Preservation conditions
The load-bearing substrate and existing roof layer must be sufficiently stable. Loose parts, contamination, plasticizers, previous coatings and moisture can affect the adhesion.
An inspection also looks at drains, bilges, upstands, penetrations and transition zones. It is precisely these details that often cause leakage while the main surface still looks reasonable.
- Sufficient coherence
- No uncontrolled moisture
- Cleanable surface
- Recoverable details
- Appropriate drainage
Signals that require additional research
Many bubbles, soft areas, prolonged water, recurring leaks or large height differences can indicate problems under the visible layer. Coating should not hide such causes.
Moisture measurement, test adhesion or a local roof opening may be necessary before a system proposal is justified.
From roof measurement to pre-selection
An aerial photo measurement determines the indicative surface area and helps delineate roof surfaces. Photos of details and damage add information, but do not replace the physical assessment.
For PolyShield, an indicative minimum size of 50 m² applies to private coating projects. Even above that limit, technical suitability remains decisive.
- Measure all roof surfaces
- Photograph drains and curbs
- Note leaks and puddle formation
- Describe accessibility
- Mention age and repairs
This explanation is general and does not constitute project-specific system advice. Subsurface investigation, tax and official system documentation remain decisive.