Do I have to maintain Shou Sugi Ban timber cladding?

Do I have to maintain Shou Sugi Ban timber cladding, if so, how much maintenance is required?

Myth: Shou Sugi Ban does not need any maintenance.

Reality: Any timber exposed to the weather will need maintenance at some point. The good news is that Shou Sugi Ban timber cladding or charred timber does last longer without maintenance than non-charred timber.

As manufacturers of Shou Sugi Ban cladding, we have tested this product before bringing it to market and here is what we found:

  • Timber species char differently depending on their density. Harder timbers like Spotted Gum take longer to char and have a thinner char layer. If you char Spotted Gum for too long the timber begins to warp. Softer timbers like Burnt Ash char much quicker creating a thicker char layer.
  • Timbers that are too soft like pine and cedar can char too quickly meaning they become brittle and the charred layer breaks off easily.

Now back to the question: Do I have to maintain Shou Sugi Ban Timber Cladding, if so, how much maintenance is required?

The carbon layer created on the surface of the timber is thicker than normal timber coatings and oils (the reason it lasts longer than non-charred oiled timber). The thicker the char layer the longer it lasts. It is a balance between charring the timber for maximize performance and not charring it too much causing splitting and a surface that is too soft.

We offer three timber species options for Shou Sugi Ban as standard, whilst we are not limited to these options, we have had the most success with these:

Burnt Ash Shou Sugi Ban

Burnt Ash is a thermally modified American White Ash. The thermal modification process increases the durability of American White Ash which means it is suitable for external use. Once thermally modified we call it Burnt Ash.

As Burnt Ash is extremely stable and has a medium density it is the perfect timber for Shou Sugi Ban Cladding. It offers the right depth of char and requires the least amount of maintenance of our three options.

Burnt Ash Shou Sugi Ban cladding is supplied with a factory coat of oil prior delivery. Once the cladding is installed, we recommend a 2nd coat oil is applied and a 3rd coat when the project is completed. The 2nd and 3rd coats need to be spaced 4-6 weeks apart to allow the oil to soak into the timber.

Whilst a maintenance coat is recommended every 3 years, Burnt Ash can last up to 4-5 years without maintenance coats depending on the level of exposure to the weather and the location of the project.

Jarrah Shou Sugi Ban

Jarrah is a medium density timber which provides an excellent charred surface. As Jarrah is not as stable as Burnt Ash the char layer is not quite as deep as Burnt Ash and does require extra maintenance. Jarrah is a good all-round option as it offers great value for money and it also meets BAL 19 fire rating.

Jarrah Shou Sugi Ban cladding is supplied with a factory coat of oil prior delivery. Once the cladding is installed, we recommend a 2nd coat oil is applied and a 3rd coat when project is completed. The 2nd and 3rd coats need to be spaced 4-6 weeks apart to allow the oil to soak into the timber.

Whilst a maintenance coat is recommended every 2 years, Jarrah can last up to 3-4 years without maintenance coats depending on the level of exposure to the weather and the location of the project.

Spotted Gum Shou Sugi Ban

Spotted Gum is a high-density timber which means the charred surface is not as deep as Jarrah or Burnt Ash. Spotted Gum is mainly used where the project requires BAL 29 timber cladding.

Spotted Gum Shou Sugi Ban cladding is supplied with a factory coat of oil prior delivery. Once the cladding is installed, we recommend a 2nd coat oil is applied and a 3rd coat when project is completed. The 2nd and 3rd coats need to be spaced 4-6 weeks apart to allow the oil to soak into the timber.

Whilst a maintenance coat is recommended every 2 years, Spotted Gum can last up to 3 years without maintenance coats depending on the level of exposure to the weather and the location of the project.

Shou Sugi Ban Comparison

1jarrah-shou-sugi-ban-fine-sawnspotted-gum-shou-sugi-ban
2Burnt Ash
Cost Guide: $$$
Density: 750 kg p/m2
BAL Rating: Non-BAL Rated
Maintenance: recommended 3 years, can last up to 5 years.
Jarrah
Cost: $
Density: 850 kg p/m2
BAL Rating: BAL 12.5 & 19
Maintenance: recommended 2 years, can last up to 4 years.
Spotted Gum
Cost: $$
Density: 1100 kg p/m2
BAL Rating: BAL 12.5, 19 & 29
Maintenance: recommended 2 years, can last up to 3 years.
Shou Sugi Ban Comparison Table

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