Entry Door Construction

[fRED mCnEILL]

I've looked at various door construction techniques on the Creek and know there usually is more than one way to "skin a cat". Currently I've built an entry door using 3 laminated layers of the same wood. Overlaping at the stiles allows you to have large tenons and it makes for a strong door.
I've also looked at the method of laminating the rails and stiles for the core in butcher block fashion and then laminating 1/4 in veneer to the outside with all -thread used in the construction.

I am planning to build a door using red cedar that has a solid tongue and grove appearance. I was thinking of using 3/4 in or 1 in plywood as the core and laminating 1/4 inch cedar in a tongue and grove fashion on each face..

Does anyone have any experience in this type of construction. I think the core would be very stable but wonder what happens with movement on the outside layers or would this not be a problem because it is realtively thin?

Thanks

Fred Mc.

[fRED mCnEILL]

Anyone have any suggestions?

Thanks

Fred M

[Jim Becker]

Fred, I suspect that the two doors in the 250 year old portion of our home were built in a similar fashion with T&G and improper cross grain situations...and they are splitting horribly. So much that next year I'm going to have to replace them. They were apparently build by a carpenter who combined materials with no real understanding of wood movement. I would not suggest you use a manufactured product like plywood as your core with solid stock overlaying. You are setting yourself up for major problems. that way. If you want to use the T&T cedar for it's look, then use cedar (or another species with similar movement factors) for your core. The exception to this would be if you veneer with material that is somewhat thin...say, 1/8" or preferably less. The 1/4" material you want to use is thick enough that movement will be a factor for sure.

[William OConnell]

If you use plywood as a core your more than likely going to have some warpage problems. I use LSL which is linear stranded lumber but some use standard stave cores.
Heres 4 boring videos of core construction
http://video.google.com/videoplay?docid=4406564055255336961&hl=en
Heres the doors in progress with the skins applied

http://woodworkers.us/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=866&g2_serialNumber=2&g2_GALLERYSID=b1d61effcb6f8f22596283811ff3d166
Here they are at the customers home
http://www.indianisland.us/Gallery/main.php?g2_view=core.DownloadItem&g2_itemId=1658&g2_serialNumber=2

[Howie Bernstein]

Hi Fred,

I started a thread here (http://www.sawmillcreek.org/showthread.php?t=97240) asking about making a wine cellar door. My original plan was to use different woods for the interior layers, mostly because the wood I have (leftover from deck construction) and planned to use for the exterior layers is Ipe. However, reading this thread it appears the use of different woods, unless maybe LSL, isn't such a good idea.

I was wondering if you built the three-layer stiles and rails first, or if you constructed each door layer separately, and then bonded them together. Any other advice you can give (here, or over in the other thread) would be greatly appreciated. Thanks.

Howie

[Brad Shipton]

I agree with William that using plywood will make it tough to get the doors perfectly flat. I would start with a test run first.

From your description it sounds like you have researched traditional stave core construction (stiles/rails), but you intend to apply veneer strips (with edge easings) to a sheet of plywood making this a ledger style door (no panels)? That will be a fun veneer glueup. To make sure the grooves show, it seems you are stuck with 1/4" veneer or thicker. Stability wise, 1/4" seems to be pushing the envelope of what most use. I know of a few using 3/16" skins for doors stiles/rails to allow carvings, but most veneer guys come back with 1/8" as a max.

From your description it sounds like you are aiming for 1.25" to 1.5" thick. I would stick to a standard 1.375" or 1.75" or find the hardware you want before you start the project.

Good luck.

Brad

[Peter Quinn]

Plywood has great shear strength, or the ability to resist forces across its width or length when properly secured, like sheathing. It has plenty of strength for cabinets because it is joined at right angles to creat a rigid box. But it is fairly flexible and prone to warping over its length and over any great span unsupported. I doubt using it as a door core would meet with any success unless you could rip it into 1" strips and glue these strips face to face to great a glue lam type stave core as a substrate .

You could build a ladder frame and skin it with plywood as your substrate, sort of like your own very solid almost hollow core door, then apply your veneer over this. Might work with 1/4" material though conventional wisdom suggests otherwise, certainly a possibility of failure.

One of the guys at work made some doors similar to what you are describing using 3/8" QSWO T&G with V bead, assembled to look like a slab door using this type of ladder frame minus the plywood as a substrate (1 3/4" final thickness). He glued the two outer most boards to the ladder frame along their entire length, the field was glued only top and bottom at the center of each board, silicone was used to connect the frame to the middle of the length of these boards. They seem to be surviving well to this day, I think he made two dozen for a client in this manner, some with a different wood on each side of the door. Unusual construction, but possible.

[fRED mCnEILL]

Howie, I built the door as per an Article in Fine Homebuilding(Jan 2005)by Scott McBride.

It is a 5 panel door. Each layer is built separate and then glued together. By doing it this way you can extend the stiles of the centre layer into the rails which in effect makes large tenons. The 5 panels are 3/4 inch plywood held in with molding. Each layer is constructed using pocket hole screws.

The author claimed it was especially good for large doors i.e..

I built mine using straight grained douglas fir.