The Foundation, Part 3

Finished most of the floor envelope (adding the last layer underneath will have to wait until the plumbing, electrical and framing bolting are complete) and started the wall framing.

1. Completed lower insulation (This will add an additional 7.5R value to the floor, bringing the subtotal R value to R28 ; the additional 3 Inch layer added later will bring the total to R38)


2. Installed 3/4 inch plywood (birch on one side), drilled bolt holes through to steel frame (for tension ties to wall framing) and rubbed in water based varnish.*


3. Prepped, flashed deck area and pieces.


* Note: All 2×4’s, 2×6’s and 2×8’s are SFI Certified Wood.

The Foundation, Part 2

The envelope of my 144SF tiny house required a lot of research. As many tiny house builders and enthusiasts know, such a small structure has unique issues with moisture, energy, heat retention, airflow, cooling and design.

A word about why I chose the aluminum flashing vapor barrier vs. a radiant barrier with bubble wrap. When I grew up in Minnesota, we had lake homes and cabins where “critters” had eaten through all kinds of softer material like cardboard, bubble wrap, tin foil, thin masonite and 1/4″ plywood, among other things.

Although I love wildlife, I am concerned that could easily happen under my sub-flooring with all those “critters”  visiting me when I start touring the US and so  I chose a variety of R value solutions.

I want to make sure the Silver Bullet envelope is as watertight (yet breathable), as durable, recyclable and repurposable as possible. That means that some of my choices will be different than others.

After speaking with several manufacturers I chose the EcoFoil single layer perforated barrier.  It is more time consuming to install than just wrapping your floor framing; however, it will allow me to sleep more soundly knowing my sub-flooring is secure and more energy efficient.

1. I continued with the remaining bracing of the subfloor framing.


2. Blocked out plumbing, and installed Owens Corning for structural rigidity.

Subfloor2f3. Installed Bonded Logic Blue Jean insulation for additional R value


4. Installed EcoFoil radiant barrier per their specialist, David Arnold.


EcoFoil’s article about the Silver Bullet

Note: This was a busy week as I am preparing my reclamation show artwork whenever it rains (which was 5 days this week) and so Saturday was the only dry day for building outside.

The Foundation

This week finished with:

1. Putting down an aluminum vapor barrier over the five reinstalled 2×8’s. I overlapped the layers 5′ inches and secured them with XtraBond®150 – Premium Grade Silicone Sealant and then taped the edges with aluminum tape.

2. I have framed the sub-flooring with 2×4’s secured with premium galvanized screws. I anchored the corners with Simpson L-braces and also used those to secure the framing to the trailer 2×8’s.

3. The side 2×8 bottom’s were flashed with aluminum and bolted to the trailer bed (2 in front, 6 along each side). The sub-flooring was bolted to the trailer sides.

(Thank heavens our Seabrook Home Depot Manager, Brandon Hardy, suggested I get an Impact Drill. It saved my hands from getting numb. I counted them; 382 Simpson screws, 126 wood screws and 12 1/2 inch bolts were required and I haven’t even gotten to the 3/4 inch plywood flooring yet!)