Warp-free, lightweight, insulated honeycomb panels


See: Why Architects Spec Sing Core

What we do —

We supply the biggest and best door companies in the world and serve the top architectural firms. Our patent and patent-pending technology allows us to solve the issues often faced with large doors.

  • Exclusive 50-year warp-free warranty
  • 50 years structure guarantee.
  • Custom door panels built to your specifications
  • Build according to your weight specification.
  • Stronger than steel
  • Any size
  • Any skin material
  • Lightweight
  • Ultra straight
  • Precision Dimensions
  • Eco-friendly warranty

No other Eco-friendly door base material is so lightweight, strong, or high precision. That is why the biggest and best designers, millworks, door manufacturers, and contractors seek Sing Core as the solution to their various challenged jobs. If you have any doubt about Sing Core’s high performance and superior warranty, contact your favorite high end millwork or contractor.

SingCore in AIA Center for Architectural Design, Seattle

How Sing Core Works With Architects

SingCore gives architects the flexibility to realize their creative designs without worrying about the details of construction. Our doors panels come in any look and any size – you just specify the dimensions, material, and “Sing Core inside!”

Don’t Let this happen to you.

Occasionally, an end user will contact us about their door with Sing Core inside warping. After checking the details, yes, Sing Core was specified, and the contractor did submit a price quote request for the door in question, but no such door was ever ordered, built, or shipped from Sing Core.

In other words, trust your contractor but verify.   See: Sing Core Substitution Trick

We will not tarnish your reputation. We are here to make your project as amazing as possible, and deliver 50-years warp-free and structure guarantee to enhance your image even more.

One thing’s for sure: No other Eco-friendly door could be made in the world that is so lightweight, fully insulated, stronger than steel, and guaranteed to remain warp-free for 50 years. Only doors with Sing Core inside can be so high precision (+/- .006″ tolerance) and built to outlast their 50-year guarantees for full structure and non-warp.

The process works something, like this:

  1. The Architect specifies, “SingCore” inside the products, let’s say, a large pivot door
  2. The General Contractor seeks out a qualified Millwork who obtains unfinished pivot door from Sing Core
  3. Sing Core manufactures the pivot door blank to architectural specs and ships to millwork
  4. Millwork finishes and installs hardware and provides finished pivot door to the job site
  5. Installers hang and or install the door

Achieve More

The unique attributes of patented SingCore assists in bringing the creative concepts of architects to life in the real world. Ideally, architects who understand SingCore’s unique characteristics specify SingCore in their designs.

We are seeing even more architects working in tandem with our team to solve the challenges with traditional materials. Basically, when a problem associated with weight or strength rears its ugly head, SingCore is the Eco-friendly solution. In the event the architect was unaware of the size and/or weight issues associated with his or her design, it is not uncommon for the general contractor or millwork to seek SingCore to solve the problem.

Check out how to select Horizontal Grain Doors for sensitive applications


By using out online submission form, you can see an instant 3D rendering of your door, and access a free door drawing instantly.



For Door Specifications Click Here

To contact SingCore staff, architects should fill out our online form with the specifications of their project to obtain a response and initial price quote.

Click Here to Get an Estimate

SingCore Solutions

We see trends in the problems associated with particular architectural designs where patented SingCore is clearly the solution. Though we ship all over the world, most of our products ship 3,000 miles away to New York (less expensively than other materials due to the decreased weight) where we solve issues for FAIA members’ concerns about large sliding doors and help door companies deliver warp-free large doors to increase integrity and viability. We also assist AIA chapters (like this one in Seattle) create outstanding Centers for Architecture and Design. (Follow links for more information on these projects.) See Clients List

Here are the most common problems solved

Overweight Doors

Any doors built with SingCore inside will weigh a fraction of other materials, yet can host any flat exterior material per architectural specification. For instance, a solid hot rolled steel door would be extremely heavy, which is a concern in terms of expensive hardware and potential additional stress and strain on the structure. The same hot rolled steel door with SingCore inside (approximately 4-6 lbs. per cubic foot) weighs a fraction of the weight without compromising strength, as SingCore is stronger than steel (660 PSI) pound for pound. See Steel Doors

Oversize Large Doors

Big doors are problematic due to their size which causes concerns of weight and potential to compromise due to warping. SingCore is used extensively in large doors to maintain their structural integrity, to be straight and stay straight over time, so as not to create problems with leaky door seals requiring regular maintenance. Only doors with patented SingCore inside can be structurally guaranteed to be true flat and warp-free for a full 50 years, even if the large door in question is made of natural wood(s). See Large Oversized Doors



Sing Core is made in the USA with the most sustainable processes and composite materials, such as natural wood fiber inside the core, formaldehyde-free glue and the manufacturing process uses manual labor and very little energy to produces with little or no waste. Plus, due to the lighter weight of Sing Core (about 10% the weight of solid wood products) we ship Sing products all over the United States and the world abroad, at a fraction of the cost while reducing the energy consumed and the associated carbon footprint in the transportation process. In addition, Sing products are reusable and repurposable following installation or demolition.


