Author Archives: Sam Armijos

Fabric Structures: Q&A

The FabricArchitect continues to go thru the alphabet of Fabric Structures and today looks at the the letter “Q”.

I thought finding words starting with the letter Q was going to be hard but the words came pretty quick:

Queensland (Australia)

Queensland (Australia)

If you want to see alot of fabric structures, head over to Australia, particularly Queensland which is the northeastern part of that beautiful country. I was in Brisbaine in 2000 visting SSP (Shade Structures Pacific) and just loved to see that fabric is well received as a building material and that there were many uses for it. Hotel entries, outdoor dining, walkways, interiors, etc. I dont know if there is a law or requirement in that country but I found them everywhere. I applaud the design community for getting them built in so many places. Architects love to quote “Learning from Las Vegas”. People interested in Fabric Structures should “Learn from Australia”.


Small scale fabric structures include umbrellas, barrel vaults and canopies built to code and built to last. One common design in the marketplace is a single post “hypar”.

Birdair calls theirs “Quasar”. FabriTec calls theirs the “Aurora” but it is the closest thing to custom at a standard cost. The structure has a nautical feel to it with stainless steel exposed cables and a canopy cover that is quite eye catching. These structures come as small as 12′ and I’ve seen them as big as 30′. If you want to do something beyond your standard umbrella, this is the way to go.


Most people don’t even know where Qatar is but if you follow soccer, you know Qatar is adjacent to Saudi Arabia, Bahrain and the Persian Gulf and will be the host of the 2022 FIFA World Cup. Alot of new stadiums are being planned there and as you can imagine, they all need shade which means look to see a variety of new fabric structures in the Middle East.

“R” comes next.

Fabric Structure P’s

Today, the FabricArchitect looks at the letter “P”

  • point supported structure
  • patterns
  • PVC

Point Supported Structures

Point-supported structures are forms with a minimum of four points of attachment with either straight or curved edges that produce a clear span with no center mast.  The classic point-supported structure is the saddle shape or hypar.

Point-supported structures can have a variety of shapes depending on the number of anchor points and the position of the supporting elements, however, double curvature is essential.


Computer patterning is the process of developing a two dimensional representation of a three- dimensional membrane surface. The patterns are created with compensation factors. Compensation factors are the reduction made to a cutting pattern to allow for the expansion of the membrane once in tension. In some cases, decompensation (addition made to the length of a piece of the membrane which was shortened by compensation) is required in order to meet certain geometric conditions such as fixed points where there is no access for tensioning. The panels are sized according to the width of the fabric being used.


PVC (polyvinylchloride) or vinyl coated polyester is the most common and cost effective membrane material for both temporary and permanent tension structures. The material is soft, pliable and less expensive than PTFE. It is available in a variety of types to meet a wide range of structural requirements. It has a minimum of stretch and shrinkage in a wide range of temperature and humidity conditions and the coating process prevents mildew, stain and streaking.

Most PVC fabrics will have some form of top coating applied to keep them looking new and clean. These topcoats can be acrylic solutions, polyurethane-acrylic solutions, PVDF solution coats or a PVF film lamination. Vinyl laminated polyester is primarily used for temporary structures while vinyl coated polyester is used for both temporary and permanent structures.

PVC material has a life span of 15-25 years and comes in a variety of colors and textures. This material is sealed using radio frequency (RF) equipment.

Ouch, “Q” comes next.

O My Fabric Structures

Happy New Year!

The FabricArchitect begins the year with the letter “O”.

OMG that’s me in front of Bucky Fuller’s Geodesic Dome in Montreal. Great structure. Good Times.

I thought I would use this letter to show some great images.

Don’t use this word much but most Designers and Architects refer to an oculus as a large opening to the sky, like a skylight. The Pantheon always comes to mind.

In the world of Fabric Structures, it is more like a “bale ring” which is a compression ring around a mast used to lift and tension a membrane. Circus tents are often found with them. The opening can also be installed anywhere on the membrane as long as there is a cable loop or some kind of component keeping the membrane from tearing.

Orange, red, green, blue. It doesn’t matter what color but “what color is available?” is a common question asked in fabric structure discussions. If you are looking for shade only and working with small scales, making structures using colorful fabrics is a great solution and there are plenty of colors and options available.

As projects get bigger and size and span get longer, fewer colors are available. Especially for waterproof membranes (PVC, PTFE, Silicon, etc.), color is available in minimum runs only.

