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Drop Everything : the basics of high-performance drop seals from athmer

It's likely you're not dropping "automatic door bottom" into everyday conversation (yet), but there's still a lot to be said about these unsung heroes of high-performance door openings. If you're looking for sound isolation and exceptional energy savings, this is how you do it.

A market leader in the manufacture of drop seals for over 60 years, athmer's extensive range of solutions have proven themselves millions of times over in buildings all over the world. Let's have a look at the basics of drop seal function and technology and review some of the many solutions that athmer offers for doors of all types and functions.  

The Basics of Drop Seal Technology


The simplest job of a drop seal is to close the gap between the bottom of the door and the floor—and also between the top of the door and the ceiling or header— as part of a total solution that seals all sides of the door from smoke, light, noise and dirt, and controls the loss of energy through the opening. Doing this simple job at the level of precision and durability required by high-performance building projects means specifying athmer drop seals.


Dragging grit over beautiful flooring may drive some to replace traditional gaskets and sweeps with automatic door bottoms, but drop seals offer many other performance perks over the simple flipper seal including keeping out the weather, noise and smoke. 

Some of its basic features even help ensure that the installation goes off without a hitch. For example, the removable actuator that can be adjusted without tools. Its design eliminates the need for a protective pressure strike plate on the jamb, a big aesthetic plus. Additionally, on a gritty, debris-strewn construction site, you can simply remove the click-in actuator until all is clean and ready for hand-off. This way you won’t suffer the embarrassment and cost of replacing silicone seals damaged by the usual job site chaos.


You are also able to easily remove the inner profile with the door installed for quick maintenance. 

An Overview of athmer Solutions


Here are a few common features shared by most athmer drop seals :

parallel activation : other drop seals come down on one side first then the other. the series of spring mechanisms in drop seals from athmer allow the entire width to deploy straight down which keeps the seal from dragging dirt and grit, avoiding damage to the floor and the seal.

no lateral travel : other drop seals will shift horizontally when deployed, leaving at least one end of the opening incompletely sealed. athmer deploys without this movement, ensuring the gaps are completely sealed.  

self-leveling : when floors are uneven, the mechanisms within the athmer drop seals compensate while maintaining equal pressure along the entire width of the door.  

self-extinguishing silicone gasket : athmer's robust and pliable silicone gasket material is sourced within 200km of Athmer's facility. It delivers dimensional tolerance and a lifetime of performance.

non-marring actuator : no need for jamb strike/press plate, most models feature a removable actuator made from a high-density polymer for easy adjustment. This also allows the builder to remove the actuators during the construction phase when other seals tend to see damage requiring gasket replacement.

engineered and tested for top-performance : UL-Listed, tested beyond one million cycles, and independently tested for sound isolation up to 52db. Some models like the Rainstop® provide exceptional Class 7/600 Pascal protection from wind and driving rain.


Schall-Ex® L-15/30 WS : The Any-Door Solution

Like all of the Schall-Ex® models, the standard Schall-Ex® L-15/30 WS delivers : 

  • Up to 52db sound reduction!
  • Parallel deployment along the entire width of the door. No dragging grit. 
  • High quality silicone gasket that is trimmable on site (oh, and self-extinguishing)
  • Easily adjustable without any tools.
  • Removable actuator for disengagement to survive the dirty chaos of a construction site.
  • Maximum Deployment : 3/4"
  • UL-Listed

This basic Schall-Ex® model is so far ahead of the run-of-the-mill drop seals you may be used to that we want to give everyone a chance to try them. A limited number of free samples are available. Contact us for details : +1-800-362-1484


IMPORTANT INSTALLATION TIP : One of the best things about the athmer drop seals is that they're easy to adjust, with no tools required. Just remove the actuator and adjust the travel of the seal so that it just touches the floor or threshold. For best performance, you should be able to pass a sheet of paper underneath the door (left diagram above). Smooshing the silicone down hard (right diagram above) does not provide a better seal and over time will deteriorate performance over time.


Schall-Ex® L-15/30 Pivot : The Heavy-Duty Pivot Solution

With FritsJurgens pivot Systems advancing the art of the massive pivot door, sealing exterior pivot doors has become a manifest challenge. athmer's heavy-duty Schall-Ex® solution has established itself as the state of the art. The standard press-in actuator has become an adjustable roller that smoothly navigates the door's approach to the jamb. All of the hallmarks of the Schall-Ex® line are here and ready.


In order to work with the FritsJurgens System M+, the drop seal needs to be mortised alongside the pivot closer body for the entire width of the door. Obviously, thicker doors are required to accommodate both. This doesn't generally pose a problem as many of these large doors are being engineered on the beefy side. If you are interested in this solution, please give us a call. Getting these doors to the next level of performance using the proper drop seal is what really gets us excited! 