The issue of heavy weight is the first thought that comes to mind as Sing’s core is so effective at reducing the weight of the otherwise overweight modern steel pivot doors, which results in a door that can be shipped less expensively, easier to handle in the shop and on the job site, and requires much less expensive “heavy duty” hardware to accommodate these modern steel exterior doors with Sing Core inside. Whatever the steel weighs (+ 10%) will be the weight of the door. The heaviest gauge you would need is 18G, and 20G is best and looks like a solid steel blank.

Stronger than Steel

Sing’s revolutionary technologies empower contemporary architects, door designers, the biggest and best companies to provide their clientele with modern stainless steel entry doors that are lightweight yet stronger than steel pound for pound. Sing Core was tested to far exceed 660 PSI.

How can 20 Gauged steel be so much stronger? Why? See unbreakable glass:

Glass stronger than steel? Even hitting unbreakable mirror with a hammer does not break.








High Precision

When compared to other core materials Sing Core is extremely high precision maintaining the highest tolerances (+/- .006 in.) across the entire span of the panel. You can feel confident knowing this lightweight, high strength building material maintains a high level of accuracy throughout your project.

For years, Sing Core has been providing high-end local and nationwide hot press veneer professionals with premium core material that eliminates the need for crossbanding.

Architects are increasingly specifying their large high-end hot pressed veneer panelized walls, features, and doors have Sing Core inside (accounting for about one-third of all our products which are sent to the greater New York-area). The contractors generally contact Sing Core directly first, due to being specified. Though Sing Core does not actually do the veneering. Sing Core provides the high precision substrate that is shipped 3,000 miles from the manufacturing location in Washington State, to the high end millwork in New York (or wherever the nearest hot press specialist is near the construction site) to do the veneering there. We Do Not Veneer

We always recommend using your local veneering professionals for custom veneer doors. We do not provide veneer or install it.  It is our policy to subcontract veneering jobs to the best veneering professionals in the USA.

If you offer hot-pressed veneer services or cold-press veneering to your clientele, your highest paying customers will gladly pay you more if your panels have Sing Core inside.

Hot-pressers Are More Successful and Profitable with Sing Core.

If you are a veneering professional, then we would like to work with you! Please contact us, we have plenty of veneering jobs to subcontract out.

For standard sized doors, we send our premium substrate to veneering professionals near the job site to be hot-pressed.  If the doors are very large, we may have the veneering professionals prepare the veneer for us to cold-press in our facility.

Let’s face it, nothing can compete with the beauty and elegance of a perfectly hot-pressed panel, and for that sweet-spot in the marketplace, those clients that demand the best and are willing to pay for it. The manufacturers and millworks that have Sing Core inside their hot-pressed products are making bank by specializing in these ultra-high-end projects.


All Sing Panels are packed fully insulation, custom manufactured to architectural specifications in our Pacific Northwest factory, they can be made of any flat building material, in any shape, and any size (up to 50 ft.) are lightweight, high strength and Premium Sing Panels can be guaranteed to stay warp-free for 50 years. See Insulated Aluminum Panels

Large Production Runs

Sing’s factory is setup to do large production runs for all types of doors, including stile-and-rail-style doors, at a fraction of what it would cost a busy door factory to setup and retool for a large quantity order. The biggest door companies in the world rely on Sing’s factory to do the “heavy lifting” on their large non-standard-sized door orders, saving time and money.

Team Support

Our true flat team can help you to engineer the panels you need to achieve the results you want to deliver to your clients without compromising the integrity of your design. Years of experience with our patented material and patent-pending warp-prevention technologies can be a valuable resource to you and your team.

50-Year Warp-free Guarantee

One of the most important characteristics of Sing Panels is their ability to remain straight and true without added support. Even long spans can be covered with very little deflection, even under significant loads. Due to Sing Core’s ability to cover long spans, this characteristic is key in our ability to make warp-free doors of any size, of any material, in any style that can be guaranteed not to warp, bend, twist or otherwise fail for 50 years. Large doors (over 8 ft tall) do not have a warranty because everyone know they will fail due to warp, that is, unless they are guaranteed not to warp due to their having specified, “Sing Core inside.”

Sing offers the only 50-year guarantee that your doors will not warp, bend, twist, or otherwise fail (including structure). If we couldn’t do it, you would not be reading this statement now.

How Do You Do It?

Sing Sandwich cutaway exposing patented Sing Core

Torsion Box/Foam Core

Peter Sing, the inventor of Sing Core, developed a hybrid building material of old and new technologies leading to this new approach to dealing with the issues concerned with weight and strength. Basically, the base structure is vertical grain (much stronger than horizontal grain) torsion box filled with recycled rigid foam insulation sandwiched between two stress skins using formaldehyde-free adhesives.

The result is nothing short of a breakthrough in building materials making creations more possible in the real world.

How Can We Best Help You?

1. Paint Grade
2. Wood Grain
3. Metal
4. Quantity Orders
5. Untrimmed (Save $)

We long to work with our architects to solve the problems associated with size, weight, strength and insulation. Submit a request to open the dialogue with our staff to receive your free large door consultation. You will receive a response from our team within 24 hours.

