

Incorrectly seated tile hooks. The most frequent cause. MCS installation standard MIS-3002 (sections 5.9.1 and 5.9.8) requires tiles to sit flat and undamaged after hooks are fitted. If a hook is placed at the wrong depth, or if the tile is not properly re-seated, a channel opens up that rainwater can follow directly into the roof space. Incorrectly seated tiles are visible from the ground if you know what to look for — look for tiles that appear slightly raised or misaligned compared to those around them.

Tiles cracked or broken during installation. Roofers and solar installers both know that roof tiles can crack under foot traffic or tool pressure. A cracked tile is an immediate leak point. A competent installer spots and replaces cracked tiles before leaving site.

Sealant failure around cable penetrations. Where DC cabling passes from the panels through the roof into the loft space, that penetration must be sealed. If sealant was not applied properly, or if the wrong type was used, it degrades and opens a water entry point. These are often slow, dripping leaks that only appear during sustained rain.

Displaced lead or tile flashing. Where the roof meets a wall, chimney, or dormer, lead flashing or proprietary flashing strips create the seal. If installers walk on or disturb existing flashing without re-dressing it, the seal is broken.

Roof membrane punctured during bracket installation. Below the tiles, many roofs have a breathable roofing membrane. Bracket bolts that are positioned incorrectly or driven without care can puncture this layer, letting driven rain through even if the tiles themselves look intact.

Wrong hook type for the tile profile. Not all tile hooks are universal. A hook designed for a flat concrete tile used on an S-profile clay tile will not seat correctly and will leave gaps. MIS-3002 requires that the correct hook type is selected for the tile in use.

How to identify where the water is getting in

The place where water appears inside your home is rarely where it enters the roof. Water travels along rafters, sarking felt, and ceiling joists before dripping, often appearing metres away from the actual entry point.

Check the loft space during rain. This is the most reliable way to locate the source. If you have loft access, get up there during a rain event (with a torch and appropriate caution) and look for:

• Active drips or wet patches on the rafters or felt
• Water tracking lines — dark staining that shows the path the water has taken
• Wet insulation, which is sometimes the only sign before the drip reaches the ceiling

Photograph everything from above. Date-stamped photos of wet timber or felt are significant evidence when making a warranty claim.

Check around cable entry points on external walls. Where conduit or cable enters the building through an external wall, check the wall below in the loft for damp patches or salt crystallisation (white powdery deposits), which indicates regular moisture ingress.

Who is responsible?

The installer is responsible. This is not ambiguous.

When a solar installer fits a mounting system, they take on responsibility for the weathertightness of the penetrations and disturbances they have made to your roof. If a leak appears in the area of the installation and no other work has been done to your roof, the burden of proof is firmly on the installer to show they did not cause it — not on you to prove they did.

Workmanship warranty. Your installation contract should include a workmanship warranty, typically for two years, sometimes longer. Roof weathertightness is covered by workmanship.

MCS installation standards. If your installer is MCS-certified, their work must comply with MIS-3002. Sections 5.9.1 and 5.9.8 specifically address tile hook installation and the requirement that tiles are left in a weathertight condition. You can reference these clauses directly when contacting the installer.

Insurance-Backed Guarantee (IBG). MCS-certified installations include an IBG as a condition of certification. If the company has ceased trading, the IBG provider covers valid workmanship claims. See the related article on what to do if your installer has gone bust for the full process.

What to do immediately

1. Place containers and protect belongings. If water is actively dripping, put down containers and move anything valuable away from the affected area. This is not an admission that the problem is minor — it is just sensible damage limitation.

2. Photograph everything with timestamps enabled. Take photos of the drip location, any staining on ceilings or walls, and the loft space if accessible. Make sure the date and time metadata is embedded in the photos, or take a photo of today's newspaper or a clock alongside the damage. These photos are your evidence.

3. Contact your installer in writing. Email, not just phone. A phone call can be denied later; an email creates a paper trail. Keep the tone factual: date of installation, date the leak was first noticed, brief description of where the water appears. Attach your photos. Ask for a written acknowledgement and a proposed date for inspection.

