Strongest tenons on gates

[Mister S]

Evening All

I'm just at the planning stage for a new set of gates for the side of the house. One will need to be 1m wide and one 2m wide. They need to be about 2m tall, so the larger gate will be almost 2m square, which is pretty big so will need strong joints (as well as 3 rails, braces etc).

I've read up on drawboring and wedged through tenons and read some posts that say you can use both for maximum strength.

My question is, if you have say 2 holes for drawboring in a tenon and 2 more at the bottom of the kerfs for the wedges, does having 4 holes quite near the root of the tenon weaken the tenon at all? I will be using softwood.

Actually a second question - I can't find anywhere that says the best way to glue the wedges in. Just at the pointy end of the wedge, or all along its sides in the kerf.

I haven't tackled a project this big before!

Thanks
Steve

 

[RobinBHM]

Make the through tenons at least 15mm too long, it makes wedging easier.

Make the saw cut quite wide for the wedges 3mm or so.

I always angle the ends of the mortice so it is wider on the outside, tapering the mortice about 3mm beyond the marking out. Wedges about 12mm wide. Glue the whole of the wedge before banging in.

Gates need timber with a higher moisture content than standard kiln dried timber -I would condition the timber outside before starting.

 

[Mister S]

Thanks for the quick reply Robin

Good tips for the wedging.
I hadn't thought about moisture content, but the timber is in the garage and the gates will actually be under a carport so not exposed to rain. Hopefully there won't be too much movement after fitting.

Do you think 4 holes would weaken a tenon too much?

Steve

 

[RobinBHM]

I think I would not drill any holes at the bottom of the wedge saw cut. 1 draw dowel is enough for a 100mm tenon, 2 for a 200mm or so tenon. Decent shoulders improve strength. Also to help prevent dropping the braces can be housed into the rails somewhat.

 

[Mister S]

Robin

I hadn't realised 1 draw dowel would be ok for a 100mm tenon (which is about what mine will be). I think I've seen a post elsewhere that suggested a stress relief hole at the base of the kerf cut isn't necessary in softwood (Steve Maskery?) but I wasn't sure.

Thanks for the help
Steve

 

[Bradshaw Joinery]

if they are painted use plywood, or tricoya (preferably) and groove it to look like tongue and groove. it will never drop then, and you wont need such a hefty frame...

 

[Mister S]

Hi Olly

I know what you mean but I'm pretty much tied to T&G or at least rebated 4x1 made to look like T&G as they have to match other nearby doors.

Steve

 

[RobinBHM]

A t and g door 2m x 2m will have a significant wind load, l hope it is in a sheltered location or restrained by an electric opening arm.

 

[Mister S]

The overall size is a bit of a concern - total area is 3m x2m. The gates are under a carport, house to one side, fence to the other and set back about 2m from the opening so fairly sheltered, but a wind hitting it directly head on will have an effect. Hopefully it won't be more than rattling!

I've never had a problem with the carport roof or fence.