A bigger issue  is that one’s pigment (skin color) will show the color of the membrane which may or may not be flattering (i.e. you look green under a green tent, yellow under a yellow tent, and yes, orange under an orange tent). I often recommend the use of white fabric and tell my clients to invest in lighting to change the membrane to any color.

Orlando is one of my favorite places to go because you can get a look at some nice fabric structures there in all shapes and sizes.

If you arrive by plane, the airport has some nice structures which cover the arrival and departure areas. Circ de Soleil has their signature structure there and there are plenty of interesting membrane structures at retail shops and at the Disney theme parks and hotels.
Next is “P”.

Fabric Structures “n” Membranes

Fabric Structures consist of three major things: Structural system (steel, wood, concrete, etc.), edge component (cable, belt, rope, etc.) and fabric (too many to choose from).

To the right is FTL’s U.N. Annex Entry Canopy in NYC.

Today the FabricArchitect talks about “N” and there are a couple of N words that come to mind and they all have to do with fabric.

  • Naizil
  • Nanogel
  • NovaShield


Headquartered in Italy with offices in Canada, Naizil has been manufacturing PVC coated fabrics for truck tarpaulins, awnings, tension structures, digital printing and many other applications for over 50 years.

They have a couple of interesting products in the market for Fabric Structures.

Their Cover series of coated fabrics have been designed to meet the high quality standards required for tensile structures and large coverings. All “Cover” products are self-extinguishing and protected by  a PVDF sealable topcoat. They also offer an extra treatments such as ROTOFLUO P which is a non-sealable PVDF coating which makes it longer lasting.

They have another product called TITAN W  which has Titaniuim Oxide (TiO2)which represents the cutting-edge in the protection of PVC coated fabrics.

Compared with conventional topcoat systems present in the market, these new protective coatings are being introduced that further increase the life of the product, keeping it cleaner.

Naizil also offers photovoltaic thin film on some of their membranes under their SolarPanel brand. The Nazil SolarPanel comes rough 5′ x 7′ and has an output of 75Wp per panel. The panels produce direct current that afterwards can be transformed through an inverter to alternate current and then can be used in standard electrical systems.

Other PVC manufacturers to check out are Seaman, SergeFerrari and Mehler.


Imagine Fabric Structures that are light and have insulation.

Thats’ where Nanogel or Aerogel comes in.

You’ve heard these brand names before being used on a bunch of things like glass and metal. Well, you can get it on fabric, too.

For example, Translucent skylights and membranes are now incorporating Lumira™ aerogel (formerly Nanogel® aerogel). Not sure why they changed names. Although it provides a little less translucency than traditional translucent materials like teflon coated fiberglass, acrylics or polycarbonate, they are an excellent value and can substantially reduce energy costs and provide a great return on investment.

“Nanogel-type” membranes can increase the R-Value of a membrane to be significantly higher than a normal skylight or membrane.

You get natural light and a high level of insulation all in one product. Pretty cool or warm.

See companies like Cabot, Birdair and Aerolite.

NovaShield II

NovaShield II is a polyethelene used for clear spans, agricultural and industrial structures.

The brand name comes from Intertape Polymer Group and Engineered Coated Products.

Designed to meet the industry’s highest standards, NovaShield II polyethylene fabric has great strength-to-weight ratios and its lighter weight makes for easier, faster installations. NovaShield  is an alternative to PVC. NovaShield II is ideal for use in membrane structures or any other fabric application requiring fire retardant and UV characteristics.

Check out fabric from Interwrap too.


Next comes “O”.

Fabric Structure “M”‘s: Mast, Moss and Membranes

Sorry for the delay.

I got caught in September’s Hurricaine Irene and lost my basement and office which included my priceless (to me) fabric structure book collection some personal items but as they say, “less is more”. I have less in my house now but I appreciate more what survived the flood.

October brought me an early winter snow storm which left my house with no power for  a week. Lets see…no power…no sump pump working…no refrigerator on…no furnace working. You get the idea.

In November, I managed to get of of town in time to do some business only to find out that I was walking with a  ruptured achilles tendon and I didn’t know it!

I’m on crutches now for months followed by months of rehab.

But I still can talk about fabric structures!

Lessons Learned?

My body is like a fabric structure, it is made of a few components and all components rely on each other as awhole. If one piece is “sick”, in this case my achilles, I need to modify my design or posture, adjust my process or way of completing a task and try to be as light as possible to prevent putting extra weight on my foot or the earth!

