Liam O’Brien

PV & Electrical Design Engineer

Engineering a µHouse

A blog following my progress designing and fabricating a modern ~200sqft tiny home

Trailer and Flooring Woes

Getting the subfloor on the trailer has proved to be somewhat of a fussy and infuriating experience. After first finding out that two 4×8′ plywood underlay sheets place side by side with one edge square to the trailer facia board (exactly as called for in Tumbleweeds plans, see photo) would not actually reach over to the other side (leaving a sizable ~3in gap). I then discovered that when the board was extended 1 1/2in over on the trailer ends (again to meet the facia) the opposite edge just missed the metal L-beam joist, this meant more cutting, fussing, and cussing; always a good combo.Facia-Overhang

While I would like to blame the fabricators (AMP Trailers of Florida) I have to say that more than likely the engineer who designed the trailer didn’t accommodate for that 1 1/2in extension when you attach the facia boards, in my experience welders are sharp guys and know how to follow a plan, but that all goes straight out the window if what they are working from isn’t worth the paper it’s printed on.

I also speak from the knowledge that vanishingly few “Professional Engineers™” are any good at making actual things in the real world. The required skill set for graduating from one of these “accredited” engineering colleges usually track something like this: thermodynamics? check, calculus? check, fluid dynamics?, sorta-kinda check, about 20 other super complex subjects that they will most likely never use in 99.5% of any real world situations? check and check. 

What all this wonderful education misses out on (to say nothing of hands-on shop experience) are skills like: high school math/arithmetic (how many ft^2 of plywood do we need?), dimensional tolerances (will it fit? and how tightly) basic physics (energy in = energy out*), communication, writing, and documentation skills (you will have to talk to non-engineers, get over it), budgeting and finance (can we actually pay for any of this?). If only half of graduating engineers had these skills down pat the world over would be a better place and presumably my trailer would have been designed correctly too, but alas nothing is ever quite the way you expect. Remember kids, never trust another persons drawings or specs, only what you can measure or test. Case in point, a 2×4 is not actually 2.00″ by 4.00″ it is roughly 1.5×3.5in, again plus or minus a significant margin due to variations between saw mills and thermal expansion. The moral, always check yourself, no matter how large or established the company or it’s engineers.

Now back to the skill saw…

* It really is Energy In x Efficiency = Energy out, since nothing is ever perfect and never will be, but we can simplify in this case.


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