Ian Sage No Comments

The Troubles of Warping Doors and the Sing Core Solution

Doors are an essential part of our everyday lives, providing security, privacy, and aesthetics to our homes and businesses. However, a persistent problem that many of us have encountered is door warping. In this article, we will explore the common issues associated with warped doors and shed light on how Sing Core doors offer a revolutionary solution to this age-old problem.

The Problem with Warping Doors

Warping is a natural phenomenon that occurs when doors, typically made from solid wood or other materials, expand or contract due to changes in temperature, humidity, or poor manufacturing techniques. As a result, the door may twist, bend, or bow, leading to misalignments, gaps, and difficulty in opening or closing. This not only compromises the door’s functionality, but also affects its appearance, causing a lack of visual appeal and reducing the overall value of the property.

Traditional solutions such as reinforcing with extra material or bracing can provide temporary relief, but they often alter the door’s aesthetics and fail to address the root cause of the problem. Homeowners and business owners alike have long sought a more effective and durable solution to combat door warping.

The Sing Core Difference

Sing Core doors have emerged as a game-changing solution to the persistent problem of door warping. Developed using our patented techniques, these doors are constructed using a unique honeycomb core that combines torsion box technology with a lightweight, rigid foam core.

The secret to their success lies in the Sing Core’s patented honeycomb core. This creates an incredibly resilient and stable base which is not only warp free, but also incredibly strong and durable. This innovative construction technique ensures that Sing Core doors remain flat and resist the effects of temperature and humidity changes.

Additionally, the lightweight core minimizes stress on the door, reducing the risk of warping altogether. By using this advanced composite material, Sing Core doors achieve remarkable structural integrity without sacrificing weight or compromising on aesthetics. In addition, every Sing Core door comes with a 50 Year Warp-Free and Structural Guarantee, so you can trust that you’ll never have to worry about your door warping on you again.

Benefits and Applications

Sing Core doors offer a range of benefits to homeowners, architects, and builders. Firstly, their exceptional stability means that they require less maintenance and repair over time, saving time and money. Secondly, their lightweight nature allows for easier installation, reducing labor costs and effort.

Sing Core doors are suitable for a wide range of applications, including residential homes, commercial buildings, and industrial settings. Whether it’s an interior or exterior door, Sing Core offers customization options to suit various design preferences and project requirements.


Warping doors have long plagued homeowners and businesses, compromising functionality and aesthetics. However, the revolutionary Sing Core technology provides a much-needed solution. With their unique construction and resistance to warping, Sing Core doors are a reliable, long-lasting investment, ensuring peace of mind and adding value to any property. Say goodbye to warping doors and welcome the stability and durability of Sing Core doors.

singcoreadmin No Comments

Current Trends Don’t Wait

This is an update to let you know what the current trends are, here at Sing Core.

The biggest trend is this:

Warped Doors… Help!

We have been getting a lot of calls from professionals who have installed large doors who are now in trouble because those doors warped. As you know, Sing Core is the only way to build a large door that does not warp, and we guarantee it for 50 years.

If you are in trouble and need that door right away, we can do it for you, but you will incur rush fees. You will be far better off by getting the door assistance from Sing Core in the first place.

Don’t wait. Let Sing Core save you the headache, lost time, and expense of having to replace that high-end door later. According to the reports of incoming requests, the large doors are having to be replaced within six months of the job’s completion. Don’t let this happen to you.

We Can Do It

When you work with Sing Core to help you make that big door, you are working with inventor Peter Sing’s True Flat Team that knows how to build warp-free doors. They have years of experience with all types of building materials and types of doors. They know what can be done, what cannot be done, and have patented and patent-pending technologies to make an otherwise potentially warped door, warp-free guaranteed.



Ordinary vs. High-end

This is the difference between an average door and a high-end door: Precision over time. Out of the gate, Sing’s door core sports +/- .006 in. tolerance which is the highest precision door core to start with. That’s not including all the anti-warp technologies that are available to the team to make sure your door does not warp over time.

Built to Your Specifications

We can solve the issues that you are facing with your door. We can make the door lightweight, no matter what the size, but if you need to match a weight requirement, we can help you achieve that as well. Your door with Sing Core inside can be built according to your specifications.

Some Other Trends We Are Seeing

Grooved Doors

Architectural doors with horizontal grooves appear to be all the rage. If you have been doing this for a while, you already know that routing kerfs, plow cuts, furrows, or V grooves is compromising the door’s structure and may lend to increasing the door’s tendency to warp, but not if it has Sing Core inside.