In other words, I got to watch my diet!
Today, FabricArchitect talks about the letter “M”.

With “M”, I think of

  • Mast
  • Moss
  • Membrane

In some ways three things you aboslutely need when it comes to designing and building fabric structures.


The mast is the ionic, doric and corinthian column of the tensile world. It is both structure and architecture. It is the spine. It is conduit, support systems and wayfinder. The mast can do so many things so take advantage of it. It can support electrical, sound and be topped with a bale ring left open to the sky or enclosed in glass, metal or a variety of other materials. The perimeter mast can be pin connected or moment connected and be a leader for water or an edge for a sidewall.


I met the Artist Bill Moss when I was in College and the name has lived on to be the name associated with the trade show industry and the interior fabric stuctures. My friend Debra Roth of Pink Inc. now does her thing thru the Moss label and there are many companies out there doing “Moss type” structures (some better, alot worse). Watch out for wannabees. Most of the structures use a stretch fabric and now with improvements in printing  on them, there are unbelievable results. Experiencing Interior fabric sttructures is a great way to get into the business whether as designer, user, client or fan.


The membrane is the skin.  Make note that most, if not all, interior membranes cannot be used outside. Some of the things you can do inside cannot be replicated with an outside structure. Membranes come in all colors and strengths and translucency. For decades now, the industry has been accustom to teflon in the 10-12% range in translucencey, PVC in the 6-15% and Tenara in the 20-40% translucency. Along comes ETFE with transparency ranges from 50-97%. That’s progress.

But what’s next?

I am always looking for the next “skin”.

Fabric with PV cells already embedded in the material? A material that chances color to its mood. More insulated than traditional insulation. Able to “cover” tall building  in a single bound.

Buildings are getting lighter and lighter. Less is more, Light is more, Fabric is even better.

Think out of the box, design out of the box, detail out of the box and you will find yourself building a fabric structure.

See you at “N”.

Fabric Structures and “L”: Losberger, Light and Lessons

This week we look a the the letter “L”.

It’s August here in the US and its hazy, hot and humid!

When its hot, people look for shade. Even my little big guy Elwood, nickname “L”,  is smart enough to know where to find good shade.

When I think of the letter “L”, the following comes to mind:

  • Losberger
  • Light
  • Lessons


Losberger is a European manufacturer of tents made with aluminum box beams found around the world. Real nice and clean. If you are looking for temporary structures with permanent looks, check them out. Other companies making simliar structures include Fabritec, DeBoer, Roder, and Neptunus.


Fabric Structure are commonly considered when there is a need for a “lightweight” structure that uses a “light” material that allows daylight and is reflective enough to create spectacular lighting experiences.

Less is more, Light is more, Fabric is even better.

I often get asked what color fabrics are available for fabric structures or why are all fabric structure white.

The answer is simple.

When you are under a fabric structure where the membrane is a color, because of the material’s translucency, your skin will tend to have the pigment of that color. For example, if you are under a yellow tent, you will tend to be “yellow”, green, “green”. You get the idea. You don’t want to have your picture taken under a pink or blue tent. My advice is to stay with white (it doesnt go out of style) and invest in the lighting.


When its hazy, one needs protection from the element. When its hot, protecting one from direct UV and heat gain is essential. When its humid, natural ventilation would be great to have.

Designed properly and with the right material, a fabric structures works well to combat the hazy, hot and humid days of summer. Its does pretty well in the Fall, Winter and Spring too.

In twenty years of doing this, There are still lessons to be learned.

I break it down to Design, Detail and Delivery.

Design takes time. One can design the same form in two different places and you will get different results. The shade will be different. Natural ventilation will be different. How it is seen from a distance will be different. Take time to review the design.

Details takes will. Details can make or break a design. Details can also make or break a project financially. Some details are cheap. Some are expensive. Many times, you get what you pay for it.  Details come in all shapes and sizes. Some seen, not seen but all play a role in the overall design.

Delivery is more than just a package. Just because the structures has arrived on site that doesn’t mean the job is done. 99% of a fabric structures is not built on site. It’s built in a controlled environment and should be shipped with great care. The final 1% is the installation and seeing the structure installed properly, the membrane tight as a drum and the structure performing is the goal. That means doing what it says it was going to do. Shade, shelter and more.

See you in September to talk “M”.

Fabric Structure’s Special “K”

The FabricArchitect looks today at the letter “K”.