4. Do not authorise any other contractor to carry out repairs yet. If you get a roofer in to fix the damage before the installer has assessed it, the installer's solicitors will argue that the third party caused or obscured the original fault. Get the installer to inspect first — unless there is active major structural risk that requires immediate intervention.

Getting it fixed under warranty

Your installer should attend the property at no cost to you, inspect the affected area, identify the cause, carry out any necessary repairs to the roof, and refit any tiles or sealant properly. They may need to temporarily remove one or more panels to access the mounting system — this should also be at their cost.

If the installer tries to charge you for the visit or for the repair, decline and put your refusal in writing. Reference your workmanship warranty and, if relevant, MIS-3002.

If they acknowledge the fault but quote a significant delay for the repair, ask them to confirm the timeframe in writing. Unreasonable delays (several weeks in wet weather) may themselves constitute a breach of contract.

Escalation path

If the installer disputes the cause, ignores your emails, or refuses to attend, you have several escalation routes. Work through them in order:

1. Formal written complaint to the installer. If your emails have not produced results, send a formal letter of complaint (by post and email) to the company director or registered address. Give a clear deadline — fourteen days is reasonable — for a written response.

2. MCS complaints process. If the installer holds MCS certification, you can raise a complaint directly with MCS. MCS has the power to investigate member installers and can require them to rectify defective work. Details are on the MCS website.

3. RECC (Renewable Energy Consumer Code). If the installer is a RECC member — many MCS installers are — RECC offers a dispute resolution service. RECC membership requires installers to follow their consumer code, which includes honouring warranties and responding to complaints promptly.

4. IBG provider. If the installer has gone bust or is simply non-responsive after formal escalation, contact your Insurance-Backed Guarantee provider directly. Your IBG certificate (issued at installation) will name the provider and include a claims number.

5. Your buildings insurance. If the water damage is significant and the installer will not act, contact your buildings insurer. Explain that the damage was caused by a third-party contractor's defective workmanship. Your insurer should cover the remediation and may then pursue the installer through subrogation — meaning they recover their costs from the installer's liability insurer, not from you.

6. Small claims court. As a last resort, a County Court claim for the cost of repair and any resulting damage is a viable option for amounts up to £10,000. A documented paper trail — your installation contract, the emails, your photos, any written responses from the installer — is the foundation of this claim.

Can a roofer fix it?

A roofer can usefully assess the extent of the water damage, identify cracked or missing tiles from outside, and advise on the condition of the flashing and felt. This assessment can be helpful evidence in a dispute with the installer.

However, if the leak is caused by the mounting system — incorrectly seated hooks, poor sealant at cable penetrations, wrong hook type — a roofer alone cannot resolve it. The panels will need to be temporarily removed and the mounting system inspected and refitted by someone with solar installation competency. A roofer is not trained or insured for DC electrical work.

The practical approach: if you need an independent assessment to support your complaint, a roofer can provide that. But the actual fix will require the solar installer's involvement, ideally under warranty.

Prevention: the installation day checklist

Most roof leaks caused by solar installations are preventable. They result from workmanship shortcuts — hooks not fully seated, cracked tiles not replaced, cable entries not sealed properly — that a thorough check on installation day would catch.

If you have not yet had your system installed, or if you are booking a second system, the installation day checklist covers exactly what to look for before the installer leaves site: tile alignment, loft space inspection, sealant quality, and commissioning checks. Getting into the loft on the day of installation takes ten minutes and can prevent months of dispute.

Insurance and financial recovery

If the water damage is already done and the installer will not act, your buildings insurance is not a last resort to be embarrassed about — it is what buildings insurance is for.

When you contact your insurer, be clear that the damage was caused by a third party's defective workmanship, not by storm damage or an existing defect. Most buildings policies cover sudden water damage from an identifiable cause. Your insurer will likely send a loss adjuster to assess the damage.

Once your insurer pays out, they are entitled to pursue the installer's public liability insurance for recovery — this is called subrogation. You do not have to manage that process yourself. The insurer takes over the legal pursuit while you get your home repaired.

Keep all your correspondence with the installer safe. If your insurer pursues a subrogation claim, your paper trail directly supports their case.

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