Construction Details for a Large Glazed Entry Door
Door builders discuss joinery, hinging, and materials choices for a big, heavy door with five horizontal lights.November 14, 2011
Question
I am going to be building a 2 1/4" x 4' x 8' entry door. The architect has specified a door containing five horizontal lites. The stile opposite the hinges will be 11" wide. The hinged stile 6" wide and all the rails 6" wide. Is this a recipe for failure? I'm afraid that the 6" rails will not be sufficient to keep this door from racking. Is there a ratio for bottom rail width to door width and height? Also, will four ball bearing hinges handle this door or should I suggest a pivot hinge? The homeowner is worried about how difficult it will be to open this door.
Forum Responses
(Architectural Woodworking Forum)
From contributor K:
Is this a solid wood door? 11" wide stile? Opposite a 6" hinge stile on a 4' wide door seems like a lot of stress on the hinge side. I'm curious as to whether or not you could laminate engineered material into a large slab, veneer it, and rout out the lights. I have no experience with that approach, but the 4'x8' dimension had me thinking sheet goods as I was reading. A sketch and specs about the style would help.
From the original questioner:
I originally bid the job two ways; engineered stiles and rails with lvl cores and also as triple laminated solid wood. At that time the stiles were both 6" and the bottom rail was 8" and the architect said I could make it wider if need be. I just got the finalized drawing yesterday and I will try to attach it here. There is also a gate that will be fully exposed to the weather (So Cal) with the same specs but not as tall which worries me as well.
From contributor M:
That’s a tough call. I would prefer to see 5" rails and double the bottom rail width. However with a nice tight heavy mortise tenon type construction it might just fly. I have done a few pairs of doors that had no meeting center stile that we built up with three layers of engineered core and L shaped welded flat steel buried in the middle, veneered after. It worked well but it was a lot of work.
From the original questioner:
I normally use mortise with floating tenon joinery and was hoping to stay with that method. By floating I mean non integral tenons, loose tenons glued into a mortise in the rail and stile created by a horizontal slot mortiser.
From contributor D:
We've built plenty of 4' wide doors, and haven't had any problems. Mortise and tenon only. It is logically and emotionally the strongest. What I mean is, I've heard all kinds of arguments for dowels or loose tenons, pointing to this or that test done by FWW and others proving they are just as good. We've built thousands of doors and not one mortise and tenon joint has come apart. I trust my gut instincts as well. If you were hanging off a 4' long rail joined to a stile that was, just for kicks, say up on a thousand foot cliff in the wind, would you feel more secure with a mortise and tenon, or dowels/loose tenons?
For this particular door, you need to be engineering the rails as well as the stiles. In our experience, using a lighter core like Lightblock or even fingerjoint pine will reduce the weight, which is a good thing on wide doors. Imagine a gust of wind catching it and swinging it closed. The heavier it is, the harder it will be to stop. You'll need to verify your hardware is rated for the weight, and at least one screw in each hinge is 3" long. These screws are not included with the hinges. They need to be the same type of screw as the others, not a drywall screw.
From contributor D:
To the original questioner: I just reread your second post and see you're considering lvl as a core. I have to say I've had problems with it. It mostly occurred around hardware bores done by contractors who purchase our doors. The bare lvl core that was exposed soaked up moisture and expanded like crazy, cracking the face veneer right around the lockset. If you go with it I'd swab around the inside of your hardware mortises with a sealer.
From contributor O:
Contributor D is correct - mortise and tenon construction is best, and avoid the LVL. I favor integral tenons, not loose tenons, for simplicity and ease of construction. Integral tenons also give a good opportunity for cope and stick - increased glue surface. Make the tenons nice and long - 3-4" would be ideal, at 3/4" thick. 17" of solid wood (stiles) requires a larger expansion allowance than usual, and you may determine to make the stiles stable with solid core (like pine), crossbands, and thick veneer faces. I have gone to double tenons on 3" thick doors in larger widths and heights to increase the glue surface.
Whether single or double, square edge or coped, we also have never seen a mortise and tenon failure in 40 years of such construction.
As for rail widths, the wide bottom rail does not 'know' it is the bottom. Total cross section of the joints is what matters. Your drawing indicates a total of 36" of rail/stile interface - plenty for rigidity. The gate is also not at risk for racking.
From the original questioner:
I agree that integral tenons is a superior joint but I've used loose tenons many times before with no problems and will have to use this joinery due to budget constraints for this project. I am curious about your cores. Do you make them yourself or do you buy them? Do you know of a source in So Cal? My supplier only has the lvl’s.
