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The Importance Of Cleaning & Maintaining Exterior Timber Cladding

10 minutes
August 25th, 2020

External timber cladding has continued to be extremely popular over the years with architects and designers due to its many benefits such as aesthetically pleasing features, impressive durability and adding texture to the environment. However, it still requires some maintenance and cleaning, which can be tricky when issues arise during a project.

This guide will provide you with all the information you need to know when it comes to cleaning and maintaining your timber cladding.

How To Clean Timber Cladding

Apart from regular cleaning to ensure your timber cladding retains its beautiful and stunning appearance, you will need to do a thorough clean when you are re-staining or recoating the timber.

One of the most effective ways to clean your cladding is with a timber cleaning product such as Intergrain UltraPrep Timber Cleaner, which is designed to remove stubborn contaminants including dirt, stains, mould, tannins, oils and mildew. Specialist timber cleaning products can also help with removing any grey timber, which are old timber fibres that occur as it weathers over time.

For external timber cladding, using a pressure washer is a great way for keeping the timber clean because it will remove grime and dirt without causing damage to the wood’s coating. Although, it’s always better to hire a professional to ensure you are getting the best results.

How To Treat Timber Cladding

To ensure you aren’t having to constantly clean your timber cladding, it is also extremely important to maintain it. As keeping the timber dry is crucial to maintaining its durability, it’s essential to use a leading timber coating product. When choosing a timber coating, especially for exterior cladding, always make sure it’s a protective coating that is UV and water-resistant.

Depending on the instructions of your timber coating product, the typical steps of treating timber with a saturating wood oil are:

  • Firstly, making sure that the timber is dry.
  • Using a brush, sprayer or roller, apply the first layer of coating.
  • Wait between 15 and 30 minutes so the timber can absorb the coating, ensuring that the second coating doesn’t penetrate the wood.
  • Apply the second coating and then wait 15 to 30 minutes.
  • Repeat this process until you notice that the wood isn’t absorbing any more of the coating.
  • Rub, wipe or brush off any excess coating so there are no ‘shiny spots’.

How Often Do You Need To Maintain Timber Cladding?

Depending on the type of timber you are using, its application and the type of timber coating you used, the maintenance period could be anywhere between 1 and 5 years. It’s best to create your own maintenance cycle using a calendar so you can keep track of inspecting the timber cladding.

Mistakes To Avoid

Whether you’re cleaning, maintaining or choosing the timber for your cladding, here are some important yet common mistakes to avoid:

  • Always choose a cladding made from hardwood as it is more durable than softwood.
  • Try to avoid installing timber cladding during a heatwave, as this can cause curling or warping of freshly cut timber.
  • Be sure to handle any pre-finished timber with care to avoid any scratches on the surface.
  • When stacking groove and tongue profiled timber boards on-site, make sure that the timber isn’t stacked in direct contact with the ground and stacked wide side spacing.

However, have you ever had dark spots appear on your timber cladding during installation? Or maybe you’ve noticed some stains or marks after installation?

Why Do Dark Spots Occur?

Timber cladding is often installed into metal battens or in conjunction with aluminium window installations, which in turn produce metal shavings. When metal shavings are exposed to wet, blonde coloured timber, they will oxidise and result in dark spots in the space of 24 hours.

To demonstrate, we conducted an experiment of our own:

These dark spots can be wrongfully mistaken as mould – which is essentially impossible in IronAsh treated cladding. For example, IronAsh timber cladding is treated for decay and termites and cannot develop mould in such a short space of time.

How To Fix Dark Spots

The good news is that it’s an easy fix. Intergrain has created a product to clean the dark spots completely off!

Simply apply Intergrain UltraPrep Timber Cleaner to the affected areas and the timber cladding will be as good as new.

The Intergrain UltraPrep Timber Cleaner is a high strength cleaner that contains naturally occurring, bio-degradable organic acids that will help restore and prepare weathered, grey, dark spots, rust or tannin-stained affected timber.

Hot tip: to prevent any spotting, correctly store and protect the cladding from weather and keep wrapped as required until installation.

So there you have it, an easy fix to a simple problem!


Find out more about Intergrain’s UltraPrep or why our IronAsh timber is the best option for cladding.