Whilst we have a vast range of double doors, we can also show you how to make to doors into a pair and have given you three categories where we show what we can provide, the obvious bit, check all avenues to make sure a standard pair of doors isn't available as this is the cheapest option, the not so obvious bit is that it took longer to write this than it will take you to do the job.
1. Double check all your overall sizes, not the individual size of one-half of the door pair.
2. Rebates are the lipped edges that allow doors to "overlap" where they meet and remain flush when closed, rebates are normally 12mm deep and half the thickness of the door edge.
3. Choose two doors of the nearest size but remember, adding a rebated edge to both doors will add 12mm overall, machining the rebate out of two doors reduces the overall size by 12mm.
4. Adding the edge is the easiest, choose nice, clean and straight timber of a type to match the door timber, if the doors are 35mm thick, the timber should be 17mm x 12mm thick, if 40mm thick the timber should be 20mm x 12mm and if 44mm thick the timber should be 22mm x 12mm.
5. Cut the chosen timber to match the exact height of the door.
6. Choose which way you want the "leading" or 1st door to open and make sure you place a little pencil mark on the door edge where you wish to place the additional rebate.
7. Lay the chosen rebate timber flat, add a little squiggle of glue along its length, stand the door on edge and place the rebate timber on the chosen door edge in the chosen position, take pins/small nails of about 30mm, tap them through the rebate timber but do so in such a way that they are angled through the rebate timber away from the door face to prevent expensive accidents, you really do not want the pins coming through the door face.
8. Take a nail punch and tap the pins slightly below the surface, now fill the pin holes with a matching timber filler and sand this while still soft, it's easier and gives a better finish than leaving it to go hard before sanding.
9. Repeat all of the above from processes 5 - 8 on the 2nd door leaf that will form the pair, you now have a pair of doors.