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By Appointment to Her Majesty The Queen Manufacturers of Wood Finishes Morrells Wood Finishes Ltd Stockport

omnia® Maintenance

Exterior Joinery Maintenance Guide

Whilst timber coating systems are guaranteed to last many years in an exterior environment, certain considerations must be made to ensure joinery remains in a sound state. The natural beauty of timber as a material for Exterior Joinery means that, if maintenance is carried out regularly, it will retain its visual appeal for a lifetime.

It is important to remember that regular, minimal maintenance will make recoating / re-decorating joinery a far easier job and as such, Morrells have compiled an easy to follow maintenance plan. 

Points to note

Mould and Algae

Whilst mould and algae pose little initial threat to the coating other than the aesthetic appearance, prolonged contact can have a detrimental effect on the coatings surface and lead to water absorption issues over time.

Whilst soapy water may work for early mould attacks, a wipe with a solution of one part bleach to five parts water should be enough to remove most stains. If the discolouration persists then use of a nylon bristled brush (Not metallic) can be used to remove the more stubborn stains.

Damage

Areas where the coating has been damaged or more severely eroded to the point where bare timber is exposed, action must be taken immediately as this exposure will get progressively worse and will lead to extensive maintenance/re-decoration in the future if left unattended.

Scheduled Maintenance

Timber whose orientation is north facing and is predominantly sheltered will generally require less maintenance than south facing timber on window sills or beads. As a general note, any repairs should be carried out as and when necessary.

Monthly

Inspect the joinery for changes due to the natural settling and seasoning processes. A general rinsing or cleaning process is likely to be all that is required to maintain the freshly manufactured appearance. See Cleaning and Washing cycle section below.

Annually

Inspect the joinery for changes. If areas are seen where the coating has lost its lustre or aesthetic appearance then a more intense cleaning/washing cycle would be recommended. See Cleaning and Washing cycle section below. 

Every three to five years

The application of a maintenance coating is often recommended on a 3–5 year cycle (or as needed) for exterior joinery since many factors, such as the joinery’s orientation, can influence the life expectancy of a coated timber system. See reapplying coatings/redecoration section below. 

Five years+

All products deteriorate over time and this is particularly true of those that are exposed to the elements. Wind, rain, sunlight, mould spores and general grime all contribute to the breakdown and deterioration of all materials. It is therefore important at this stage to maintain the system by increasing this barrier between the wood and the elements through the introduction of a maintenance coating. See reapplying coatings/redecoration section below.

A suggested recoat/maintenance coating table is shown in Table 1, however, in practice, carrying out the first redecoration approximately one year before the recommended time will significantly improve the longevity of the coating system. By using this table, the redecoration period for each face can therefore be evaluated.

Recommended Actions

Cleaning and washing cycle

Wash with hot water and liquid detergent every 6 months. Rinse with clean water. During this process it is advisable to inspect all components of the window for defects and to take action if necessary.

Reapplying coatings – redecoration

Remove any loose coating material from the affected areas and gently abrade with a medium grade of sandpaper (240 grit or higher), taking care to sand in the direction of the grain. Ensure that any grey timber that has been damaged by ultraviolet light is removed back to a clean, bright surface.

In DRY weather, brush apply a single coat of omnia® Clear or Colour using a synthetic bristle brush to the abraded areas, ensuring that any areas of end grain are sufficiently coated with End Grain Sealer. Allow the coating material to dry. 

See photos for recoat schedule.

 

Photos

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Usage

omnia® has been designed as a full finishing system, from surface preparation to topcoat. As omnia® is available in clear and opaque topcoat systems for multiple varieties of wood, please consult our Exterior Joinery Guide for Exterior Finishing and the system guidelines below. Choose your system below:

Ensure that the substrate is clean, dry and free from contaminants. 

Wipe all surfaces with a sharp solvent such as Morrells Cellulose Thinner (2007/000) prior to coating application. Turn the wiper so that the contamination is removed rather than dispersed. Allow the solvent to flash off for 30 minutes and apply the first surface coating within two hours of cleaning. Observe Health and Safety matters. The maximum recommended wood moisture content is 18%. We do not recommend the use of American Oak due its low moisture content and therefore liability of movement.

Clear Finishes:

  1. If knots are present and require sealing, brush apply one coat of omnia® Knotting over the knots only.
  2. Apply one coat of omnia® Protect in its clear form or in the appropriate colour. Ideally applied by dipping or flow coating but if brushed or sprayed, ensure that the surface is fully wetted so that the timber absorbs the product. The system is designed such that any stain colour can be obtained by the application of tinted omnia® Protect. However, for special requirements, the topcoat can also be tinted by our Fastmatch® colour-matching facility.
  3. Seal all end grain with one coat of brush applied omnia® End Grain Sealer (8ES/000) and allow to fully dry before denibbing the End Grain Sealer only. If the joinery will exposed to excessively to water or moisture, an additional coat is recommended.
  4. Apply the first coat of omnia® Clear to a wet film thickness of 150 -175μm.
  5. Lightly denib prior to the application of the final coat, using a synthetic sanding pad (Scotchbrite or similar).
  6. Apply the second coat of omnia® Clear to a wet film thickness of 150 -175μm.

Ensure that the substrate is clean and dry.

Wipe all surfaces with a sharp solvent such as Morrells Cellulose Thinner (2007/000) prior to coating application. Turn the wiper so that the contamination is removed rather than dispersed. Allow the solvent to flash off for 30 minutes and apply the first surface coating within two hours of cleaning. Observe Health and Safety matters. The maximum recommended wood moisture content is 18%. We do not recommend the use of American Oak due its low moisture content and therefore liability of movement.

Solid (Opaque) Colours:

  1. When coating non-durable timber, pre-treat with omnia® Protect.
  2. When coating red-brown woods, such as sapele, or other woods that may stain the coating, apply a coat of omnia Prime Pre-Treatment (8PT/000), a stain-inhibiting clear isolator. Ensure the surface is fully wetted so that the timber absorbs the product.
  3. Treat/seal all end grain with brush applied omnia End Grain Sealer (8ES/000); allow to fully dry before de-nibbing only the end grain sealer.
  4. Apply one coat of omnia Prime which is a stain inhibiting white Primer to a wet film thickness of 152μm. Apply two coats at 152μm each if severe staining is seen in the first coat.
  5. Apply the first coat of omnia Colour (Opaque Topcoat) to a wet film thickness of 150-175μm.
  6. Lightly denib prior to the application of the final coat using a synthetic sanding pad (Scotchbrite or similar).
  7. Apply the second coat of omnia Colour (Opaque Topcoat) to a wet film thickness of 150-175μm.