Application note
RV Roof Mounting for Highway Wind Loads
Mounting solar panels to an RV roof is not a static engineering problem. The vehicle moves, and the array has to survive the airflow that comes with it.
The Challenge
Two factors dominate an RV roof installation: security and water leaks. Panels must withstand 200 km/h — 120 mph — winds while the vehicle is in motion, because driving at highway speeds with high headwinds or strong gusts subjects the panels to exactly those loads. All it takes is one short gust to break a panel off a weak mount.
Pain Points
- A single gust can tear a panel off an under-specified mount at highway speed
- Mounting points that leak turn a solar upgrade into a roof repair
- Sealant chosen for the wrong substrate fails at the first thermal cycle
- Every additional fixing point is another place for water to get in
What We Recommended
Step 1
Specify a mount rated for the load the vehicle actually generates, not for a static roof.
Step 2
Seal the mounts with a self-levelling caulking compound intended for RV roofs — Dicor is the product named for this, used on roof vents, TV antennas, solar panel mounts, air conditioning units and roof edges.
Step 3
Where possible, avoid the penetration altogether by bonding ABS mounts instead of drilling.
Step 4
Keep the number of fixing points to the minimum the module actually needs — four feet up to 85 W, six for larger rectangular modules.
Result
What Changed
An array that stays attached at motorway speed
Mounting points sealed with a compound designed for the roof material
Fewer penetrations, and therefore fewer things that can leak
A consistent method that can be repeated across a fleet
Products used
Hardware Referenced in This Note
BS09002Z Mount RV Solar Panel Mounts
Z-shaped aluminium feet for fixed-flat module installation on flat or curved RV roofs.
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BS09002-FKSolar Panel Flush Mount Kit
A boxed set of four aluminium feet that gives a discreet flush mount for one panel on an RV, caravan or camper.
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BS09003-FAluminium Solar Bracket 4 Pack
Four factory-anodised aluminium feet, 100 × 60 × 60 mm, pre-drilled and supplied with 316 stainless screws.
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BS09003-SAluminium Solar Bracket 6 Pack
Six anodised aluminium feet with 316 stainless screws, for larger panels that need mid-rail support.
View details →Questions
Frequently Asked Questions
What wind speed does an RV array have to survive?
200 km/h, or 120 mph, while the vehicle is in motion. Highway speeds combined with headwinds or gusts produce those loads.
What sealant is recommended for RV roof mounting points?
A self-levelling caulking compound meant for RV roofs. Dicor is named for this use — it is used on roof vents, TV antennas, solar panel mounts, air conditioning units and roof edges.
Is bonding an option instead?
Yes. On a caravan or motor home, Sikaflex 221 heavy duty bonding sealant lets our flush mount feet be attached with no hole through the roof at all.
A Similar Job to Quote?
Describe the vehicle or vessel, the panels and the roof construction. We will tell you what to order and what to bond it with.