P/S/P shoring idea

Hi everyone, new here, and though it's a bit presumptuous I had an idea the other day and thought this might be a good place to bounce it off people.

I've spent the past few months researching alternative building methods for a potential home project on a close friend's land, and for the past month have been more or less settled on the post/shoring/polyethylene method (possibly hybridized with some cobbing but that's another issue entirely).

The idea that struck me the other night, which I'm not sure is practical (hence the post) would be to use a biscuit joiner to connect the individual shoring planks. On the face of it it would seem to help strengthen the shoring wall, keeping an individual board from breaking. But I have two concerns that maybe more experienced builders might be able to address. First, would that actually strengthen the wall, or would the cut weaken it? I know the actual glue/biscuit are usually one of the strongest parts of the board when they dry, but that does not good if it weakens around where the hole was cut. Second, even if that isn't a problem, would this require boards to be thicker to cut the joints, potentially raising costs more than the corresponding gain in structural strength?

So I'd appreciate the opinions of people more experienced than myself.

Hy Garrett...Welcome to Permies.com....

I love fossorial architecture...because I love indigenous and vernacular architecture. Unfortunately, much of the "new age" builds have issues that stem from ignoring vernacular design principles and or not really understanding how "architectural systems" have to work in concert with each other. Some fossorial builds (wofati, earthship, walipini or Bikooh, etc) work better than others. It has been my experience the more they follow traditional formats the better they work...

...I'm not sure is practical (hence the post) would be to use a biscuit joiner to connect the individual shoring planks....

Well...no...a biscuit joint is not strong enough because the biscuit is not a very strong "spline" and relies too much on glue to work instead of the mechanics of the joint.

....However....I love the way you are thinking...it is actually beyond excellent and down right brilliant!...

Your mind is moving into "vernacular modalities." I see students with an aptitude for architecture often naturally thinking like an "historical builder." Your mind is taking the natural elements and subjecting them to a rudimentary solutions..."JOINERY." I am often reminding students...the most brilliant solution to a challenge are usually the most simple!

So, no the "cut" as you call it won't weaken the timbers, boards or plants. The "cut" is called a "mortise" and what the biscuit jointer is 'trying' to achieve is called a "splining." It doesn't do a very good job however. What is actually called for in this cast can be achieve in several ways.

1. An edge "lap joint"

2. A full length "splining."

3. Toggling or "free tenon" which is the strongest and can work in concert with number 1 and 2.

These 'toggles' can be mortised into the wood with just mallet and chisel (a lot of very fun work...lots of work) or if you do it professionally like I do we use several different types of "mortising machines."

I will give links to the two most common ones we use and some photos below...




Makita Chain Mortiser Model 7104L






Domino 700



Looks like a biscuit jointer but isn't...This cuts an actual mortise in the receiving member.