Start at the roof, not the bucket
Two white coatings can look almost the same in photos and yet technically differ greatly. Existing roof covering, residual moisture, adhesion, slope, penetrations and movement determine which technology is promising.
An initial selection should therefore record what must be preserved, which zones require repair and which performances are demonstrably necessary. Only then is a comparison between polyurea, silicone, PU or acrylic useful.
- Substrate and existing layers
- Moisture condition and insulation
- Puddle formation and slope
- Details and expected movement
- Foot traffic and maintenance
- Desired renovation duration
What distinguishes a 2K polyurea system
A cold-applied 2K polyurea membrane is created by controlled mixing of two components. PolyShield processes this as a complete renovation build-up: preparation, substrate-specific primer, detail treatment and a continuous white UV-resistant membrane.
This route is interesting when mechanical resistance, crack bridging, walkability and a documented layer structure weigh heavily. This does not automatically make the system suitable: mixing ratio, processing time, layer thickness and environmental conditions require professional control.
- Primer is part of the selection
- Dealing with details before the main plane
- Register consumption and conditions
- Only claim achievements that match the chosen structure
Where silicone can be strong
Specialized silicone roof membranes are often chosen for their UV resistance, elasticity and suitability for water-stressed roofs. Some systems are single-component and react with humidity, which can simplify logistics.
Even with silicone, cleaning, adhesion, primer selection, detailing, layer thickness and maintenance remain essential. The assumption that a silicone coating can always be applied to any surface without a primer is technically too general. Consult the substrate table and official system documentation of the relevant variant.
- Check adhesion to existing roof layers
- Compare mechanical and walkable performance
- Request initial and outdated reflectance values
- Record repair and maintenance method
Compare reflection without energy promises
Solar reflectance indicates which part of the solar radiation is reflected back. Thermal emission describes how the surface releases absorbed heat. The Solar Reflectance Index combines both properties into a comparison value.
These values describe the surface under test conditions. They do not independently predict how many degrees cooler a building will become or how much energy will be saved. Insulation, ventilation, internal heat load, building shape, climate, pollution and aging influence the actual effect.
- Ask for test method and color variant
- Distinguish between initial and outdated value
- Check maintenance and contamination risk
- Have energy gains assessed separately when they are decisive
Compare the complete system
A low price per kilogram says little about the total renovation. Compare required preparation, primer, detail work, consumption, number of coats, execution window, curing, running load, repairability and documentation.
For an owner or manager, it is especially important what remains controllable later: moisture and adhesion research, quantity used, weather conditions, detailed photos, delivery points and maintenance advice.
- Total system structure and layer thickness
- Time to rain resistance and use
- Application limits for puddle formation
- Certificates and test reports
- Inspection and maintenance plan
When PolyShield preselects 2K polyurea
We mainly investigate 2K polyurea for larger commercial roofs where a stable existing structure can be maintained and where a mechanically robust, quickly organisable renovation route adds value.
If moisture, loose layers, structural defects or non-repairable details are found, we first recommend further investigation, partial replacement or another system route. An honest negative advice is part of professional roof management.
- Stable, technically suitable existing roof structure
- Accessible and durably repairable details
- Business need for limited disruption
- Wish for a white waterproof final membrane
- Project-specific documentation and delivery control
This explanation is general and does not constitute project-specific system advice. Subsurface investigation, tax and official system documentation remain decisive.