High precision 1/16″ groove in 1/8″ skin

We can pre-cut grooves, even deep grooves (we have a special process for extra deep grooves) for you, without jeopardizing your non-warping guarantee. If you are doing a high-end job, you should start with a high-end core, like Sing’s warp-free door core.

Curved Doors

Unlike arched doors, curved doors must be very exacting to match the curve of the structure in question. The last thing you want is for that door to move, rendering the door unusable. This is extremely important for curved doors, that they keep their shape consistent over time.

Sing Core can match any curvature in your perfectly curved door and guarantee maintaining is shape in longevity. Nobody else can do that and guarantee it for 50 years.

CNC Carved Doors

CNC carved doors are really being seen as on the increase. These doors can be rather large, and you will need enough wood (meat) to carve into, and there are varying landscapes being carved into the grain, which is an invitation to warpage.

To prevent future warping doors, these CNC artisans are making sure they have non-warping Sing Core inside, specially designed and reinforced to accommodate both the natural wood grain and the varying depths being carved throughout the door’s surface area.

How Can We Do It?

How can we consistently make the doors that are impossible for other door manufacturers to create? Because it’s all we do. We have been doing it for years and will do it for many more.

We are not saying that other companies cannot provide their clients with 50-year warp-free extraordinary doors, because we work with the biggest and best door companies to assure that they can give this level of service and precision to their clients. They trust us with giving them what they need to deliver their best to their best clients.

Let us help you deliver the best big doors to your best clients.


No Comments

Patented Sing Core door substitution trick

We do our best to look out for the interests of the architects we work for and with, but there is only so much we can do. We know how important it can be to work with people that you can trust and we will back you up in any way we can, so exercise caution when working with others on your project.

For instance:

We got a call from the East Coast early in the morning. It just so happened that the owner/inventor picked up the call from an architect in Florida, who reported that six months following the installation of a high-end door with Sing Core inside, the “16 foot tall door was warped,” and that there was an unbelievable “bow in the door,” rendering it inoperable.

The inventor was shocked, “How could this be?”

The architect, as well as the architect’s client, were upset because they had specified and paid for a top-of-the-line door with Sing Core inside that was guaranteed to remain warp-free for 50-years, and here we were only six months in and already the door was not working.

Immediately, Sing Core took responsibility for the condition of the door and set out to find out how exactly such a thing could have happened. We took down all the pertinent details provided by the architect including the size of the door, the exterior wood species which was applied to the door, the approximate date the order would have been placed, the identity of who ordered, received, and installed the door.

Pictures were provided of the door which clearly showed that the door was warped and that it could not be used in such a condition.

We were tasked to find out which team worked on that door to hopefully discover what could have possibly happened during the manufacturing process of the door which might have caused it to fail.

With all our efforts we could find no record of the door being ordered or manufactured, but there was a match. A record of a price quote which was created and sent to the contractor who was named by the architect. No job order, no cut list, no approved drawing(s), no order for materials, no bill of lading.

This shed a great deal of light on the concerns of the architect and his client, for it turns out, no 16-foot-tall door was ever made at our factory for this project.

The door which was installed by the contractor and paid for by the client clearly did not have Sing Core inside. Any door of that size with natural wood grain on the surface would warp. That’s why people rely on Sing Core to keep their doors straight and true.


No Comments

How to Measure a Warped Door

How can you tell if you have a warped door or not?

There is an industry standard method of determining whether your door is warped or not.

To determine whether you have a warped door or not you will need a length of string (longer than the length or height of your door) and a measuring stick or tape measure.

a) Tape one end of the string to the edge of the door and the other end to the opposite edge of the door.

The string should be straight. If there is a gap between the string and the door’s surface, you may have a warped door.

b) Measure the gap between the string and the door’s surface area.

If the gap is greater than ¼” your door is warped (according to AWI standards for 1-3/8 to 1-3/4 inch doors 3’-0” to 3′-6″ x 7’-0”).

c) If the length exceeds 7 ft. AWI standard applies to any 7 ft. section. Apply string to any 7 ft. span.

Contact your door maintenance company and send them two photos.

d) [1] Photo of the length of the string which shows as much of the door in its entirety, or at least from one end of the string to the other. Then [2] a closeup photo of your measurement of the gap.

Armed with these two photographs, which can easily be emailed to the millwork or door maintenance company of your choice, the recipients will be able to determine how best to approach the repair or replacement of your warped door.

