Don't Forget the Radius!

 When sending in drawings for pricing or engineering it is important that we have the overall dimensions, on center spacing, and desired layout for your project. Another important, but oft forgotten, dimension is the radius!

When doing a project with curved beams, knowing the radius can make all of the difference. We do not use heat, steam, or water to curve our beams, just the force of our pneumatic tools and the right ply thickness. In Part 2D of our "Glulam Building: Start to Finish" series we talk about some rules of thumb when it comes to radii.

At the plant right now we have some projects that really illustrate the impact radii can have on a glulam project. 

Here is an example of a Tudor Arch with a 3' radius. It requires 68 1/4" plies to create a maximum depth of just 17"! Compared to a 20' radius that requires 13 plies of 2x material or a 7' radius that requires 26 plies of 1x material.

Starting to clamp a 3' radius arch. Arch clamping always begins at the deepest
point, then is bent in both directions from there.

Tudor Arches with a 3' radius and 1/4" plies.

You can see that it requires a lot of pieces and a lot of glue to achieve such a tight radius. Below is an example of a Tudor Arch with a 5' radius. At 5' we have to use 1/2" plies. While slightly better than the 3' radius a 5' radius still requires extra handling to get the 1x material down to a usable ply thickness. These arches have 55 plies creating a maximum depth of 27-1/2".

Tudor Arches with a 5' radius and 1/2"plies.