SUBS #5:
Trial System Extensions

So far I have discussed the residential or lorise grade of panels and connectors because it is the most commonly useful.  However, the Simple Universal Building System will need other grades.

This article develops a tentative component matrix to roughly outline four grades of panels and connectors for the SUBS.  Other grades can be developed for non-wood panels, special purposes, or extreme applications.

Further calculation will produce a more efficient use of material by fine tuning all parts of each grade to be more equally sturdy than this proposal makes them.  My guess is that critical engineering will reduce the thickness of these connectors and bolts to be more equal in strength to the panels they support.   I've used regular 1/8" increments over the typical range of available thicknesses for the steel connectors.  Other increments are also commonly available.   There may actually be no need for anything as massive as 1/2" thick connectors, as thinner ones may be more than adequate.

One of the elegant aspects of this system is that you can change specs on the fly, and all it means is you pull parts from a different bin.  If you only need 3/16" thick rings for a particular purpose, you don't have to use 1/4".  Universal geometry allows you to change your mind about how strong something needs to be without altering your building geometry.  Unless you must jump between 6" and 12" thick panels, the volumes are all unchanged by redesigning the building to be stronger or weaker.

Careful engineering and testing of these various applications should produce a few simple rules of thumb that enable you to easily and accurately design a sound building in your mind.  ["Hirise goes up X floors, with Y floors of lorise on top." Etc.]

Load and span tables for 6" square tubing posts and beams in various thicknesses would be very helpful for exotic designs.  They must exist somewhere, but I haven't found them.

On the other hand, if you get TOO fancy and "efficient" with your engineering and design too many grades, multiplied parts inventories and having the wrong parts in stock would cost a lot.  SUBS uses such simple basic industrial components that you pay relatively little for having things stronger than they "need" to be.  Inventory inefficiency and mistakes can quickly gobble up engineering savings and still be ravenously hungry.

In the meantime, the basic lorise grade is VASTLY stronger than the typical house, so you don't have to do much engineering for a residence [unless you want to design it DOWN so it's not so overbuilt].  You basically just design rooms to suit your needs.

Here is my current best effort to lay out ranges of components vaguely matched to each other.  The general concept and range of the matrix is more important than individual values [which will evolve with more exact engineering] because it shows possible extensions of the universal geometry.  The available standard sizes of things are often more important than how strong they "actually" need to be.  I guess the system would eventually fail under increasing stress by the steel bolts and washers rupturing the framing members.  I would be surprised if the steel itself failed.

I don't know how many floors up you can go with any grade.  Lorise grade is plenty strong for most residences.  It's way overbuilt for a two and probably even three story building.

It will take calculation and testing to fully develop the system:
Shove one line of the matrix left . . .
another right . . .
move a column up or down . . .
fine tune a few increments . . . .
and you have the "SAME" system . . .
but even BETTER!

Here is my first gross approximation for system wide values.

Crunch some numbers and post your own conclusions!

COLUMN HEADINGS:

HOLE & BOLT SIZE is the size of the bolts that join components, and therefore of the holes in those components.

PLYWOOD THICKNESS is the plywood skin of the panel.

CONECTOR AND POST GAUGE is the thickness of the connector rings and posts/beams.

# STUDS PER PANEL is the number of studs running the long direction of the panel.

MAX CLEAR PANEL SPAN is the longest span that would be generally used in that grade for roof and floor panels.

NOTES ON GRADES:

FENCE GRADE:
Only good for fencing.  No horizontal surfaces.  No roofs or floors.   1/8" thick 6" square tubing posts are probably way overbuilt for a fence, but it's the normal minimum thickness.  Fence grade would have two bolts at each panel end.

LORISE GRADE: [Residential]
Suitable for houses and lorise apartment or commercial buildings.  Roofing panels over 12' long have joined plywood, not one piece.  Lorise would typically have two bolts [and connectors] at each panel end.

HIRISE GRADE: [Commercial]
Suitable for taller multi-story buildings such as apartments, hotels, offices, etc.   Roofing panels over 12' long have joined plywood not one piece.  Hirise panels would have three bolts and connectors at each end.

INDUSTRIAL GRADE:
One foot or thicker panels.  Suitable for very long spans and extremely heavy loads.   Past 12' long you can't have truly one piece decks because you must join multiple pieces of plywood in one panel.  Hoever, the much deeper joists permit enormously strong panels.  Industrial panels could have three or more bolts and connectors at each end.

Industrial panels could be built in a number of configurations depending on span and load.  They could be built with only the two outside studs on a 4' wide panel skinned with 1-1/8" plywood to meet code for light duty flooring.  Or they could be framed up with 3, 4 or even 5 joists for heavy loads and long spans.  Lumber commonly comes in 26' maximum lengths, but other materials could be used for longer spans.

A foot thick industrial wall can bear two floor panels on top, splitting the width in two 6" design units, so various parts can mate in many different ways.  You don't have to hang floor panels from connectors with bolts, you can also set them on top of walls [and bolt them to connectors on the same walls if you like].

MIX AND MATCH

Different grades could mix and match in the same building for different purposes.  In a hirise apartment, the wall panels and connectors of the upper floors could be lorise grade, because they only support a few floors.  The walls and connectors of the lower stories would be hirise grade, since more floors rest on them.  Essentially, you'd have a lorise building bolted to the roof of a hirise building.

On the other hand, the floor panels of the lower levels [not the connectors] could probably be lorise grade, since there is no extra load on a floor from those above it.  Conversely, a warehouse with heavily loaded floors would have hirise floor panels on all levels.

An entire hirise apartment building might in turn sit on an industrial grade commercial structure with huge spans, high ceilings, parking garages, and drive through corridors for delivery trucks.

The modular universal geometry, rather than imprisoning you in a few boring designs, frees you to imagine limitless variations that can be simply engineered by choosing from a menu of basic components.

Bill Dur <billdur@net-prophet.net>

modular.systems * Simple Universal Building System * "Superior By Design"