Protecting your solar panels from roof paint is all about preparation — get the masking and sheeting right before you open a single tin, and you'll avoid a costly, frustrating clean-up. Paint overspray and drips on solar panels can reduce their efficiency and may void your panel warranty, so it's worth taking the time to do this properly.
Why Paint on Solar Panels Is a Real Problem
Solar panels work by allowing sunlight to pass through a tempered glass surface onto photovoltaic cells beneath. Even a thin film of paint or primer can reduce light transmission and drop your system's output. Worse, some roof paints — particularly solvent-based or bituminous coatings — can chemically etch or permanently stain the glass if left to cure. Check your panel manufacturer's warranty documentation, as paint contamination may be listed as an exclusion.
Plan Your Job Around the Panels
Before you pick up a brush or roller, walk the roof and map out where your panels sit in relation to the areas you need to paint. Consider:
- Wind direction — even on a calm day, spray from a pressure washer or airless sprayer can travel several metres. Paint on a still day and avoid spraying directly upwind of panels.
- Roof pitch and run-off direction — on a steep roof, wet paint can run quickly. Work from the ridge down, and finish sections away from panels before moving closer.
- Access and safety — working on a roof is high-risk. Always use appropriate fall protection. WorkSafe NZ has clear guidance on working at height safely.
How to Mask and Cover Solar Panels
This is the most important step. Do it thoroughly and you'll have no worries.
Materials You'll Need
- Heavy-duty plastic sheeting or purpose-made drop cloths (at least 100 micron)
- Low-tack masking tape or painter's tape rated for exterior use
- Foam pool noodles or pipe lagging (optional, to protect panel edges from tape adhesive)
- Bungee cords or cable ties to secure sheeting in wind
Step-by-Step Masking Process
- Clean the panel frames first. Tape sticks better to clean surfaces, and you'll be able to see the edges clearly.
- Apply low-tack tape around the perimeter of each panel frame. Avoid sticking tape directly to the glass surface — use the aluminium frame only. Standard masking tape can leave adhesive residue on glass in warm weather.
- Lay plastic sheeting over the panels and tuck the edges under the tape seal. Overlap sheets by at least 200 mm if you need more than one piece.
- Secure the sheeting with bungee cords looped around the panel mounting rails, or weight the edges with offcuts of timber. Don't rely on tape alone to hold sheeting in a breeze.
- Check the seal by running your hand around all edges. Any gap is a potential entry point for drips or overspray.
- Remove sheeting promptly once paint in that area is touch-dry — don't leave plastic on panels in direct sun for extended periods, as heat can build up underneath.
Choosing the Right Application Method
How you apply the paint matters as much as how you mask.
| Method | Drip/Overspray Risk | Best Practice Near Panels |
|---|---|---|
| Brush | Low | Good for cutting in around panel edges |
| Roller | Low–Medium | Use short-nap roller, avoid overloading |
| Airless sprayer | High | Mask thoroughly; avoid spraying directly toward panels |
| Pressure-fed spray | Very High | Not recommended within 2 m of panels without full enclosure |
If you're using a sprayer, reduce the pressure and use a narrower fan pattern when working near panels. Many professional roof painters switch to a brush or roller for the sections immediately adjacent to solar arrays.
Dealing with Accidental Drips
If paint does land on a panel, act quickly:
- Water-based (acrylic) paint — wipe off immediately with a damp cloth while still wet. Once dry, a plastic scraper and warm soapy water usually removes it without scratching the glass.
- Solvent-based or bituminous paint — do not use solvents on panel glass without checking with your panel manufacturer first, as some coatings can damage anti-reflective treatments. Contact your installer or the panel brand's NZ distributor for advice.
- Cured paint — this is much harder to remove. A specialist solar panel cleaning service may be needed. Avoid abrasive pads.
Roof Paint Products and NZ Conditions
NZ's UV levels are among the highest in the world, so quality roof paint matters. Resene and Wattyl both offer roof coating systems suited to NZ conditions, including products for concrete tiles, Colorsteel, and Zincalume. Always follow the manufacturer's data sheet for application temperatures and recoat times — painting in the heat of the day can cause paint to skin over quickly and increase drip risk.
When to Call a Professional
Roof painting is physically demanding and genuinely dangerous work. If your roof is steep (over 25°), wet, mossy, or you're not confident working at height, please engage a qualified roof painter. A professional will have the right fall-arrest equipment, experience masking around solar arrays, and knowledge of which products suit your roofing material.
Solar panel installation and any electrical connections to your system are restricted electrical work under the Electricity Act and must only be carried out by a registered electrician. If panels need to be temporarily disconnected or moved to allow roof work, contact your installer — do not attempt this yourself. Check the Electrical Workers Registration Board (EWRB) to verify a tradesperson's registration.
You can find experienced, local roof painters on tradedirectory.co.nz who are familiar with working around solar installations.
Master Painters NZ member
Licensed Building Practitioner (LBP)
Roofing Association of NZ (RANZ)
