As part of News Editor Conor Feasey’s deep dive into the thorny topic of teak in our recent Captains issue of  The Superyacht Report, he spoke with three of the top suppliers about the alternative deck materials that offer all the properties owners are looking for while being both ethical and sustainable.

Their responses are being published in three parts – here is the second; part I has already been published and the third will follow in the coming days.

Traceability and certification are clearly central to your operation. How are you navigating that alongside ongoing controversies with Myanmar teak?
Well, of course, it’s about sustainability, but it’s also about protecting ourselves. We have to be certain we’re using the right sources and certificates and that everything comes from legal sources. This is a key part of our business. If we make a mistake, it’s not just a minor problem – our company could get into trouble.

You still see misleading claims being made in the industry all the time. At trade shows, for example, we’ve witnessed teak dealers from China offering what they call “Chinese teak”. We would never purchase that kind of wood.

Shipyards are also in a new and uncertain situation and do not want to make mistakes. For example, one of our customers stopped working with us over a certain period for teak projects. They thought they’d found a new source with plantation teak, but the quality was not acceptable in our eyes; we said no, we cannot use this. So they stopped giving us teak orders, but we continued producing synthetic decks for them. There was a lot of uncertainty during that period. Nobody was sure what the right move was. Today this customer uses our FSC-certified plantation teak solution including proof of origin by isotope analysis.

So you are currently sourcing FSC-certified plantation teak. Do you see teak as still widely available globally?
Oh, most definitely. We’re sourcing FSC-certified plantation teak from Thailand and, in this case, traceability is very clear, you have complete documentation. This is something we’ve been working on for years and now, we’re starting to see the benefits. Shipyards want to protect themselves – they don’t want to take risks. If they’re unsure about quality or legality, they will not use solutions with teak wood. That’s where we can step in.

Teak is cultivated in virtually all tropical regions of the world. Due to the high price of wood, teak is one of the most widely reforested types of wood in the world. So the volume is there, but the issue is quality and education. If people aren’t managing the trees properly and trimming the branches correctly, you end up with a lot of knots. And then that wood becomes unsuitable for yacht decking.

You need to adapt around those inconsistencies in quality and size, with shorter planks and then connect them with scarf joints. That’s one way. Some manufacturers also use butt joints, although that’s technically not ideal, or use a traditional expansion joint like a Bostik or Sika flexible seam.

But you have to move away from the old idea that a teak deck has to be made from five-metre-long, flawless planks. That era is over. Even getting a three-metre plank that’s high quality is becoming difficult. Maybe it’s possible from some areas in Asia, but it’s rare.

Tesumo on board 74-metre Lürssen-built M/Y Global. Image credit: Image: Peter Seyfferth

Realistically, then, is there a case where plantation teak still makes sense?
You can make it work with projects using 45mm-wide planks, meaning a small, one-off project, say 150 to 200 square metres. By using this dimension you can minimise the loss in raw material. You can also cut it down if you have boards that are 105mm wide and only need 80mm, but then you’re creating a lot of waste. And that’s not sustainable either, so we do not use this kind of wood for one-off projects but only for semi-custom decks between 55 and 130 feet.

That’s why we’re very selective about our sources. We look closely at which customers can use plantation teak. For example, some of our customers use plantation teak from Middle America. For them, we found a good source. It’s not Brazil, as you might think, but Panama. With the right partner, you can find small but high-quality sources.

We tested it with the Johann Heinrich von Thünen-Institut in Germany, the German government’s main consultant body, and they said, ‘Protect these sources’. They hadn't expected such high-quality plantation teak from this area. They said it was almost comparable to Burmese teak in terms of durability. It’s FSC-certified, which is essential.

Of course, the FSC-certificate is not a carte blanche but it gives you a high level of security. This means another organisation checks the process, sets standards and verifies the wood is legally sourced. To go one step ahead, Wolz Nautic and their wood suppliers are undertaking additional isotope analysis of the containers which are shipped to Germany. 

“You have to move away from the old idea that a teak deck has to be made from five-metre-long, flawless planks. That era is over. Even getting a three-metre plank that’s high quality is becoming difficult.”

You’ve worked with a range of alternative materials. What can you tell me about the challenges you see with modified woods? Have you had any recent real-world tests with this?
There is currently no product on the market that is used on a large scale. Previous solutions have proven to be too error-prone. Too many planks have been cracked. The best solution currently on the market is Tesumo. It uses a three-step modification process.

