When your beautiful new Sing Core door sections arrive, it is important to take the time to glue the door together properly. Although Sing Core panels are guaranteed warp-free, we cannot guarantee work done on site. Failure to properly follow these directions may result in a poor final product.

Sing Splines Don’t Crack

Sing Core uses our patented core material as a spine to join several panels on site. Unlike solid wood, the stability of the core material means that there is no danger of cracking or splitting of the seam at the join location.

Join on Site in Three Steps

1. Lay Door Panels Flat

It is very important that all panels are laid flat on the ground and are completely level. Attempting to glue the pieces up against a wall or other than completely flat may result in a crooked joint and a “warped” door.

The first step to join a Sing Core sectional door is to lay the panels on a flat surface. Any flat clean surface will work. For very large doors we like to use two straight beams laid on the ground along  to hold the top and bottom of each door segment.

2. Slide a Spline in to One Side

Each spline and pocket are precisely cut to fit with strength. Our products are built with our warp-free guarantee in mind. Simply push or lightly hammer the spline in place on one side of the joint. Then your panels are ready to be fit together.

3. Joining the Panels

The final step in joining a modern sliding or pivot door is to press the sides together. This can be accomplished a variety of ways, including gentle application of a sledge hammer, a few ratchet straps, clamps, or any other means you have of providing joining force. Once joined, the door is strong and secure, built to last, and can be finished and installed as any other Sing Core door.

Joining in Action


How to Clamp at the Join

When you want perfect alignment for very high tolerance applications, it’s best to sandwich each joint with a straight guide temporarily during the gluing process.

In order to make your process easier, Sing Core offers construct custom true straight guides for your application and ship them with your order. These guides are made with the same high precision core material as our other products and offer superior ease and performance.

Specify you would like clamping guides when you place your order and we will gladly include them for you.

Sing Beam

If you have a very wide and large door, you might consider ordering a straight Sing beam to keep the top and bottom of the door in process perfectly straight in addition to the temporary guide to make sure the door perfectly flat the entire length.

Let us know if you would like sing beams added to your order and we would be happy to oblige.


The flatness of your door depends on how flat your sections are when they cure. Any warping in the mold will be retained once the glue drys, so it is vitally important that you clamp up your sections precisely straight.