K could easily be Kevlar or kips per foot, but I always think of my daughter Kay C. Armijos (#13) first who was born in Kansas City when I was doing fabric structures in the MidWest in 2000. Another story for another day.

Todays words are:

KD Kanopy

Keder is a hard rubber rope that is usually found at the edge of the membrane where it is going to be clamped or in an extrusion for tents, tarps, signage and tension fabric structures. It comes in a number of diameters and it is important to have at the edge of the material in order to keep the membrane from slipping out of its component. Kedar is rarely mentioned in a design meeting but it will appear in the details and on site. Check out American Keder.


Lately, there is a desire for designers and clients to want their fabric structures to “move”. They want to be able to open and close it at the push of a button or be adaptable for a variety of environmental conditions. BC Place in Vancouver will have a retractable portion to its roof and many new stadiums are bringing “Kinetic Architecture” to the design. Uni-Systems out of Minneapolis,  Hardesty and Hanover  our of New York and Clauss Markisen out of Europe are just a few of the new names in the fabric structure business who are introducing mechanized devices to move lightweight structure.

Also, check out folks like inventor Chuck Hoberman and Engineer Craig Schwitter of Buro Happold who are collaborating under the Adaptable Building Initiative to explore new and exicting retractable structures.

What could be more adaptable than a membrane structures?

From the nomads to the next dome stadiums, Kinetic Architecture is here to stay.

KD Kanopy
When I was getting into this field in the mid to late 80’s there was a number of “pop up” fabric structures coming to market. Camping tents and inflatables were coming of age and there was a peculiar new item being sold. Fleamarkets and outdoor food markets were growing in popularity and owners were making temporary structures with conduit tubing, plumbing fixtures and speedrail systems.

At the same time, “scissor bar” framing systems that were attached to fabric where being introduced. One that caught my eye was KD Kanopy where aerospace technology meets flea market tent. There are plenty of companies in this market now.

Funny how these structures are now part of our popular culture.

They are seen at tailgate parties, picnics, soccer games, races and special events. I use to call them big umbrellas with four legs.

These are not your grandfather’s pop up tents anymore.

Try one and buy one on for size.

Next week, We shall talk about “L”.

The ABC’s of Fabric Structures returns: The Letter J

by Sam Armijos

Two kids, a dog, 7 days a week of sports and preaching and promoting fabric structures all over the place can keep you pretty busy and away from writing but I’m back. I was stuck on the letter “J” because all I could think about was the name of my first born (“Jay #13”) and he was born when I was working on the Uni-Dome in Waterloo, Iowa in 1998.

When it comes to fabric structures and the letter “J”, the following comes to mind:

  • Jacking
  • Jacksonville
  • Jakob


“Jacking” is a term used for raising the mast or columns of a structure using hydraulic jacks. I recall a “sandpit” detail used at both Jacksonville, FL and at Fabritec’s Nautica Amphitheater  (now the Jacobs Pavilion) in Cleveland to raise the mast to tension the membrane from the ground instead of up in the air.

You basically raise the mast that is sitting in a large sand pit and add sand or shims to it to keep it level. Pretty simple and it works too! Gotta find that detail. Maybe you have seen it?

Jacksonville (Amphitheater)

Jacksonville Amphitheater also known as Metropolitan Park is one of the first permanent fabric structures built in the US for musical performances. Designed by my friends at FTL who I once worked for, the structure was the first of its kind on the waterfront and was followed by the likes of Pier Six Music Pavilion in Baltimore, Bank of America Pavilion in Boston and Ntelos in Portsmouth, VA, just to name a few. That structure is at least 25 years old and could probably use a recover by now but it still rocks.


Stainless steel cables and hardware always come to mind when discussing fabric structures and I always seem to see Jakob, a swiss maker of cables and fittings at trade shows. The do handrails, green screens, wire meshes, you name it. Nice stuff. You can find these types of cables and hardware from the likes of Ronstan and Pfeifer too.

Next week, we talk “K”.

Inverted, Interiors and Installations: That’s my Fabric Structure

How many times have you heard the expression, “there is no “I” in TEAM”.  How true when in comes to fabric structures.  FabricArchitect is talking Letter “I” today:

  • Inverted (umbrellas)
  • Interior Applications
  • Installations

Inverted Umbrellas

I will never forget the first time I saw an inverted umbrella. I was at RPI writing my thesis on fabric structures in the mid 80’s when I saw these cool “upside” umbrellas Frei Otto had designed for a concert tour in one of his IL books. These structures folded like an umbrella but when you opened them, wow…A Tulip shaped membrane that created a unique shape and had the ability to collect water…how sustainable in the 1970’s!