You start with a light wood and put it into a kiln. You temper it to get that brown colour. In that process, the ingredients in the wood, like the sugar molecules, get burned. Then you use that treated wood and impregnate it with a mix of melamine resin and other ingredients. That gives it back some of the original stability and a similar appearance to teak.

Wolz Nautic successfully installed several Tesumo decks during the past years. Currently we are working on the 2,800sq-metre Tesumo deck of REV Ocean and as well as Project Zero. One of the latest Tesumo decks of around 160sq metres I saw last year in Cannes. It was still relatively fresh, about six months in the water then and it looked great. The client and crew are satisfied and I noted only some small issues which were solved very quickly. This is actually a serious alternative to teak and we believe in Tesumo.

The treatment uses vacuum pressure to impregnate the wood so that every cell is filled with resin. That includes the most minor holes or cavities, so the structure becomes quite solid again. Tesumo is a viable option, especially for big boats and superyachts. And that’s important because you simply won’t be able to find plantation teak of good enough quality in width over 45mm in the future.

Scarfed planks.

It’s not just about the type of wood, but how it is used in the application. One thing Wolz Nautic has become synonymous with is scarfing. So, how does it work and why does it matter in the context of the future of sustainable decking?
Scarfing is one option that is a more efficient way of laying a deck. It’s not new; it’s been done for many years. Usually, when you glue planks together, you use butt joints, but that’s not necessarily the best solution from a technical point of view or owners do not like it.

Some will glue two planks together without any expansion joint (butt joint); that’s a cheap solution and technically, it’s not right. Over time, there’s a risk that the glue line opens. If you do it properly, scarfing is much more expensive because it takes more work, but it’s the correct way. And after some time, even with teak or any other wood, it will go grey. When it does, the colours become more homogenous, and you no longer see the scarf lines.

But again, it’s more expensive. You must select the wood, cut it and fix it together correctly with the right pressure. Otherwise, the glue lines will open. And this is what we see in the market – many cheap glue lines that don’t last, and that’s not something we want to offer. We avoid that entirely because we know it will fail.

Roughly how much more expensive is it?
Between 30 and 60 per cent more, depending on the case. For a mass-production boat, you always have the same wood quality. You go to the warehouse and take what you need. But if you need to scarf together planks for a complete deck, you must look at everything. The grain, the colour, whether it matches or not. That takes time, especially in the pre-selection process.

Particularly in the areas the owners use most often, the wood must be selected carefully so that a nice result can be achieved. So it works with teak and it works with Tesumo, too, but it takes much more effort to do it properly.

“We can do more as an industry in so many ways. We’ve started a teak reforestation initiative in Thailand to use for future projects.”

From expanding sourcing networks to educating owners and applying materials properly at the build stage, it’s a long day’s work for suppliers. But do you think we are missing anything as a collective sector?
We can do more as an industry in so many ways. We’ve started a teak reforestation initiative in Thailand to use for future projects. We approached our partners and asked if we could begin replanting teak trees there. At first, they thought we were crazy. “Why are you doing this? It costs a lot of money.” But it’s just the right thing to do.

In these plantations, we’re harvesting selectively, not clear-cutting. The trees are allowed to grow for 25, 30, sometimes 35 years before being harvested. And again, only selected trees are cut. It doesn’t make sense to cut a tree that’s too small, too thin or poorly shaped because you can’t use that wood for decking. So it’s more sustainable to let them continue growing.

We started with just over two hectares and have planted around 1,500 seedlings so far. The trees need three to four years of maintenance, after which they can grow independently.

It’s not a massive investment either. It’s manageable and we plan to expand it. The important thing for us was to start somewhere. We need to think in terms of context. We harvest the wood and replant it there. Only in this way can we speak of value retention. The approach behind that is: ‘Your wood came from here. These are selected trees. And we are replanting for the future.’

This way, it becomes part of a bigger story. It could even work symbolically, a transition from our current CEO to his son, for example. Maybe in 35 years, the next generation will harvest the first trees from this new plantation. It’s a legacy and a message to our clients: this is responsible wood, grown with care, and is being replaced. We can show them the whole cycle where the wood comes from, how it’s grown and how we’re replacing what we take. Yes, we’re building for people, but in a world that deserves better.

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