Making a framed ledge and brace door
This article describes one way of making a fairly traditional framed ledge and braced door. This type of door construction is ideal for large heavy doors such as garage or barn doors, and can also be adapted for some designs of gate. While not an entry level carpentry job, it is one well within most peoples reach if taken carefully.
Pressure treated softwood is a reasonable choice for many applications. Three different sizes will be required; A full thickness timber for the top rail and both stiles. A wider and thinner stock for the lower rails and braces, and then finally some suitable planking to provide the door cover (traditionally T&G or "matching" is used here).
Ideally the thicker stock used for the stiles and top rail should be the same thickness as the thinner stock used for the lower rails plus the thickness of the planking combined.
For the process described here a router is required, however the remainder can be done with basic hand tools if required. A chisel morticing machine will make the job much quicker, and a chop saw or sliding mitre saw will make cutting all the stock square quick and easy.
Preparing the materials
Start by cutting both rails to the full height of the door. Then cut the top rail, and the two lower rails to the full width of the door (do not cut them shorter to fit between the stiles, since you will need the extra length for the full depth tenons). Make sure the rails are cut square, as this will have an effect on the flatness of the finished door.
Carefully mark out the tenon positions on the rails. Then cut them as follows:
(note cutting tenons is not described here in detail, but whatever method you want can be used; e.g. hand cut with a tenon saw, on a table saw with tenon jig, using a sliding mitre saw with trench cutting capability, with a dado blade, with a router and jig etc).
Top Rail The top rail is made from the same stock as the stiles. The tenon will need to be positioned in the mid point (front to back) of the stock. Since this will go right at the top of the frame, and we don't want the ends of the stile to split, it is usual to make this tenon less than the maximum height - typically leaving an inch or so if wood at the top of the stile over the matching mortice. An improvement is to in addition put a haunch on this tenon to maximise the strength of the tenon without risk of weakening the stile too much.
If using a haunched tenon, then remember when chopping the matching mortice to nut cut the full depth on the haunched section.
For added strength when assembled a couple of saw cuts down each tenon will allow wedges to be made and driven into the joints later.
Lower rails The lower rails are made from a wider and thinner stock. This allows space for the planking to sail past them while still remaining within the profile of the door. As a result the tenons on the ends of these rails will be cut flush (or close) to one side. So as not to weaken the stile too much by having a long morticed section, a central haunch can be included in these tenons to retain some extra strength in the stile. Again saw cuts can be included for wedges later.
Stiles Next mark out the mortice positions on these, and chop them out. A powered chisel morticing machine is ideal here, however carefully drilling most of the waste with a lip.n.spur or forstner bit and squaring up with a chisel is also acceptable. Routing may be tricky due to the depth of mortice required on larger doors.
Braces Cut these long enough for purpose, but don't cut to shape yet.
Dry fit and test assembly first. If all looks good then glue up the rails and stiles and assemble. Use sash cramps to pull everything tight. Check the frame for square. You can tweak this while the glue is wet by lifting and dropping the door on one corner as required. If you find it difficult to get it to "stay" where you want it, then slacken off the cramps, and apply them at a angle across the frame - this will have the effect of pulling it in the direction you want. If you assemble the door flat on the ground, then you can also add some weights to make sure it stays flat.
Once you are happy it is square and flat, mark and cut the braces to fit. The braces should rise up from the hinge side to the free side of the door. These can be glued and screwed into position.
Finally glue up wedges and hammer them firmly into the slots in the ends of the mortices. Leave the wedge ends sticking out until the glue has set and then cut them off flush.
Cutting the rebate
For the planks to lay evenly on the door you now need to cut a rebate with a router into the inside edge of the top rail and both stiles. This is on the outside of the door. The rebate depth should be down to the level of the thinner stock used for the lower rails and braces. The width is less critical, but half and inch of so is usually adequate.
You will need to tidy up the two corners on the top rail to remove the radius of the cutter and leave them square.
Cut all your planks to length - so they run from the top of the rebate in the top rail to level with the bottom of the stiles. Check the fit width ways. If the door is not an exact multiple of planks wide, then trim the side of both the edge panels to match. If using T&G, then test fit all the boards before fixing. Don't fit the boards too tightly together since you want to allow for some movement due to humidity changes. Fix the planks with nails in the middle of each board into each of the rails and the braces. This should allow the wood to "move" and the tongue of each board will simply move in or out of its groove without opening up a visible gap.