Beading

Weatherproof coatings for soft top roofs are hydrophobic and repel water, causing water droplets to bead up and roll off the roof. However, this only happens for a short while after the roof is re-proofed as dust soon collects on the roof which breaks the surface tension of the droplets. Water will then sheet and soak through the hood. 

What it means

Beading is the pattern you see when water lands on a well protected surface and pulls itself into little rounded droplets instead of spreading out. On cars it shows up on paintwork, glass, wheels and sometimes fabric roofs after rain or rinsing. Tight, round beads are a sign that the surface has a hydrophobic (water-repellent) layer from wax, sealant, ceramic or fabric proofer. On an unprotected or tired surface, water tends to sit flat, soak in or form large, lazy blobs instead.

Why it matters

• Quick sign of protection: Strong beading usually means there is some kind of protective product present and still working, even if you do not remember exactly what was applied.
• Helps the car stay cleaner: On a beading surface, much of the dirt is carried away as water runs or blows off, so traffic film and grime do not stick as firmly.
• Makes washing and drying easier: Water sheets and beads away more readily, so you spend less time chasing standing water and the risk of water spots is reduced.
• Useful for checking roof proofing: On a fabric soft top, fresh proofing often shows as neat beading and quick run-off. When beading fades and the roof drinks water, it is usually time to clean and reproof.

Where you’ll see it

You will see beading mentioned in detailing write-ups, coating brochures and inspection notes. Common phrases include strong beading on paint, beading effect faded, now sheeting or roof now beading nicely after proofing. Enthusiasts often photograph beading on bonnets, roofs and glass as a way of showing off fresh wax, sealant or ceramic coatings. On convertible roofs, you will see beading discussed when comparing different fabric proofers and roof treatments.

Context

Beading is one visible part of how a protection system behaves, but it is not the whole story. A cheap spray sealant can produce very strong beading at first then fade in weeks, while a durable ceramic coating may keep useful protection even after the beading softens. Different products are tuned to give either tight beading or more sheeting, where water runs off in larger sheets. On soft tops, very dramatic beading looks impressive, but long term protection still depends on the underlying roof construction and membrane as well as regular cleaning and sensible proofing.

Common mistakes

• Judging protection only by how well a surface beads, when some coatings can still be protecting even after the visible beading has reduced.
• Assuming all beading is the same, ignoring the big difference in durability between a quick-detail spray and a properly applied ceramic coating.
• Chasing perfect beading by constantly layering products, which can lead to product build-up and unpredictable behaviour instead of a simple, well maintained protection system.
• Forgetting that even strong beading does not make a surface scratch-proof - good wash technique is still needed to avoid swirl marks and marring.

Written by Danny Argent. Last updated 04/12/2025 03:54