• We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Haunched or not?

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

stuartpaul

Established Member
Joined
11 Feb 2003
Messages
1,052
Reaction score
43
Location
Somerset
I'm about to start on a set of panelled garage doors and I've been trying to work out wether I need to use haunched M&T's or not? I wasn't going to considering 'plain' ones acceptable strength wise.

Basically 100 x 50 stiles with 150 x 50 rails. Looking to use 70 mm deep tenons.

If haunched are best why?
 

deserter

Established Member
Joined
5 Nov 2009
Messages
551
Reaction score
0
Location
Shrewsbury, Shropshire
You'll have to haunch the outside tennons, other wise you'll end up with bridle joints. Also a point worth mentioning is that on a 150mm rail your going to want a double tennon, so basically you'll have tennon, haunch, tennon, haunch on each joint.
 

andy king

Established Member
Joined
17 Aug 2007
Messages
413
Reaction score
0
Location
Pill, North Somerset
deserter":1lzrlzuo said:
You'll have to haunch the outside tennons, other wise you'll end up with bridle joints.
No, you can still make the tenon narrower to allow it a proper M&T, but a haunch is definitely the way to go.
The haunch is designed to keep the rails from twisting or moving, locking the full width of the rail into the stile.
One other advantage usually overlooked, is water integrity.
If there's any breakdown in the shoulderline, without a haunch water will wick through - the haunch prevents it. (depending on your construction - a rebate will still give integrity, but if its a grooved one for panels then there's the chance it can still let water through)
As pointed out by deserter, wider tenons will need to be made as doubles - middle rails are usually tenon, haunch, tenon, bottom rails are tenon, haunch, tenon, haunch.

HTH,
Andy
 

Sawyer

Established Member
Joined
7 May 2011
Messages
581
Reaction score
2
Location
France
Haunches also give you a much stronger glue line. Otherwise, the un-haunched part is just end grain glued to side grain, which has very little strenght, no matter how good the glue is. For something like a garage door, you want to build all the strength you can get into your joints. I'd also through mortice and wedge them - stronger still.
 

Jacob

Pint of bass, porkpie, and packet of crisps please
Joined
7 Jul 2010
Messages
19,009
Reaction score
1,052
Location
Derbyshire
Haunches also stop what is sometimes called "lipping" - where the faces of the rail and stile go out of flush for whatever reason.
The haunch needs only to be as deep as the tenon is thick i.e. square in plan, unless there is a slot, rebate or other detail to take account of.
 
Top