Increasingly, we owe a huge debt of gratitude to the architects who support us in the substitution space. We are honored to help provide the best affordable solution to meet or exceed the long-term expectations of your clients. If your project has not been completed, there is still a chance that we can help you with the substitution process.

Design hint for weight, strength and flatness of Sing materials

We are able to accommodate the weight and strength you are looking for in your design. For instance, an average 2 inch thick door weighs from 1 to 2 lbs. per sq. ft. It is easy to attain adequate strength even if your designs are sleek and thin.

Other types of core requires enough thickness to achieve a certain strength, such as core materials made of paper, plastic or low grade aluminum honeycomb core. If it is large panel or large door plank then we need to know your desired tolerances for true flatness. We routinely build 20 ft. tall doors as straight as following a straight line, by using Premium SingCore inside large doors otherwise we be able to target within your individual requirements.

Sing Core exceeds current code requirements. For example, in the door industry, AWI’s guidelines dictate that a door should be less than ¼ inch flatness. Sing Core routinely builds doors that are over 10 ft or longer in length, yet exceeding those 7 ft doors code requirements. Doors made of Premium Sing Core provide 50 years of structure and warp-free warranty. (As a common practice in door industry, most manufacturers offer only a one year warranty.)

Products made with patented Sing Core can be easily repaired without compromising it’s original strength, due to the structure of Sing Core and the bonded stress skin which when compared to solid wood and other types of solid materials would pose a significant challenge.

Insulation: Sing Core has built-in insulation value with an R3 to R6.5 rating per inch, depending on client’s needs/specifications.

Sound deadening: Sing Core’s filler material has natural sound-deadening properties. Other sound-deadening options are available at customer request.

Light weight: When compared to other materials Sing Core weighs much less, as much as 50% less, or more, as little as 4 lbs. per sq. ft. yet eco-friendly. This advanced technology used in the aviation industry is now available for use in your home.

Strength: Sing Core based on 2″ x 2″ grids and 3/4″ thick = 660 PSI. For instance, aluminum 3/8″ grids = 30+ PSI (smaller grids should be more strength). Sing Core’s superior strength comes from its advanced torsion box design.

Solid: Sing Core is solid like a rock. While the vertical wood grain torsion box core may be compared to other hollow honeycomb cores, the Sing Core voids are not hollow as they are bonded wall-to-wall and filled with recycled foam for a strong, solid substrate.

Eco-friendly: Sing Core is manufactured using natural wood fibers, no formaldehyde, or toxic chemicals, is created using less energy than any other core material with little or no waste.

Renewable: The structure of Sing Core is 100% renewable (nature-grown) clean fiber and/or recycled material.

Oversize: Sing Core excels in area of large oversize products due to its unique properties and can be up to 50 foot length.

Dimensionally stable: Sing Core is the most dimensionally stable building material allowing us to create large, oversize products (i.e., doors, up to 50 ft.) that are true flat exceeding AWI standards and can be guaranteed to be true flat. Large oversize panels can be truly dimensionally stable without any movement due to temperature and moisture change.

Affordable: Even though Sing Core technology is used in high-end applications, we make it affordable for broad use in a large number of applications. Sing Core performance is comparable to any high-end core but could be as little cost as low-end wood product core.

Waterproof upgrade: Sing Core is available in waterproof upgrade, to accommodate your specific water resistant requirements.

Fire retardant upgrade: When used in fire retardant applications, the Sing Core fire retardant door is the lightweight, super-strong, eco-friendly alternative.

Bullet-proof upgrade: In high-security end products, most cores used in bullet-proof applications are heavy in weight, causing strain on the infrastructure, unlike Sing Core.

Thickness available: Sing Core is readily available in many thicknesses, up to 6 inches in standard thickness, with custom thicknesses available.

Skin options: Available in many different exteriors including (but not limited to) aluminum, cement board, cold roll steel, concrete, ceramic tile, fiber glass, galvanize metal, glass, MDF, metal, plastic, plywood, solid wood, stainless steel, etc…

Easy to machine: Sing Core is easy to work with in the shop or on-site for sawing, sanding, adding solid wood implants, gluing, cutting and fastening.

Fast turnaround: In you’re in a rush, only Sing Core can be custom made within 24 hours and is proudly manufactured for you in the USA.

Sing Core’s mission is to provide superior eco-friendly product to architects share a common goal with Sing products; to build a better World creating a healthier, green planet, benefiting all creatures and life forms for extended sustainability for the future.

The Sing Non-warping Solution

The science behind the patented Sing Core technology specializes in providing non-warping solutions for a wide variety of Skin Options, including (but not limited to):

The science includes composites that counter the effective influence that certain materials have in tendency to move according to moisture or temperature variances on either side of the panel.

“There’s just no other way to do it.”

Client List

Product Expectation

It is important that you understand the condition that you will receive your Sing product in. All Sing Core product (unless otherwise custom specified) are delivered unfinished. They are unfinished paint grade, pre-sanded to 60-Grit which is not paint ready, though Birch skin is smooth but not ready for paint.