Hello Francis,

Originally Posted by Francis
I have not decided on layout method yet most books have square rule focus...I was thinking of using an offset method of line layout from what is called the Reference Edge Rule which I assume is what you refer to as "Modern edge rule".
Again, I would stress, if following a given Author and their text, unless you have extensive experience in timber framing, to not deviate from what they are employing for layout in their text. Mixing and matching layout systems without intimate familiarity can lead down some “rabbit holes,” that may not serve a first time project well...

Originally Posted by Francis
...This "Modern Edge Rule" is what is taught in the majority of the books I have so I am loathed to stray from it in my first build...
And I don’t believe you should…The text you are reading and learning from currently, and planning a project around, should be the format to follow. If you select one that employs a line rule system, if that interest you, then you may be better served as the system is broader and much more flexible in context, and history...

Originally Posted by Francis
...If you have a good book you can recommend for asian line rule centre line rule I would be interested...
Publication wise, if possibly considering actual line rule layout, there are a few good ones out there in English. I have written and/or photo documented on different forums and blogs also some basic steps and your free to contact me directly should you choose...

The following are currently the best examples out there that illustrate “Line Rule,” modalities. There are many more going back over 1000 years in other languages of course:

Master's Guide to Timber Framing” by James Mithcell

Link to a great review by: Jake Jacob’s...

Master’s Guide to Log Building” by James Mithcell

If you think you will ever work in the round or in live edge materials, this is a must have publication as well…

The Complete Japanese Joinery,” by Hideo Sato

This is a wonderfully illustrated book that covers traditional templating and line layout modalities. However it is wickedly written and a very poorly edited book. I have been in contact with this publisher for decades over the typos, mislablings and confusion found within the details of this book. The book originally was actually two construction manuals from Japan (of course written in Japanese) and they themselves the amalgamation of about 10 plus other books and illustrated manuals with similar examples found in Korea.

Originally Posted by Francis
...This method, though not centre lined/asian line/soul line rule stops being edge rule and once again becomes "line rule" layout...
“Snap Line Square Rule,” the common vernacular now in contemporary reinterpretation of “line rule.” This started in the late 70's here in North American timber framing with its dominant progenitors being Jack Sabon, Will Beemer (Heartwood School), et al. from their publications, classes and related venue.

To be very clear, the actual (et: traditional) “Edge Rule Layout,” (or “Rule Layout” as another historic term for the same modality) had nothing to do...at all...with any snapped lines of any kind anywhere on a log or timber…

“Edge Rule” systems of layout, as it was traditionally taught and performed, has only existed for about 350 to 250 years with the historical origins most certainly coming out of mass production of large timber Mills, Barnes and related heavy timbered architecture of the early colonial periods here in North America transitioning for the more labor intensive, cumbersome and bespoke “Scribe Rule” modalites of timber framing. Edge Rule employes, as its key elements, a large framing square, dividers very often, levels, story poles and related board reference tools. A length of string was often part of this arsenal, as was a plumbob, yet no snapping of lines. There are strong indications of Edge Rule perhaps also being employed by production Shipwrights as a modality for mass producing timber structure of a uniform context out of...nonuniform timbers...for the mass production of certain ship elements.

My context to this understanding was taught from the perspective of a group of Old Order Amish Barnwrights ranging in birth dates between 1877 and 1898. Within this appreciation it was made clear the distinction between scribe, edge and line layout methods of layout. This and over 4 decades of continued passion for understanding historic layout systems in woodworking, has led me to a keen perspective of their application and very distinct characteristics in use and application. Thus, I tend not to follow reinterpretation of these systems, as they work well as they had been developed over centuries or millenia (depending on type) and rather lean toward the original contextual definitions.

I should also be clear that they are not always in the center of a timber or log, and there may well be more than one line within reference context as well, especially on rafters, or heavily curved livedege timbers as just two examples which may have multiple reference line elements that work more within a plane of context than just the “soul line” alone...

Originally Posted by Francis
...As for altering plans the only thing I really need to look at for my plans is roof overhangs or lack of them to be more precise I need them for the hot and wet climate I live in....
That is very understandable, as many designs are sorely lacking in proper roof overhangs so that modification is more than justified in my opinion. I typically never have less than a two foot (600mm) eave overhang on a structure, and larger is not uncommon…

Uplift, shear and related wind loads with these larger roof overhangs can be arduous to deal with but not insurmountable at all. This is where a PE with actual timber framing experience is a valued member of a project team. Even for small projects they are worth what they have to charge for their efforts. I would also offer, from my experience, to never hesitate “pushing back” on their solutions. I have a very personal and long lived relationship with the PE I work with, and seldom (never actually...LOL) accepting or liking the first solutions to a given challenge they may foresee. Because of this the project is always made better by this push and pull between what the “engineering” states needs to happen in a frame and what the final solution ends up being. PE, when good, makes you a better Timberwright, and I certainly give those I have worked with for over 30 years a lion's share of influence on projects I have been fortunate enough to be part of...