You might consider replacing your warped door with a professional door which has Sing Core inside which can be guaranteed not to warp, bend twist or otherwise fail so as to avoid this pitfall in the future.

For more information, see: Door Warping vs. True Flat

Storing SingCore Doors

After you’ve received your patented Sing products, if you will have to store them prior to finishing and/or installation, try to store them standing upright, on edge, with plenty of space in between, to allow air flow. Do not lean them against a wall. If you must store them stacked, wrap in plastic and place one or two sheets of plywood underneath and on top of the stack of Sing products. This will help keep the entire stack similarly acclimatized while not in use, otherwise, you may have to re acclimatize the top and/or bottom Sing products later, when you are ready to use them.


How to Store SingCore Doors

What if my door with Sing Core inside is warped?

The same standard method of determining and measuring any door with Sing Core inside is used just like any other door (as noted above).

Contact Sing Core about your concerns about your door being certain to include the two photos as noted above.

If you have purchased a professional door with Sing Core inside, you may be the recipient of a replacement Sing door.

Note that upon arrival and un-crating of a door with Sing Core inside, a door may appear warped (and indeed it will be measurable). This is normal for a door which has been packed and in transit. Stand your door on its edge at least twelve inches away from any adjoining surface area, allowing it to acclimatize for up to 72 hours. Measure your door again and you will find it to be straight and true. If not, document for warp (as above) and contact Sing Core.

In the event that a professional door with Sing Core inside is warped (which is highly unlikely) your help in determining the cause of the door’s warping is appreciated. Please assist documenting the chain of custody of your professional door with Sing Core inside, including the millwork or door company which finished the door, and the installers who installed the door, to help us insure your replacement door remains warp-free.

No Comments

Large Modular Non-warping Doors

New Garage Building Material frameless insulated torsion box panels from Lowes Home ImprovementAlways on the leading edge of large door technology, especially in terms of lightweight, high strength and say, “goodbye,” to your oversized warped door forever and enjoy your Sing solution in any size, type or style of door.

Challenges of Oversized Large Doors

When considering a door larger than normal (that might be referred to as an enormous door) many challenges arise for the architects, designers, millworks, builders and installers. Some of the most common problems associated with big doors include:

Warped Door

If the door is taller than seven feet tall and wider than four feet then the door will warp. Warped doors are a common occurrence associated with large doors. This can be annoying for the end user due to the constant maintenance calls required for dealing with the warping door (though it is good for the door service business).

Big Doors Are Heavy

If a door is large you are going to have a lot of weight to deal with. This excess weight causes many issues associated with the building, transporting, installing and maintenance of the door from inception and throughout the service life of the door.

Big Doors are Expensive

Heavy building materials require more time, manpower, resources and equipment to make the door and the result is a big door that is overweight. Heavy doors are expensive to deal with; expensive to crate, ship/transport, offload, finish, store and install.

Overweight doors require more expensive hardware, and the added stress on the frame and the structure requires more regular maintenance over time.

sitting on large 12 ft x 10 ft mahogany pivot door in factoryThe BIG DOOR Solution

Sing Core has been the top-rated guaranteed solution for large doors used by the best architects, millworks and door companies nationwide (see: clients list). In fact, Sing Core can deliver the only Eco-friendly lightweight, high-strength insulated large doors over seven feet tall and 4 feet wide that can be guaranteed to be true flat and stay flat for 50 years.

The only non-warping large door guaranteed not to warp, bend, twist, cup or otherwise fail for 50 years.

20 ft tall large non warping pivot door no more warped door

20 ft. Tall Door

Modular = Newest Development in Large Doors

Sing Core technology has advanced to a completely new level by introducing the modular large doors for combating even more challenges associated with large doors; by creating doors that are shipped as individual components and assembled on-site.

These extremely large doors would cost thousands of dollars to ship (if not impossible due to their large size) but if made in modular components, the large door can be shipped flat-packed and sent by traditional shipping methods reducing shipping costs tremendously. And, the resulting big door can still be guaranteed not to fail!

True Flat Technology Goes Modular

Long known for the largest non-warping doors, Sing Core takes modular huge doors to the next level while still making their 50 year non-warp guarantee. The components are shipped separately and assembled on-site for the biggest doors that can still be fully insulated, operable and manageable without the heavy maintenance required for other big doors. Many connection methods are available for these large door projects including making components using our T Slot Panels as individual components that can be perfectly aligned on site.

