ASTL fastening system


Do you want to work more efficiently on your roof boarding and thereby limit the risk of the roof and inventory damage? Purchase our ASTL fastener for tapered insulation, it’s just a little investment. The patented product assures you of 7 damage-free years. We therefore strongly recommend it as a standard product for 3 types of roofing projects.

What is the ASTL fastener?

We developed it 7 years ago, with input from several Scandinavian partners. They needed a fastener for tapered insulation that secured their roof and inventory in all weather conditions. Their roofs had to be able to withstand the extreme weather conditions, without any damage to the roof, insulation layer or their inventory.

As the only one in the market, the ASTL fastener far exceeds the standard. Moreover, our product is still unique in its quality and efficiency. Ready for all circumstances that a roof has to endure.

We have developed a new, better slope closure. With the ASTL it is possible to bridge a difference of a maximum of 110 mm in the tapered insulation thickness with a combination of lengths. Moreover, it is very swift and efficient in processing on the roof.


In summary, the ASTL fastener stands for:

  • 100% step-security
  • 11 years of experience without damage.
  • Safety and securely installation
  • A bridge up to 120 mm. (application of ASTL-48-340/460)
  • Fast processing.

The system is therefore extremely suitable for fixing roof systems with tapered insulation on concrete. It makes the connection of concrete underlay, insulation layer and thus the entire system faultless - and therefore makes the result practically free of risk. You will not be able to break this security; not due to leakage, poor assembly or natural wear. Moreover, it might come in useful in the roofing of the following 3 types of roofs.

The advantage of ASTL with 3 types of roofing projects

The most important feature of the ASTL mounting combination is that it is good for bridging large differences in height. As a roofer or contractor, you can probably estimate the greatest benefit you have with this: you need fewer different fasteners in stock. It doesn’t only saves on purchase, it also saves a lot of hassle on the roof, in the 3 following scenarios:

1. With height difference in (tapered) insulation

As a roofer, you can encounter a typical problem when securing the roofing systems on roof floors when having differences in height in the concrete floor slabs..

You work with different heights: 10, 12, 13 and 15 centimetres for example. With a standard combination fastener (grommet with concrete screw) you have a maximum clearance of 1 centimetre. That means that you do need 4 combinations to bridge that slope. You need one combination in one place, and the other in the next. Also, that means a lot of different boxes, large order quantities, and much surplus at the end of a project. Not to mention the inefficient work on the roof, with a constant search for the right combination.

The ASTL automatically secures itself without much effort; you just have to screw in your combination. That way he can control a slope of 11 cm difference, automatically, so you can cover a complete roof (slope) with 1 or 2 ASTL fasteners with different lengths. One ASTL for 130 to 170-millimetre slope insulation and one for 170 to 250 millimetre for example. The longer the combinations, the more slope you can bridge.
This way you always work more efficiently, easier and with less chance of errors in the roof covering when working with height differences in concrete floor slabs. For all your efficient securing.


2. Renovation projects

The ASTL comes in better than the standard combinations. With renovation projects, you often have to deal with significant differences in the existing building thickness. For example; you have an old concrete roof with or without insulation, old bitumen roof layer is on top of that, even overlayed 1 to 2 times, what brings you on 3 to 4 layers of bitumen on top of each other which gives a lot of height difference, to more than 1 cm.

When using a standard combination slope-fastener, you may just miss 1 or 2 centimetres in length of the screw in the overlap.

If you have the ASTL slope-mounting combination that's needed, you're secured, in this case you also need fewer combinations - 1 or 2 combinations will do - you are always at the right depth in the various concrete layers, without the risk of damage.


3. For PREFAB elements

The risk with prefab concrete roofs is the same as with the scenarios as mentioned above. There is always a difference in thickness or height because you fasten such concrete slabs next to each other in one go. In severe cases, there may also be up to 5 centimetres in height between them. As a result of that, the isolation on top also will be misaligned.

These are not the vast differences as with a slope, but it remains a risk on your roof. In our opinion, when it comes to roofing, you have to eliminate all hazards.To prevent this, you better work with the ASTL combination than with a standard combination that cannot bridge these differences (literally and figuratively).

Guardian fastening system


Extra benefits:

Not only does the ASTL fastener can be of good service in the roofing scenarios above as the solution for height differences. It has a few useful plus points:

  • This fastener is 100% step-safe.
    The telescopic effect of the tulle always moves with the insulation. If you walk next to it or step on it, the tube moves downwards together with the roof covering, because the screw can move freely in the tube.
  • The ASTL has the same calculation values as a standard combination; 600 to 800 Newton design load - sometimes even more - depending on the type of grommet and roofing membrane.
  • It is extra safe to attach in combination with a drill plug. You always have the right depth with pre-drilling in concrete. The drill plug still provides a slightly wider diameter in the insulation and ensures that the grit is smashed under the insulation! There will be no grit on top of the borehole or fall back into the borehole, causing you to contaminate the roof and then do not grab the fixing screw properly. Security and safety first!
“The invenstment is worth it”

“This product is only a small part of the total purchase price of a roof. If you like saving money - by working with the non-certified or standard combi - you run many risks. Your expensive roofing material can blow away or get wet, apart from inventory in the building itself, which is also exposed to damage. The most expensive components of your building are destroyed because you have saved a small percentage in total on the 2 to 3 per cent costs of roof-mounting material. The ASTL is, therefore, a small part of the purchase price, but extremely important as an investment in damage and risk reduction.”