any ideas on where this peg hole should be placed? by measurements, where i would like to put it (red X on the timber, 3" in) would have it in a check that goes in 2" at the end and a fair way up the tree- i get the sense this may split wider if a drawbored peg goes through it.


how close to the edge of the timber do you imagine the peg-hole could be placed? this is eastern yellow cedar that was standing dead when harvested- so it's dry and willing to split. or do i just ease up on the drawboring and live with the fit? this will be a beam supporting an outdoor amphitheatre. building in the direction of up, so there will be weight on top of this. i wonder if the peg could go in after assembly and time, letting the weight settle on the joint???

i assume it is in a mortise?
where is the heart of the timber in relation to the check?
is it housed?
how deep the housing?
how long the tenon?
how thick?

thanks for such quick thoughtfulness- yes, it's through a 2X6 mortise, 6" deep.

the check goes in radially straight towards the heart, which is sound and centered in the timber.

i wasn't intending to house the joint. there's not quite enough room- the beam is 8" wide and the posts 7", the thought being, with a little roof of flashing on the beam, that the rain doesn't drip down the works.

you mention that this is a tie beam - so a post comes into the mortise that you are trying to peg?
does the peg in the photo point up the post?
or the beam sits atop the post?


drilling the tenon after it is assembled is certainly a safe(r) way to do this, eliminating the 'pull' from the drawbore. (or not pegging it at all, depending on the answers to the above questions)

in the end i think it is a judgment call based on how you lay out that mortise, where the heart lies, and how much check you think will run into the cheek of the mortise.

howdy fellas,

all i can say is that you should look at your peg you are about to drive. turn the grain square to the force...

by the way, Toivo, those are some big wood chips you have laying on your floor. tell us about how you make the chips fly.

Hi Toivo,

Have you considered offsetting your tenon towards the lower face. I am assuming that the lower face is not cracked since the upper face is affected by a drying radial heart check. Drive a tapered peg from the underside so that the peg hole is not completely filled with peg on the upper face. This should help reduce the probably of the peg propagating the crack any further.

Occasionally one will come across situations where pegs need to be driven from inside a building towards the outside for example when a space in a row of houses in a town is being infilled preventing the pegs being driven outside in.

Regards

Ken Hume

Toivo, could you explain the purpose of the post? This will shed light on the purpose of the peg and its needs.

Tim

thanks so much for your kind responses. Tim- to answer your question: the beam will sit on two short posts, that will in turn be scribe fit to 2 big boulders. together they will bear the front of a deck. a timber pergola will sit on top of it, though joined into the deck's framing.

that's an interesting, straightforward strategy Ken- as i understand, to peg from the other side, which is solid. then that solid cheek of the mortise would pull the post into place. hmmm...

i'm really wondering whether a peg is necessary. there will be a lot of weight bearing down on this. a peg might just hold up the settling and hold the joint open. i don't forsee any problems with raising it sans pegs. thoughts on this possibility?

Mo- the chips on the floor are from hewing the posts- you can see one to the right of the beam in the picture. i used a finish and then a swedish broad axe then a drawknife for this. the mess is also from putting a curve on the braces with the adze- a little tough with the dry cedar, but a pleasant smelling mess in any case!

Unless I'm mistaken:

There are peg to edge of timber standards.

There are peg to end of tenon standards.

These standards help to insure that the relish on the end of the tenon doesn't blow out, and the edge of the post to split as well.

All of these standards help to figure out where to place the peg hole in an ideal situation. But if you have some special considerations like the crack shown in the picture above, your placement may have to vary.

When pegging a through tenon the peg hole is usually 1 1/2" off the shoulder of the tenon so that you can meet the end of tenon standard rule. If the mortise is housed in the post this places the peg hole in 2" off the edge (if housed 1/2").

Sometimes the peg is centered on the tenon, unless it is a very wide tenon as a wide tenon may shrink and lift the tenon up off the bottom of the mortise, and put all the beam's weight on the peg. So in this case the peg should/could be lower so that when the tenon shrinks the gap would be at the top.

I'm not totally sure where you can get a copy of the peg hole spacing standards. But I'm sure someone here can post a link to them.

good to know the standards- i had just centered the pegs in the mortises and tenons as it looked as if that much behind the peg in the tenon and that much 'in front' of the peg in the cheek of the mortise would hold. in this case, with this tree, the tenons from the heart of the posts are definitely of tougher wood than the edges of the beam.

so the peg hole ideally ought to be 1 1/2 inches in from the shoulder of the tenon? i'm assuming that's to the edge of the peg hole, so 2' to the center? that might work. again though, would there be a pressing need for pegs in this application- m&t joint between a 10' 10X8 load bearing beam (weight of a 10X12 deck and a timber pergola, plus dancers) and 3' 10X7 supporting posts?