Hi Will & Don,

I think that an idea might be emerging that is worth pursuing and a cross pond design comparison would be an interesting undertaking.

Re common purlin versus Common Rafter

I would surmise that this might have much to do with snow load and I also understand that (Northern) New England can be subject to hurricane force winds that can and does flatten forests.

All of the above and in particular the standard width of a frame might have some significant effect on the roof pitch.

A standard house frame in SE England is one pole wide (16' 6") and I would hazard a guess that a typical standard New England frame like a cape or the like would be much wider. With a steep roof pitch this would push up the ridge height exposing the frame to quite a bit more wind load.

We would need a frame cross section with timber sizes and species. Joint details are not really required at this stage.

Re 3D Models

Producing a Sketchup 3D model is fairly simple. Sketchup will import perfectly from heavyweight CAD programmes such as AutoCAD allowing non CAD users to view and manipulate a model with relative ease.

The demonstration of FEA that is interactive is a bit more problematic and I need to think about how this could be achieved when a recipient is not equipped with the same analysis programmes. I have prepared this kind of thing before for windmills i.e. how they perform in different wind speed and directions but this was done on the basis of preparing a whole series of outputs for a series of fixed inputs and then animating same in a screen show so that variable inputs / outputs could be demonstrated.

It would be nice to hear from the rest of the regular contributors and also some of the TFEC members who do not seem to regularly frequent these haunts.

A digi pic of the two contender buildings chosen to square up in this cross pond match would usefull.

How would we judge the winner ?

Regards

ken Hume