I next saw them at an American Institute of Architects (AIA) show where a scaled but workable model of a retractable inverted umbrella designed by one of Otto’s disciples, Bodo Rasch, was being displayed by the folks at Gore, makers of the Tenara PTFE (now sold by Sefar).

The idea is simple. Take the most common form of the umbrella, and turn it upside down. You can design them as a multitude of singular structures or have the membrane be made in one piece. You can have them made permanent or collapsible. The idea of collecting water from a fabric structure is becoming more common and by collecting all the water into a cistern or catch basin, there are a number of things you can do with the water.

Interior Applications

I had the pleasure of meeting Artist Bill Moss , the creator of the “pop up” tent during my studies and got to see first hand the “new” fabric structures being created for tents and tradeshows which are now common throught the entire industry. I also met folks like Cyndi Thompson from Transformit and Debra Roth of Pink Inc. along the way who are taking this kind of work to the next level. Building interior fabric structures seems very easy but they are not. Unlike Tensioned Membrane Structures, theses are sometimes created as full scale mockups and require an understanding of existing interior and exterior building conditions for proper design, planning and installation.

If you want to look at materials for interior application, look no further than the industrial fabric industry and Theatrical Drapery. There are lightweight PTFE materials used for ceilings in dome stadiums, PVC fabrics are used for interior tensioned fabric sculptures while theatrical drapery materials from companies like Rosebrand and Dazian are used for a softer look. Spandex/Lycra is another common material used for transforming temporary and permanent spaces but require the material be fire treated prior to fabrication. Interior fabric structures too come in single or multiple units or can be made into one large membrane.


It is so easy to overlook the installation when it comes to fabric structures. They look so nice on paper and the final completion can be a priceless experience, but you would never get there if you didn’t know or understand how the structure is erected or tensioned or made safe to walk under. The most important thing for you to know is to understand the erection procedure or “means and method”. Make sure you ask you designer, engineer, fabricator and installation team to go over how they intend to put up your fabric structure. You do not want surprises.

Check this video out of how to build a new fabric structure roof at .

For more info on Stadium roofs, visit, Fabritec.

Next comes “J”

Fabric Structures and Horst, Hypars and Hospitals

This week The FabricArchitect looks at the letter “H”. The first things that come to mind are:

  • Horst (Berger)
  • Hypars
  • Hospitals

I first started studying fabric structures at Rensselaer in 1985. One of my thesis advisors was an Engineering professor named Bill Spillers. Bill recently passed away in 2010. When I asked him to help me with my thesis on Fabric Structures in Housing, he told me the person you need to meet first is Host Berger.


You cant’ talk about fabric structures without talking about one of the great pioneers in the industry: Horst Berger. Besides “Frei”, he is one of the few personalities in the industry who is recognized by a single name.

Born and educated in Germany,  Horst joined Severud Associates in New York City and worked on projects such as the St. Louis Arch, Madison Square Garden, and Toronto City Hall. In 1968, he formed Geiger Berger Associates with David Geiger and gained international fame for creating a specialized firm devoted to air and tension structures for permanent applications. There are a number of engineers around the world who gained experience in tension structures from their time spent at Geiger  Berger.

Berger  is credited for designing and engineering a number of structures and was instrumental in both the 105-acre roof for the Haj Terminal  and the Denver Airport which recently was awarded the 25 year award from the AIA.

He’s still around and loves talking fabric structures.

His book, Light Structures: Structures of Light inspired me to write my own book, Fabric Architecture


I can give you all the mathematical jargon on what a Hyperbolic paraboloid is but it wont help you get your fabric structure get built. What you need to know is that this is the starting point to any fabric structure. All fabric structures need to have some form of a hypar or saddle shape to be stable. Hypars must have at least four points (two high and two low and opposite each other). Designers as well as fabricators love hypars. You can create endless concepts but you have to follow the rules.


Hospitals need Fabric Structures. From covered parking to covered walkways to entry canopies to interior applications, a hospital has a number of places for fabric structures.  Besides UV protections, fabric structures are ideal for shading outdoor spaces for the elderly as well as playgrounds for the children. It can be used in outdoor seating areas for employees and screen mechanical equipment.

Next we go to “I”