Free Large Door Consultation

Of course, building such a door up to 50 feet wide is an art in itself. Each door is designed for its intended purpose. Some of the questions our specialized doors creators ask might include: Will your large door be underwater, in outer space, exposed to extreme weather, need to be bullet-proof, waterproof or soundproof? Also, “What kind of door will you need?” A large sliding door, pivot door, French door or other type of door, etc…

Commercial trade professionals are encouraged to contact us for a Free Large Door Consultation, so that you, your clients and the world at large can know what it is like to own an non-warping large door of any size.

Ian Sage No Comments

Lightweight Insulated Torsion Box Non Warping Door

lightweight high strength engineered plywood exposed torsion box coreThe invention of insulated reinforced torsion box helps woodworkers solve the mystery of warping wood eliminating the problems of warp, bend, twist, cup, cracking and even rot.

Sing pre-built torsion box can be used to manufacture a lightweight true flat workstation. It would take hours – even days – of work to build an 8 inch thick torsion box assembly table that wouldn’t be as strong or straight as Sing torsion box panel.

torsion box animationNot just for torsion box table, the Sing Sandwich panel is a revolution of all paneling and can be reconfigured to any size, shape or dimension, even lightweight structural post and beam.

Buy Sing torsion box panel/honeycomb-panel/Sing-panel to build a butcher block workbench or anything inside your house, outside your house, even your entire house. Floors, walls, portable partition, roof, ceiling, cloud ceiling, etc… See: Applications


The cost is affordable due to mass production made in the USA, patented and shipped worldwide.

This is good news for the woodworker, contractor, millwork, cabinet and furniture manufacturers. Yes, you can even make lightweight, super-strong furniture components.

Lightweight Sliding Door or Pivot Door

Sing Core Panel Watertight Church Door

Sing Core Panel Watertight Church Door

No more heavy sliding doors or pivot doors weighing in at 1,000 lbs. or more. Now you can make a sliding door or pivot door – even floor to ceiling oversized large door – that can be less than 20% the weight of a traditional sliding or pivot door, which means longer maintenance-free performance and less expensive hardware (and less door and hardware repair).

High Precision Accuracy and Solid, like a rock

Your lightweight door can now be solid (not like hollow or honeycomb core doors) insulated, sound deadening, stronger than steel (independently tested at the University of Washington at 660 PSI compared to other high-tech aerospace cores at 10 to 110 PSI). High end architectural millworks enjoy the highest precision building material within .006 inch tolerance.

New generation no fail sliding door 50 yr guarantee50 Year True Flat Guarantee

Say, “Goodbye,” to your warped door. Only patented Sing Core enables door manufacturers to create doors that are true flat (far exceeding AWI standards for flatness) and are guaranteed to stay flat – not warp, bend, twist or cup – for a full fifty years.

Tiny House or Insulated Shed

Quickly and easily erect a tiny house or insulated shed using pre-built torsion box panels (aka Reinforced Structural Insulated Panel RSIP) and never worry about damage of loss due to mold or mildew.

No Comments

No More Warped Door

50 Year True Flat Replacement Doors

Copper Door

Copper Door

Building the most stable door is our specialty. With our patented true flat technology, Sing Core provides clients with insulated Eco-friendly lightweight high-strength doors that prevent wood warping doors. Often we are sought out for replacement doors to solve the problem of doors that fail following installation. Doors – especially exterior, large or special purpose doors – are prone to warping, bending, twisting or cupping.

Why Do Doors Warp?

So many things can contribute the failure or the success of your large door’s performance.

  • Size: Length, width, thickness
  • Skin: Some materials are more prone to warp than others
  • Core: The core material will affect the door’s overall performance
  • Environment: Exterior facing direction, weather, exposure to moisture and/or other conditions.

FREE CONSULTATION for your next large door project. You tell our non-warp experts your door’s specifications and expectations and they can provide you with the only non-warp solution guaranteed for 50 years.

What if you started with a Sing door instead of using it as a door replacement?

Only true flat wood front doors by Sing Core can be guaranteed to be flat and stay flat and stay solid for 50 years. Most foam-filled doors might be straight but need patented Sing Core structural grids to keep it strong and tough to avoid failure following impact or due to exposure. Creating a warp-free large door is a challenge for all door manufacturers because it is almost impossible to make a large door that will be straight and stay straight over time. That is, of course, until the invention of Sing Core.

How can you make the most stable door that can be guaranteed true flat for 50 years?

Sing Core has developed true flat technology that consists of three phases.

