When you spend $10,000 to $100,000 on a door and it warps, can you fix it? No.

It may be a beautifully and skillfully handmade door, but if it is warped, it fails to function as a door to any level of satisfaction.

These expensive doors are made with solid materials or core substrate material which is the weakest link. The core of the door determines the weight, strength, and long term performance of the door. Only doors with patented and patent-pending Sing Core technology inside can be guaranteed not to warp or fail regardless of size, exterior surface material used, or style of door for 50 years.

“We’ve switched from using LVL door core to Sing Core and no longer have to worry about warped doors.”

While LVL and wood-based door cores are fine for standard sized doors, these are not practical for large doors because they increase the weight of the door significantly making it more apt to fail, expensive to handle, maintain, and even potentially dangerous.

This is why the top door companies, millworks, and custom door manufacturers rely on Sing Core delivering the best door substrate enabling them to warranty wooden and large doors.

Would you settle for a 1-year warranty?

Most doors come with the standard 1 year warranty (large doors may only carry a 30-day warranty, or more commonly, are exempt from any warranty at all) because, as is well known and they say in the industry,

“All large size wood doors warp,”

unless they have Sing Core inside.

Click to see this door with Sing Core inside this $38.5 million-dollar estate


How to build the best doors

Sing door blanks are the best foundation for building the best doors. The Sing American French Door is revolutionizing the American modern door industry. Using Sing door blanks adds unparalleled core value to your doors; with it any size of door can be built that will not warp, bend or twist.

The technology that enables door manufacturers to build Eco-friendly lightweight high-strength doors was invented and is 100% made in the USA.

True Flat and Guaranteed not to warp for 50 Years!

With our professional doors, we can guarantee they will not warp, bend, twist, or otherwise fail for 50 years, including full structure warranty.

No Joke

Sing Core has been offering this 50-year guarantee to high-end door makers for years. In the event we were not able to deliver these results to our clientele consistently over time, we would not be continuing to serve the biggest and best door companies in the United States, and we would not be able to offer such a guarantee.

Guarantees are offered with doors which are covered, in writing, signed by the inventor of Sing Core. We take our 50-year guarantee very seriously. Our best clients depend on this worry-free performance and trust us to provide them with the best solution for large doors of any size or style.

Want to know more? Click here

What makes the best door in the world?

With Our Free Consultation Premium True Flat Doors are Guaranteed Not to Warp for 50 YearsThe best doors:

1 Highest precision

Within +/- .006 inch tolerance door core. No other core can be built with this high precision. This close tolerance means better bonding which  provides the ultimate strength while being visually pleasing.

2 Non-warping

No recall problem with perfectly straight doors even doors made of wood.

In fact, SingCore offers a 50 year true flat door guarantee on professional doors. No more warped doors.

3 Strongest door

Solid insulated reinforced torsion box technology sounds solid, no rattling noise for superior strength. If you kick a Sing door, you will break your leg.

No rattling noise while closing door.

Professional Sing doors are guaranteed not to fail for 50 years.

True Flat Guarantee premium certified true flat4 Lightweight

An average door weighs approximately 1.5 lbs to 2.5 lbs per square ft. – even a 16 ft tall door! The best lightweight doors with the greatest strength that do not warp.

5 Insulated

Up to R-6.5 per inch.

Sound deadening could reach STC 56 or more.*

Highest fire-rating if necessary (by custom design and independent test to meet custom specs).

PICT0430-16 Custom lite openings

Any size and shape of light cut out within minutes ready for glass installation

7 Any type of door

Sliding door, pivot door, French door, carriage door, pocket door even exterior door (click here to see wood door 100% exposed to the weather)

8 Any size door

We are able to supply 20 ft tall Sing door panels to mill works and door manufacturers to build true flat doors that are true flat and guaranteed to stay flat for 50 years; even large oversize doors.

9 Any skin

Available in any exterior surface material: paint grade, wood grain, metal, (Aluminum, steel, copper, FRP, Cement, ceramic, Gramite, HPL, Kevlar, LVL, MDF, Steel, Veneer, etc.)

10 Increase production

Using sing door core provides high productivity for high end door makers. We offer OEM service for door manufacturers by providing 6000 pieces of Sing panels per month to build the best doors in the world. Use SingCore to help you Win the Bid.

New and Improved Large Sing Doors

Our most recent developments include our highest performance large door solutions yet. Take for instance our most precision lightest weight and highest strength large wood pivot door that is not only true flat but guaranteed to stay flat without warping, bending or twisting for 50 years!

12 ft x 10 ft wood pivot door lightweight high strength non warping 50 year guarantee

This large wood pivot door is 10 ft. x 12 ft. and perfectly flat. Now, wood is normally a problem for any door, especially a large door, but used in conjunction with SingCore door technology, we have taken large pivot door technology to a whole new level.

Sing Core Panel Watertight Church Door

SingCore Panel Watertight Church Door

How can I get the best door in the world?

You can specify that your door be manufactured with SingCore Inside by any of door company, millwork, or custom door maker.

If you are designing your own high-end door you can have it custom manufactured by your local millwork being sure to tell them that you desire, “SingCore inside.”


You can sleep better at night knowing that you’re working with a revolutionary Eco-friendly building material that helps to make the world a better place for all Earth’s creatures.

If we can solve your problems associated with and provide you with the very best very large front door, entry door, hinged door, sliding door, pivot door, trade show displays, and museum walls, we can potentially help you create just about anything with this same high-end performance.

Doors Built with SingCore Inside

* Note: STC rating varies according to size, thickness, skin, and other factors. Sing Core does not rate doors, although we are fortunate enough to have one of the best sound testing labs in the world, here in the Pacific Northwest. If you require a specific STC rating, Sing Core can build a door to your architectural specifications and have the resulting door tested at our rating facility for an official rating.