M&T or Half Lap?

[ByronBlack]

I'm going to be making a start on the doors/lid of the greenhouse project on the weekend and i'm working out whats best to use for the joinery. The rails and stiles of the doors/lids are 25mm x 47mm (2x1).

I'm thinking that the stock might be a bit too thin for a strong M&T as I will only get an 8mm wide Mortise in the stock (if I follow the one third rule).

Whereas if I do a half-lap i'll get more glue-surface, but there'll be no mechanical strength to the joint as the glue will be doing all the work. Could this be pegged with a dowel for added strength?

So, what is the opinion on the most suitable joint bearing in mind it's outside in the sun/rain etc all day everday. (i'm using the waterproof titebond glue for the joints).

 

[wizer]

what about half lap with a screw covered by a plug?

 

[Keith Smith]

I'd use bridle joints, much easier than a M&Ts but still have a good degree of mechanical strength and a big glue area.

I made a green house a few years ago, it has been hammered by the weather but the joints are still holding up. I used polyurethane glue by the way.

 

[Wanlock Dod]

Byron,

As a mortice and tenon has less exposed parts, as well as some inherent mechanical strength, it may hold up better outdoors than the easier options.

Cheers,

Dod

 

[caretaker]

I have gone for a M & T with a long screw as well.
I am now on the doors to the lean-to, that is.
Its the painting that's taking the time.

 

[Max Power]

Go with the mortice and tenon, a half lap bears no comparison in terms of suitability for this project

 

[curlywol]

8mm is fine for a M&T joint. With polyurethane glue there is no need for mechanical fixings.
John

 

[ByronBlack]

HI fella's, thanks for all the feedback. I think i'll go for the M&T as the only worry I had was with the 8mm being too thin, but seeing as a number of you say it'll be fine, I can go ahead with that.

One last thing - considering the external conditions, would it be wise to use a stopped tenon rather than a through tenon so no end-grain is showing?

 

[caretaker]

Hi,
I have used a stopped tennon and used a router for all the M T's, cleaned up with a chisel, good luck.
Just go for it.

 

[ByronBlack]

Cheers everyone.

I'm quite happy to do the M&T's as i've done them on all the frame sections so far and my two jigs that I made makes these a doddle, better get on with it then I guess