Schall-Ex® 14/35 EK : The Clean-Cut Solution

Until now, drop seals in our market have mainly been something that the commercial hardware dealer specs and provides for their projects. The usual commodity brands tend to arrive on site and the expectation for refinement is low.

For some designers and their clients, the idea of all that "unsightly" gasket sticking out of the edge of their premium residential door can make it hard to sell the benefits of using a drop seal. 

Fortunately, athmer has something to soothe the eye of the aesthete while still delivering great performance.
A clean face for fantastic functionality


The EK version of the Schall-Ex® was developed for the UK market where propriety is perhaps as turned up as it is here. The nice clean faceplate keeps things tidy on the edge while still delivering, if not the full sound/air/light blockage, a high and healthy dose of all those. What you lose is whatever was being blocked at the jambs by the extending silicone.

We've seen this model become a great option for high-end residential interiors.


Schall-Ex® L-15 FS : The Retrofit Solution

The pandemic made acoustic isolation a real concern for anyone holding meetings in their bedroom-slash-office. 

While the other Schall-Ex® models require you to prep the door for the seal prior to hanging it, the FS series allows you to get the benefits of a great drop seal on any door even after it's hung.

For some, this is not the ideal look, but with the Schall-Ex® FS model, for retrofit situations, athmer provides a clean solution with concealed fasteners, and some optional finishes to help it blend in. And the installation is a do-it-yourselfer's walk in the park. 


Rainstop® : The Barrier-Free Weatherproof Solution

Requirements for barrier-free design, construction and living are becoming increasingly important, and how entry doors manage that threshold between inside and out is where athmer's Rainstop® steps up. Its brawny profile features a multi-chamber silicone seal that keeps storm winds and driving rain from penetrating. 


Schall-Ex® Ultra : The Coastal-Ready Edition

The Ultra has been engineered for use in exterior doors of all materials. The usual athmer mechanisms include stainless steel springs housed in an anodized aluminum profile. Having passed a 480-hour salt spray test, this is the one you want to use in coastal or other corrosive environments.


Stadi LD : The Delayed-Deployment Solution

Shutting a door shouldn’t mean fighting with the ventilation system.

The versatile Stadi line from athmer includes models with the delayed deployment feature, a technology that delays actuation of the seal by a few seconds to allow air to flow under the door prior to making the seal.

This delay prevents pressure differences from affecting the door operation. This feature is particularly useful in positive-pressure environments, a growing requirement in hospitals, biomedical labs, and even office environments. 

The Stadi line was developed specifically for the OEM market and includes profiles in various sizes to be integrated into proprietary profile grooves.

Stadi models come in non-delayed-deployment models as well.  


Schall-Ex® VHH : The All-Around Sliding Door Solution

Sliding doors present one of the trickiest situations for sealing a door. The thing leaks from all sides and, with sliding track hardware, you have the challenge of the entire top of the door being inaccessible to a standard seal. 

athmer VHH is a four-sided system that allows you to button up all edges, including a standard sliding door drop seal at the bottom and patented profile integrated into the top of the door that accepts most sliding door track hardware carriages to allow a seal to engage with the wall. 


Schall-Ex® Glass Solutions : New Suite of Solutions

Drop seals can be useful in office and other noisy commercial environments as a way to achieve the necessary privacy everyone needs to be productive. athmer offers clean-lined solutions for frameless glass doors from 5/16" to 3/4". The new glass door drop seal family features a special high-tech adhesive tape. Instead of the usual silicone adhesive or complex UV bonding, installation using the special adhesive tape from athmer enables quick and efficient bonding without drying times.

The new line also features a black silicone gasket profile and black actuator to bring the aesthetics of these high-performance drop seals in line with many of the demountable partition systems in which they find themselves.



Made in Arnsberg : athmer's commitment to sustainability

One of the reasons for the ubiquity of drop seals in Europe is the universal requirement for buildings to be energy efficient, to avoid wasting energy in heating or cooling spaces. athmer's mission is to provide the highest quality drop seals for this effort.

But they don't stop there. athmer sources all of their materials, and manufactures their products entirely in Germany in award-winning net-zero emission facilities run on hydro-power, with the grounds maintained by local grazers. All of athmer's products are covered by an Environmental Product Declaration (EPD) in accordance with stringent European standards, EN ISO 14025 and EN 15804. The EPD is further evidence of athmer's wider commitment to sustainability and permits their product to be used in certified Green Buildings throughout the world. 




No Seal, No Door : making doors that perform 

athmer believes that when you close a door, one side should be completely separated from the other from light, noise, air, weather, and even radiation. The role of a drop seal in delivering the isolation that idea requires inspires them to innovate and improve their product line.

Learn more about athmer and their wide range of drop seal solutions :


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