How much wane is acceptable?

[danreed76]

Since I am cutting all of our timbers for our frame, I am trying to make the best use of every tree.  I have seen many frames with waney (natural) edges on the corners or even whole sides of timbers having a natural edge.  We like the look of this, as well the fact that it allows more options for what timbers can be obtained from which logs.  Question is, how much wane is acceptable without a reduction in strength of the timber?  It seems to me that we can tolerate quite a bit, as the frame was originally sized for white pine and we are using yellow (longleaf and loblolly) pine,  but have maintained the same timber sizing.  This would be mostly on braces, rafters and joists, where I can make good use of some of the smaller trees that have to come down anyhow.

[Jeff]

I have no idea but I'm interested in the answer. My theory though would be as long as the wane did not detract from the joint, that it doesn't matter.

[Brad_bb]

Yeah, I can't quantify, but I can say that you'd want to use the ones with wane as posts (in compression), and less so for horizontal members.

[Jim_Rogers]

The problem with wane, sometimes, is that you need a good edge (arris) to pull your dimensions from.

If you can arrange your timbers, posts or rafters, so that a good edge is on the reference side, they it can work out to use your timbers with wane.

However there would be some deduction from full size for something that does have a lot of wane if an engineer looked at it. He may use a "log" value instead of a "timber" value in his calculations.

In the case sited above, where a stronger wood is being used, then this may not be an issue.

At the recent weekend workshop we had a tie beam that had a lot of bark still on the side of the beam.



So we rolled it over so that we got a good arris for the reference edge and a good edge for laying out the brace pockets and their housings.

The client wanted the waney side towards the door so that it would be seen when entering, but this didn't work out to be.

Taking a draw knife to the bark and removing it is usually standard practice as the bark on most types of wood will fall off and make a mess when it does.
Also, the bark on a cut timber sitting in a pile waiting to have joints cut in it, will draw bugs. I usually draw knife off the bark soon after it is milled.

However in this photo, it was done after the joints were cut:



Jim Rogers

[Dave Shepard]

The amount of allowable wane is determined by the grade of timber the architect or engineer specified. The white pine I use is graded by NELMA rules, and as we are operating on a native lumber stamp, all of this lumber must be considered No.2. If my timbers are of a higher quality than No.2, then I must get a grader to come in and grade the timbers for them to be used as a No.1 or Select Structural, etc. I think wane allowances are pretty lenient on No.2. What grading system is in place where you are? I think most grading rules can be found online.

[danreed76]

In speaking with the local inspector, he has stated that since we are not using standard stud construction, he is not nearly as worried about grading, as the engineer's approval of the timber we are using.  I guess as far as grading rules are concerned, around here it would default to the southern pine council, but I will look into it further.


As always, thanks for all the feedback.  To this point, I have been able to look at each timber coming off the mill and orient the waney edges based on the reference edge as well as how it will appear inside the house.  Most of the time, I have been fortunate enough to get a good timber, sacrificing only 1/2" to 3/4" of wane.  Other times I have set the timbers in a seperate pile for potential downsizing if they are determined to be unsuitable due to the waney edge. (still a few others have found themselves relegated to the world of two-by-whatevers because they just refused to conform).

If I ever remember to get the camera out of the truck, I'll start asking my questions with pictures attached, like a real FF Timber Framer.

[ljmathias]

I think Jim started down this path but didn't go as far as I would: measuring and cutting needs square edges.  As Jim said, you need one good face and edge to measure and lay out.  When I did the single bent for inside my daughter's house, I used or picked timbers that would have waney edges for the "natural" look.  Turned out great, too, and I'll get pictures when we finish the interior.  Discovered that during mortising, I couldn't clamp and couldn't measure or transfer lines easily around the beams- round corners are a real pain then.  This led to a slight misalignment in one of the joints but we'll live with it as it wasn't too bad.  You might also think farther down the road to how you'll finish the frame inside and out- do you need flat surfaces and edges?  Will wall coverings intersect at odd angles?

Anyway, you're doing exactly what I would do, both to use more of your resources and to get a unique and beautiful character and "look" to your finished product- good luck.

Lj