Warehouse Roof Leaks from Fog & Dew: Early Warning for UAE Warehouses
When Morning Fog and Dew Start Dripping Inside
Many warehouse owners in the UAE first notice leaks not during heavy rain, but on calm mornings after a night of heavy fog or dew. Staff arrive to find droplets falling from the roof sheets, wet patches on the floor, or damp cartons directly under roof joints and fasteners. Because the weather is clear, this is often dismissed as a minor nuisance.
In reality, if your roof is leaking from dew and condensation, it is a clear warning that the roof system has already lost its integrity. The small amount of moisture produced by fog and dew simply reveals the same pathways that will carry far larger volumes of water during a proper rainstorm.
⚠️ Dew Drips = Structural Warning
- Fog and dew produce only a thin film of water on the roof surface.
- If that tiny amount is already entering the building, the waterproofing and overlaps are compromised.
- When it rains, those same gaps will carry litres of water per hour into the warehouse.
Why Fog and Dew Reveal Hidden Roof Defects
Warehouse metal roofs are constantly cycling between hot days and cooler nights. In winter and during heavy fog, the roof sheets drop in temperature and moisture from the air condenses on the metal surface. This water collects along overlaps, screws, cut edges and any point where the sheet is not perfectly sealed.
If the original waterproofing, sealants, or fastener gaskets have aged, shrunk, or cracked, the condensed water will find its way through. The result is slow, persistent dripping that appears only in the early morning, then seems to vanish when the roof warms up again.
💧 Common Causes of Fog-Related Leaks
- Old or cracked sealant along roof overlaps and flashing details
- Washer failure at fasteners and self-drilling screws
- Movement of metal sheets from thermal expansion and contraction
- Improper treatment of cut-outs, service penetrations, and roof lights
- Previous coatings that have become brittle or detached from the metal
Dew Leaks Today, Serious Rain Leaks Tomorrow
Dew leaks are rarely isolated. They indicate that water is already bypassing the protective layers that should be stopping it at the roof surface. During a UAE rain event, the volume and pressure of water on the roof is many times higher than during fog or dew.
When it rains, those same gaps that carry a few drops at dawn can become channels for continuous flow. This is when warehouses experience:
- Streams of water running along purlins and beams
- Water tracking to unexpected locations far from the visible defect
- Damage to stored goods, packaging, and equipment
- Slippery conditions on warehouse floors and safety risks for staff
- Corrosion of steel structures and electrical components over time
How RainSafe Fixes Fog, Dew and Rain Leaks at the Source
RainSafe specializes in long-term waterproofing systems for warehouse metal roofs across the UAE. Instead of chasing individual drip points with sealant, we treat the roof as a complete system and eliminate the underlying causes of condensation and rainwater ingress.
1. Detailed Roof Inspection
We walk the full roof, inspect overlaps, fasteners, penetrations, gutters and existing coatings, and identify how water is entering the building under fog, dew and rain conditions.
2. Localized Repairs & Preparation
Damaged sheets, loose fasteners, failed sealants and rusted areas are repaired or replaced. Critical details are reinforced so the roof structure is ready to receive a seamless waterproofing system.
3. Seamless Polyurethane Waterproofing
We apply a liquid-applied Saint-Gobain polyurethane system that forms a continuous membrane over the metal roof. This eliminates joints and micro-gaps where condensed water and rain used to penetrate.
4. Optional Cool Roof Finish
An optional high SRI (Solar Reflective Index) top coat keeps the roof surface cooler, reducing thermal movement, lowering AC loads in cooled warehouses, and improving comfort in non-air-conditioned facilities.
What to Do if You See Morning Drips in Your Warehouse
If you notice water dripping from your warehouse roof on foggy or dewy mornings, treat it as a maintenance priority. The problem is unlikely to disappear on its own and usually gets worse with each season.
- Document where and when the drips occur (time of day, weather conditions, approximate locations).
- Check for visible stains on purlins, beams and insulation that indicate repeated moisture exposure.
- Avoid placing sensitive goods directly under known drip areas until the issue is resolved.
- Arrange a professional roof assessment to understand the real extent of the problem.
Protect Your Warehouse Before the Next Rainstorm
Fog and dew leaks are the roof's early warning system. If you are already seeing drips, rain will only make it worse. RainSafe can assess your warehouse, identify the real causes, and design a long-term waterproofing system that protects your stock, staff and structure.
Schedule Warehouse Roof Assessment