Sing-panels-lightweight-high-strength-honeycomb-core#1: Sing Core

The first phase is to start with patented Sing Core as the basis of your true flat door. Sing Core is a composite honeycomb material consisting of natural vertical wood grain torsion box where the voids are filled wall-to-wall with solid recycled foam material that is 90% air. The natural wood torsion box inner frame yields only 8% of this natural resource in comparison to a solid wood door. This provides the strongest Eco-friendly, lightweight door core that will not warp, bend or twist.

#2: Skin Selection

Maple-Cherry-Oak-VG-Fir-Walnut-Sing-CoreThe skin selection is matched to your desired appearance of the door. Do you desire a solid wood grain door? If so, what wood species? Besides wood, we can manufacture a Sing door to host any flat building material, including (but not limited to) aluminum, ceramic, concrete, glass, fiberglass (FRP), plastic, LVL, MDF, Mag-board, stainless steel, veneer, even more custom high-end surfaces like, Kevlar, etc…

Reinforced-Structural-Insulated-Panel-vs-Structural-Insulated-Panel-Sing-Core-vs-SIP#3: Performance Enhancement

Next, our true flat experts review the expected performance and usage of your door. Based on how you want your door to perform and under what conditions, our experts may incorporate additional stress skins to bond directly to the Sing Core base to match your desired outcome. How large are the dimensions of your door? Will your door be exposed to the elements? What extreme exposure, if any, will the door face? Will your door be used: Underwater, in temperature-controlled environments, as sound proofing, to prevent harm to persons or property, etc…?

Any Sing composite door can be guaranteed true flat for 50 years, while matching the appearance of:

Framed Stile and Rail Doors

Weatherproof Church Doors

Weatherproof Church Doors

Also called raised panel doors (when in reality it is not raised panel at all. The appearance of “raised panel” is obtained by graduated cutaways that compromises the integrity of the door). These doors are normally made of several different solid wood (or composite) pieces assembled by dowels or other connections.

True Raised Panel Doors

True Raised Panel Doors

The individual components, connectors and adjoining seams tend to move due to moisture, temperature change or with heavy use or vibration over time.

By examining the red door (left) you would never know that this wood Sing door was not stile and rail yet will last for centuries without fail even though exposed to the weather 100%. The appearance of this door perfectly replicates the appearance of the stile and rail doors that were replaced.

Flush Doors and/or Solid Wood Doors

wood-flush-doorSolid wood doors are a romantic and nostalgic nod to days gone by, but solid wood is well known for bending, warping and twisting due to the natural grain of the wood itself.

LVL is a heavy solid core that is more consistent than solid wood in terms of warp, bend and twist when used in wood doors but will often fail (especially in doors over 10 ft. tall) and once it does begin to move, cannot be stopped or straightened as it has no memory.

Foam Core Doors

Foam core doors such as most FRP door, metal door, etc… are lightweight but have no strength or structural integrity.

Almost any impact will compromise the door causing the door to weaken and/or delaminate, unless it incorporates patented Sing Core structure grid technology.

Break a Leg

Only Sing doors can take the abuse without running the risk of breaking or delaminating.

If you kick a door, it is likely to break; kick a Sing door and you will break your leg.

The Sing Secret

Sing-secret-to-lightweight-high-strength-door-technologyThe secret behind Sing Core’s success is not merely in the torsion box design (which has been used for hundreds of years) but in the orientation of the natural wood grain used to form the grids that are the basis of the internal structure for the patented non-warp base material enhanced by stiffening technology to counter-act potential warp.

In the past, torsion boxes were built with horizontal grain, that while running parallel will tend to fail by bending in harmony with the outer wood skin material. Sing Core flips this technology on its edge by contrasting the orientation of the wood grain to be perpendicular to the exterior wood grain resulting in many times the strength.

Previously solid Balsawood core has been used as door core with perpendicular oriented grain successfully but runs the risk of compromise or failure due to its natural characteristics that will also move due to moisture exposure, climate or temperature change. But it doesn’t stop there.

Next, inventor Peter Sing bonded recycled foam (which is a lightweight solid material consisting of mostly – 92% – air) wall-to-wall inside each void of the vertical grain torsion box grids for unsurpassed shear strength and solid core material throughout.

This is how patented Sing Core has accomplished nearly inconceivable strength in the lab (660 PSI, tested by University of Washington as stronger-than-steel pound-for-pound), yet still remaining lightweight.

All this combined with the Sing Composite Formula for specialized stress skin integration results in the only true flat doors that are built to last for centuries.