splines for barn door planks

[Lynn Kasdorf]

I'm building a sliding barn door that is 9' wide and 10' tall. I'm using 1x12 eastern white pine. The door is semi-exterior- it is under a shed roof so it is mostly protected from the elements, but it occasionally get a little rain on it during windy storms.

This wood is apparently kiln dried, and was delivered to the lumber yard just last week. They call it barn board- planed on one side and rough sawn on the other.

So hopefully it won't shrink too much. However, I'm sure there will be some movement. I'm thinking that I'll cut a saw kerf width spline about 1/2 or 3/4" deep on the edges and cut splines out of some 1/8" plywood I have. I plan to leave the splines unglued. Or perhaps I should glue one side. I'd like to avoid big gaps between the planks as they shrink.

The construction of the door will be this: The boards will run vertically with the spline between them. I'll border the door and run an X brace out of 1x6, so this should keep them farily well in a plane, and the splines should help. When it is all done, it will get painted barn red with white border and X. I wonder if I need to coat the inside in order to equalize and minimize cupping? This is in an uninsulated section of the barn, so I don't need to worry about insulation.

Anybody have any comments/suggestions about this plan?

[Jamie Buxton]

The splines sound like a very good idea to me. Regardless of the delivered wood moisture level, they're going to grow and shrink while they're out in the weather.

1/8" plywood seems too thin to me. In addition to being a visual shield, the splines are going to be a mechanical connection between the planks, trying to keep them somewhat connected while warpage tries to made some of them curl up. I'd use 1/4" ply, and cut the kerf with a slot-cutting bit in a router.

...come to think of it, trying to cut any edge-kerf with a table saw on a 10'-long board would be a wrestling match for me. The board is long enough that it'd be getting away from me, one way or another...

[Paul Libby]

I would go with a 1/4" spline. And yes you do need to coat/paint both sides, edges and ends of the boards to minimize movement/cupping. Sounds like a fun project.

[Lynn Kasdorf]

I have a bunch of 1/8" plywood, which is why I figured it might be a good choice. But, it probably should be thickerer.

And I have thought about do it with a wing cutter in a router, although the boards are very straight, and I have finger boards to force them against the fence. But a router will probably be easier.

So- what spline material- I think I have some 3/16" or 1/4" plywood, or I could cut splines from white oak, of which I have a LOT of scrap of as a result of residing the barn. I can rip splines on the TS or the big ol' band saw with the carbide blade. Ply would be easier, but the oak would be stronger.

Maybe I'll coat the inside with polyurethane or BLO/poly/turp in order to seal.

[Jeff Horton]

Just cut a rabbet on opposite sides of each board. Then let the rabbets overlap each other when you put the boards together. A 1/2" rabbet should be adequate for any movement you have. And you don't have to fool with cutting and assembling the splines. And yes, I would paint/seal both sides!

[Frank Fusco]

Barn door planks are supposed to shrink and show spaces in between. I think it's a law or something. ;)
Never saw a decent barn door that didn't have cracks in between. Just wouldn't be right without the cracks. :rolleyes:

[Paul Libby]

If white oak is an option for the splines, use it. It will not delaminate and is rot resistant.

[Ben Grunow]

Any way to make 2 smaller panels that float in a frame like a large cabinet door? Then you could glue all the boards together (still use splines or biscuits) and paint them and the whole panel could grow and shrink and go unnoticed. Maybe a pair of 1x6 frames with a 1x4 frame sandwiched keeping the outside edges flush to create a 2" rabbet around all edges. This would thicken the doors and require more careful bracing but that wood is likely very light weight and a barn door can handle a metal strap brace without looking out of place. Just a thought to keep the wind from blowing through the gaps. Let us know what you decide.

[Rick Levine]

I am starting a similar project in a couple of months, when my shop is finished. My door will be roughly 6 feet wide and 7 feet tall. I plan on using Pondersosa pine since it is readily available here plus it has been used in this area for hundreds of years.

The splines are a good idea I may incorporate them in my door. Or I may use T&G with dowel plugs, I haven't decided yet. Instead of paint though I'm going to use Penofin. It's a marine oil wood finish which should hold up better than paint. Besides I want to show the grain of the wood rather than covering it. It is more the style here in New Mexico and my house anyway.

This is a rendering of the door I plan to build:

http://i9.photobucket.com/albums/a75/ricklevine/door.jpg

[Charles McKinley]

Hi Lynn,

How about a 1/4X 2 inch batton nailed over each of the seams?

What I would have given for a brad nailer when we did this on my little house when I was in the Peace Corps.

I also like Jeff H's rabbet sugggestion.

[Rick Cabot]

Lynn
I recently completed a similar project constructing large barn doors. I simply shiplapped all the board edges and then bolstered them together; construct the door with a top and bottom section of equal sizes and tie them together with a central piece and an outside frame. Use onlay cross braces on the inside. You will definitely need to paint/ and or seal the inside of the doors if you are planing to paint the outside as twisting, cupping and separation will quickly become an issue. Good luck with the project.

Rick Cabot
Dover-Foxcroft, Maine

[Lynn Kasdorf]

I think I'll end up doing the rabbet approach. Basically, I have so much work to do on this barn, that I can't obsess on individual projects like this.

I may actually get rolling on this today. As the nights get colder, I am really wanting to close up that 9' x 10' opening!

Currently I am patching the 2 layers of oak flooring with scraps from the siding project. I had to replace the entire ground level sill beam the high side of the barn, and in the process I removed a couple feet of flooring the whole 65' length of the barn. On a 150 year old barn, nothing is plumb or square- so trying to get a reasonably even floor with minimal tripping points is very tricky. Whole lotta cutting of shims and wedges...

Cheers