There have not been many truly significant advances in the manufacturing or pivot doors in the last hundred years, until now, with the invention of patented Sing Core which offers the only pivot door 50 year guarantee for a large custom eco-friendly lightweight high strength door.

Such a door could not be built before. In fact, when the largest door companies were approached with building a large custom pivot door, they turned the job away, because while such a door could be built and look spectacular when installed, it would not be long and the door would fail.

Large custom pivot doors were manufactured by high end millworks willing to do the work and charge the prices commensurate with a high degree of craftsmanship with reliable regular maintenance over the life of the door because the key to making these large pivot doors work over time would require a heavy maintenance schedule to straighten the doors that were known to warp and need repair periodically (potentially every change of season depending on the climate and geographic location of the big pivoting door).

This was the case of every large pivoting door over three-and-a-half feet wide and seven-and-a-half feet tall, especially if they were large wooden pivot doors. Natural wood tends to want to move according to any change in the environment. The result? Large warping pivot doors.

Enter inventor Peter Sing’s patented large pivot door core which empowers high end millworks and the biggest door companies in America to build the biggest lightweight high strength pivot doors in the world that can be

Guaranteed Warp-free for 50 Years

Inventor Peter Sing created a hybrid composite core and anti-warp technology to build large pivot door cores that could support the weight of any exterior material and stay straight and true. Sing’s True Flat Team helps to design and create the perfect door base material to accomplish the goals of the architects, designers, door engineers, artists, and end users, with no risk of warping doors.

The technology is based on a melding of new and old technologies using Sing’s out-of-the-box approach to problem-solving. Start with a basic torsion box design (traditional method of building large flat wooden products) but flip the grain of the torsion box frame on its side so that it lays perpendicular to the stress skins. Then before you apply the stress skins fill all the empty cavities inside the torsion box structure with rigid recycled foam. Cold-press with formaldehyde-free glue for a basic warp-free base material.

That’s the basic formula, but there are type of woods and other building materials which have a greater propensity to warp than others. Sing’s True Flat team reviews each door and determines if extra patented and patent-pending anti-warping technologies will have to be added to the door to keep it from warping, especially if it has a surface material with a greater potential to warp.

The Warp-free Pivot Door 50 Year Guarantee

Is a science which Sing has mastered. And just when you thought that might be all you might expect from any pivot door with Sing Core inside…

But Wait. There’s More…

All of Sing’s pivot doors also have an impressive list of features that you would be hard-pressed to find anywhere else, except for Sing’s factory located deep in Washington State’s scenic Pacific Northwest. They also offer,


For added safety and security for you, your family, at work, in scientific, government, and military applications. This is why you see Sing’s core specified in the best soundproof doors.


At least R3.5 per inch (R-value can be increased to match your performance expectations) of Sing Core give’s you more separation from the elements or greater temperature control in heating or cooling environments.


If you are looking at a lightweight high strength building material, Sing’s core can meet or exceed your precision expectations as it hosts high tolerances throughout (+/- .006 in.).


In side by side comparisons, pivot doors with Sing Core inside require less maintenance over time than any other door because, simply stated, they do not warp, cup, bend, twist, not otherwise fail.


Sing’s doors are designed and built to last for centuries but guaranteed to perform fail-free for 50 years. No other eco-friendly lightweight high strength material can do that.

Add to those characteristics, the following attributes:


A fraction (at least one-third less) the weight of other wood-based cores or their alternatives.


Able to span long distances and carry loads with little or no support. Unbelievable unless you’ve had the opportunity to handle a Sing door first-hand.


No other material can compare to Peter Sing’s uncanny ability to build doors that just will not warp. Sing Core is the reason door companies, millworks, and custom door manufacturers are back in the business of building large pivot doors again.


The only door in the world guaranteed not to warp, fail, or delaminate for 50 years.

This is why more and more you are able to find Sing’s patented tech anywhere from beneath the sea (US Navy) to outer space (NASA) and everywhere in between.

Join the Sing Revolution today, for a better world.