The Storage Competitor Self Storage Park Construction Project

Dutch Greenroof – make self storage greener

We continue to actively seek opportunities to optimize the appearance and operation of our storage facilities. For example, we are constantly looking at new ways to heat containers and improve the overall indoor environment. You can read more about that in this article.

We tell nothing new when we state that our climate is quite erratic. Hence, we recently started looking at container cooling options. One possible solution is currently being actively tested at our demo park in Deventer: a greenroof. In addition to cooling, a green roof, also known as a sedum roof, naturally also offers opportunities for a container yard to blend in better with its immediate surroundings. In the process, it promotes biodiversity. Only advantages you might say. For the greenroofs, Universal Storage Containers has partnered with Dutch Greenroof of Holten, Overijssel. To learn more, we interviewed Rolph Markvoort, co-owner at Dutch Greenroof.

What is your position?

‘I am a business owner but actually do all sorts of things within the company. I’m mainly on the sales side. In addition, I deal with the nursery and procurement of nursery materials.’

What does your company do?

“We set up a company dedicated to growing products, such as sedum mats and cassettes, that can be applied to roofs.

Do you also install?

‘At Dutch Greenroof, we are growing sedum. So from the nursery we do not install. We do actively provide instructions to partners such as USC, for example, on how they themselves can install the sedum for their clients.’

What does sedum consist of?

‘Sedum is actually fatwort. There are several types of these. Sedum is very weather resistant and does not need much. That makes it the perfect plant for application to roofs.’

How is sedum grown?

‘That happens here in the open ground. We begin by spreading a layer of potting soil. Then we sow the planting material. Then it is a matter of waiting for it to mature. Meanwhile, we make sure there are as few weeds between them as possible. It takes on average between six and 12 months to grow a full mat, which also depends on the season.’

How did the contact with USC come about?

“That came about during a meeting of MKB Trade Office from Deventer, I met Jan-Hein there and was excited about his idea to work with sedum on their storage containers.”

What did you provide?

‘We provided a test cassette setup for USC for two container roofs. We chose cassettes because of the ease of installation. In fact, USC can now lay and possibly relocate sedum roofs itself. This keeps the setup flexible. Also, by using cassettes, the weight has been reduced.’

Have you supplied sedum for containers before?

‘Yes, but that was for container homes. This is similar in terms of laying out, but USC’s containers are for storage of goods and not for occupancy.

How is it laid out?

‘A normal green roof is constructed according to FLL guidelines. That includes: with a protective cover, drainage, substrate, a separation profile and sedum/vegetation layer. The difference with cassettes is that these are pre-grown and also arrive at the customer in cassettes. This second option is extra work for us, but so for USC it offers additional flexibility and ease of installation.

How might it affect the container climate?

‘Sedum roofs significantly reduce heat on roofs. However, it varies from roof to roof by how many degrees. I am therefore very curious about the test results at USC. “When those are known, we will know the exact difference.

Does the sedum require maintenance in terms of watering/weed removal?

Some maintenance is needed once or twice a year. This mainly means applying some extra fertilizer or removing weeds. Watering is actually not necessary because the sedum has enough with the humidity that is usually highest in the morning. In very dry climates, minimal watering from time to time is sufficient.’

How long can it last?

‘Basically forever. So sedum roofs are very sustainable products.

Will the project be evaluated?

‘The customer often does feedback the experience to us. USC, of course, also. We stay informed this way and make adjustments if necessary.

Want to know more about our experience with sedum roofs on self-storage containers? If so, please contact us at or +31 570 765 035

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