What is Lightblock? I usually edge glue 3/4 to 1 inch laminations to the sides of the core then face glue 1/8" veneers to the front and back. I just got word that the owner doesn't like the design even though I thought it was approved months ago. They now want the glass to be approximately 4" tall making the rails substantially wider. This makes me more confident about the glue surface but worried about weight especially hinges. Can anyone recommend a good pivot hinge?
From contributor O:
Building large doors is more engineering and science than craftsmanship, although craftsmanship is still important. For sure engineered stiles and rails on this one. My big worry would be cupping or movement of the 11” wide stile. In our shop this would be either three layer, same species material depending on wood species and if it was quartered, rift, or a solid laminated stave core with a 4 to 7mm face veneer. The grain orientation of the core should be quartered or rift. Make sure the shrinkage ratio of the face veneer is similar to the core. A lot of shops have good luck with LVL cores but I do not care for them either. LVL does better with a thin face veneer because there is little movement in the LVL. LVL construction could have some advantages for the wide stiles. As I said a lot depends on wood species and exposure.
If we were building this door I would build Euro style at 68mm thick with rebated edges and Anuba type hinges. I see no problem at 2 1/4” thick with good butt hinge either. I would also not have a problem using dowel construction for this. We have good doweling equipment and dowels. At 2 1/4 thick a double row of 12mm dowels or at 2 5/8” (68 mm) a double row of 16 X 150 mm dowels. If doing tenoning a double tenon would be correct for 2 1/4” thickness. No matter what your joinery system the main thing for doors this size it has to be accurate. If your shaper or tenoner spindle is not perfect 90 degrees or tooling is off it is easy to build a warp or twist into a large door even if the material is flat and stabile.
We have built doors and windows with all systems over the years - true tenon, true through wedged tenon, loose tenon and dowels and never had joint failure. The failures have always been in other areas - finish, warping, splitting, leaking, and so on. The advantage of dowels or loose tenon is that it simplifies the construction process and tooling cost if you are producing a wide variety of frames and thickness. I do prefer double tenon construction for narrow window section corners though. I assume this door has IG. A door this size should be treated like a window and the IGU blocked so as to transfer the weight to the hinge stile.
From contributor D:
Lightblock is engineered European poplar, and weighs about 25 lbs. a cubic foot. There's six cubic feet of door there (48" x 96" x 2.25")/(12" x 12" x 12"), so roughly this door could weigh just over 150 pounds or double that if it was all oak. I'm impartial on hardware, having used all kinds and not having problems. I will say though I'm not fond of adjustable hinges. It’s a love/hate thing with most of our customers. A recent wide door we built was spec'd with Hoppe adjustable hinges, rated for doors up to 320 pounds. The convenience of positioning seems like a useless feature to me, adding more potential to get knocked out of whack.
From contributor K:
Bottom rail at 12" finished height and top rail at 8" finished height, the intermediate rails at the 6" finished width is fine. M and T construction is the way to go, not loose tenons. That way will most likely fail. Figure at least 3" depth for the tenons with lock pins that are 1 7/8" deep. Use Structura or a similar adhesive to hold this sucker together. My stock in trade is building large doors. Right now I'm doing a 93 1/2" x 42" Dutch door with two other matching OEM entry doors, all sapele. That reminds me, be sure to use a good species, 1/4 sawn. Not poplar if this door will see any kind of weather or heat/moisture changes.
From contributor O:
For pivot hinges I like Rajak. For less money Rixon is not bad either. Contributor D - I have not used the Hoppe adjustable hinges. Do they hold adjustment? We have had good luck with Zenit adjustable screw hinges on our euro doors. They are positive adjustment, but not something you would want the homeowner adjusting. We are building a entry now with SVB hand crafted 5x5 butts. They require hand fitting. At about $150 each we don't use a lot of them.
From the original questioner:
To contributor K: What type of adhesive is Structura? I did a Google search and didn't come up with anything.
From contributor D:
The Hoppe hinges actually are rated to 330lbs. The adjustments apparently are great if the door warps, allowing up to 1/8" up, down, in or out. I've actually had no callbacks, with several dozen out there over the years. There are different sets for RHI/LHO and LHI/RHO, with mortises into the slab almost 5/8" deep. You could consider it some extra insurance in case of warp. My negative impression I guess has no real basis other than the old hands in the shop who pre-hang and gripe about the extra complexity.
Finding the Lightblock source will take some digging, as we only bought some once several months ago, and I can't remember exactly when. Seems like I remember them being in VA, royal lumber maybe. Supposedly this is the go to core material in Europe. I actually thought it wasn't much if at all lighter than FJ pine, but it was clear and came in flat 4' x 8' sheets. Mostly we make our own core using our RF press - I was just experimenting.
From contributor O:
I look at the Lightblock core more for solid slab type doors. It could work for a stile/ rail door but probably overkill.
