Housing company metal roof maintenance coating, Helsinki
Basic information
Location: Helsinki
Subject: Housing company's metal roof, approx. 30 years old
Project description: Maintenance coating of sheet metal roofs with NowoCoat and NowoMetal products
Quality Guarantee: 8 years
We carried out the maintenance coating of the sheet metal roof for Housing Company As. Oy Helsingin Rudolfinkuja 2a. The roof's 30-year-old plastic coating had worn down and no longer provided adequate protection for the metal – a heavy buildup of ingrained growth and some rust had accumulated on the surface, and the severely faded colour detracted from the appearance of the otherwise striking building. The condition survey revealed no significant damage to the metal sheeting or roof structures, so the condition of the roof could be fully restored with a thorough maintenance coating. The work restored the roof to a like-new appearance and extended its lifespan by an estimated 20–30 years – at a fraction of the cost of a roof replacement.
1. Security
The building, surrounding structures, vegetation and pathways were carefully protected before starting the work, so that the cleaning and coating agents did not reach unwanted surfaces and the work remained neat and safe throughout the project.
2. Washing and cleaning
The roof was first washed as clean as possible with a high-pressure washer intended for sheet metal roofs. After this, the surface was thoroughly brushed with NowoClean Metal Cleaner roof cleaning agent, which removed all remaining grease, dirt and impurities. The surface was rinsed with clean water and allowed to dry completely. A completely clean surface is a prerequisite for good and durable adhesion.
3. Mechanical cleaning and rust removal
All loose paint and rust were mechanically removed using a cup wire brush attached to an angle grinder. Cleaning was carried out in accordance with the international ISO 8501-1 standard to cleanliness grade St 2. The removal of rust and loose material is essential to ensure durable adhesion.
4. Rough grinding
All sheet metal surfaces were sanded with a random orbital sander to a uniform texture and matt finish. Careful roughening ensures that the coating adheres thoroughly to the metal and enables maximum bond strength.
5. Spot priming and rust protection
Bare metal areas and areas with previous rust were spot-primed with NowoCoat Special Primer anti-corrosion primer. Spot priming protects vulnerable areas against corrosion and ensures even adhesion of the paint system, even in critical areas.
6. First coat of paint
A thin layer of NowoMetal Roof 2-K PU Combi SB coating was spray-applied to the entire roof surface, with a dry film thickness of 30–40 µm. The thin primer layer ensures optimal adhesion to the substrate.
7. Second coat of paint
Once the base coat had cured, a second, thicker layer of the same coating was spray-applied to the roof, resulting in a total dry film thickness of at least 120 µm throughout. A sufficiently thick coating provides excellent wear resistance, UV protection and a long service life even in demanding weather conditions.
8. Final cleaning
All waste, protective coverings and materials generated during the work were removed, and the work area was carefully tidied. The site was handed over to the client in a clean and presentable condition.
9. Final inspection and project report
Once the work was completed, a thorough final inspection was carried out together with the client. A comprehensive project report was handed over to the client, documenting the stages of the work, the materials used, and maintenance instructions to ensure the longest possible service life for the surfaces.
Result
The metal roof was given an even, hard-wearing and weather-resistant surface. The thorough maintenance coating ensured optimal adhesion, corrosion protection and resistance to UV radiation and weather conditions. The maintenance interval was estimated at around 20–30 years under normal conditions, depending on the environment and upkeep.
The longest quality guarantee in the industry
The work was granted the painting industry's longest quality guarantee of eight years, which covers any potential defects and shortcomings arising from the execution of the work. Problems resulting from the work that appear during the guarantee period will be rectified promptly and at no additional cost to the customer.