Door repair, end to end joints

[Nad]

Hi,

I need to repair some extremely large top hung, sliding workshop doors, bottom of both stiles and a section of the bottom rail has rotted out. My question is what would be the preferred method on the end to end joints? Would you ever use a mortise and tenon in this situation or is it best to stick with a splice or lap joint? Timber is approx 8x2.

Many thanks

Nad

 

[RossJarvis]

Hi,

I need to repair some extremely large top hung, sliding workshop doors, bottom of both stiles and a section of the bottom rail has rotted out. My question is what would be the preferred method on the end to end joints? Would you ever use a mortise and tenon in this situation or is it best to stick with a splice or lap joint? Timber is approx 8x2.

Many thanks

Nad

I think the lap would be best, maybe a spliced lap joint. E.g. at least one of the cut sides having an angled cut rather than both being square across. I can't quite see what benefit an M&T would be in this instance, particularly as I would think it would make a lot of work.

 

[ED65]

A scarf joint is one of the best fixes here assuming you can form one accurately. Back when they were more commonly used halving joints were also known but they chose not to use them which probably tells us something.

 

[kevinlightfoot]

I would also go with an angled lap joint ,scarf joints are very difficult to cut using hand tools .Be sure to use a good preservative treatment such as Cuprinol 5 star or Johnstones do their own equivalent which in my opinion is just as good

 

[Nad]

Many thanks for all the input. Will probably go with some type of lap joint then as I should be able to prepare the door side with a router, can't really get it onto any equipment to do the scarf, its nearly 10ft tall!

 

[RobinBHM]

If the stile has really gone bad at the end, it is possible to cut a long angled cut to form a scarf joint and glue and screw on a new length of stile. The cut may need to be over 600mm long, which is a long gluing area and easy to cut with a skil saw or track saw.

Ive done such a joint occasionally to make up a very long section of timber and it is a very strong joint.

 

[MusicMan]

Agree with the above. The problem with a standard lap joint, or a mortise and tenon for that matter, is that only half the thickness of timber contributes to the strength of the joint, as the other half is glueing onto end grain. If it is scarfed or an angled lap of say 45 degrees or less, then the other half of the joint starts to add its strength, and with a long scarf there is no weakness at all at the joint. As long as the glued surfaces are both flat!

Keith