Rainline Maintenance of Painted Steel

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  • Rainline Maintenance Instructions for Painted Steel
  • Maintenance Instructions for Painted Steel
  • Painted Steel Maintenance Instructions

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Lindab Coated Steel Metal Maintenance Instructions

These maintenance instructions are for Lindab products manufactured of painted sheet metal such as Lindab Rainwater Systems, Lindab profiled sheets for cladding or roofs or Lindab façade cassettes.

Regular cleaning of roof and wall surfaces is an important aspect of the maintenance of Lindab paint coating. To ensure the Lindab product is sustainable in the long-term any damage to the surface coating must be repaired.

Painted building components from Lindab should be regularly inspected:

Initial Inspection

All loose objects should be removed from roof surfaces, rainwater systems or edges of façade cassettes immediately after installation, such as:

  • ​brackets
  • pieces of sheeting
  • drilling swarf
  • other metal objects

Visual Inspection

Every year a general inspection of the paint coating should be carried out. The Lindab coating should be visually inspected from a distance of around 1.5m.

The condition of the coating should be inspected not forgetting angles and eaves. Signs the paint coating needs to be repaired:

  • Flaking paint
  • Unevenly bleached paint surfaces
  • Chalking
  • Cracking
  • Scratches

Keep Clean

Rubbish and dirt entail a risk of corrosion as they can keep Lindab sheet metal damp. Ensure Lindab walls, roof and rainwater system are clean.


Rain is usually sufficient to keep Lindab sheeting clean. Any deposits of dirt that the rain does not rinse away can be washed off with a soft brush and water.  Surfaces in the "rain shadow", i.e. where the rain is unable to rinse off the sheeting, need particular care.

A detergent solution may be required to get the sheeting clean in areas with polluted air.  Normal dish washing liquid or industrial detergent can be used.

Rinse off carefully afterwards.

* Use according to the manufacturer's recommendations.

Cleaning Advice:

  • Damage to the paint can be caused by stronger solutions than those which are recommended.
  • Rinse thoroughly to ensure all detergent residues are removed.
  • Organic solvents and abrasive detergents should be avoided.
  • Apply the cleaning agent and rinse from the top down.
  • Work carefully.

Touching Up

Touch up repairing is possible if the paint layer has few and small areas of damage. Only paint in the areas that have been damaged using a narrow brush and an air-drying paint. It is important to only paint where required as the touch up paint is expected to age differently over time to the factory applied paint.

Treat Corrosion Damage

1. Any loose organic material should be scraped, sanded or sand blasted off.

2. Any rust should be removed through sandblasting or by sanding the sheet metal completely clean in the damaged area.

3. Clean with alkaline degreaser, for example 5% caustic soda with the addition of a little detergent.

Carefully rinse the surface with water and allow to dry. 

4. Paint with a zinc-rich undercoat.

5. Apply a suitable paint over this.

Treating Edge Corrosion

Edge corrosion does not usually occur in normal environments. Edge corrosion can occur in aggressive environments and should immediately be remedied in order to keep the sheeting intact and extend its lifetime.

Follow the ‘Treat Corrosion Damage’ steps and finish with a topcoat. In the case of edge corrosion, it is particularly important for the newly painted areas to enclose cut edges.

Edge corrosion on overlap jointed sheeting can be more difficult to treat due to the difficulty of the underside being accessed and cleaned. One solution to this is to seal the joints. Clean and remove loose material, then apply joint compound over the joint.

Tips to extend the aesthetic lifetime of Lindab coated steel metal:

  • Choose fastener and insulation materials that do not allow galvanic corrosion.
  • Design it to avoid standing water on the products.
  • Careful installation should be carried out preventing damage to the products.
  • Inspect the sheeting regularly.
  • Touch up damage to the outer surface immediately.
  • Rinse off sheeting that has not been rinsed by rainwater.
  • Clean guttering regularly.


Repainting of external sheeting should always be carried out professionally using a proven paint system.

Reasons for repainting sheeting:

  • Colour changes
  • Flaking
  • Corrosion
  • Wanting to change the colour

Tips for Painting Work

  • Sheet metal surfaces which are to be touched up or repainted should be dry and clean of dirt and grease.
  • Paints must be carefully mixed to reduce the risk of obtaining a deviating colour.
  • Do not paint in direct sunlight.
  • Do not paint at temperatures below +5°C for solvent based paints, or below +10°C for water-based paints.
  • The relative air humidity may not exceed 80 percent.
  • Check that old paint is properly attached!
  • Read the paint supplier's instructions.
  • Remove loose paint and other particles using a scraper and steel brush.
  • Surfaces with red rust must be carefully steel brushed or sandblasted.
  • Clean with alkaline degreaser, for example 5% caustic soda with the addition of a little detergent. Ideally use high-pressure washer.
  • Rinse with clean water and allow the sheeting to dry.
  • Choose a paint system depending on the surface and the cause of repainting.
  • Use a brush, roller or paint gun for the work.
  • Choose a narrow and soft brush when touching up small areas.​​

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