Phase One: Flooring/Foundation - COMPLETE!

Phase one is complete!

We have been separating this project into phases in order to set these short term goals and not be overwhelmed by the big picture. Phase one encompassed the trailer prep and flooring. A little detailed information about the materials required for this part of the project.

Trailer Prep:

We purchased a 2006 trailer off Craigslist for $2,100. It is in excellent condition but we decided to be extra diligent and replace all the decking on the flat bed. This required us to remove the screws that were securing that decking to the steel cross beams. However, many of these screws were stripped (happy day!). So we took a grinder and cut those screws off. In turn, this meant we needed to drill many new holes into the cross beams when it came time for us to attach the new boards.

 Ripping up the original decking boards

We purchased six 2 x 8 x 20' fir boards, which we stained for weather protection. After staining all six boards, we realized that the boards were actually 16' instead of the 20' that we had ordered. I called up our building supply guy (shout-out to Dirk at Franklin Building Supply!) who promptly apologized and offered to send us over the 20 footers at no charge. And we got to keep the 16 footers, too! SUPER HAPPY DAY!

Staining the new decking

Let me just say that it is a great idea to do some price comparisons before choosing a building supply place. We originally purchased the 2x4s for the floor framing from Home Depot because it was convenient at the time. But our local building supplier actually has way better prices than HD (about $1 cheaper per board). We now use Franklin Building Supply for all of our wood (plus other various supplies, like house wrap), Idaho Lumber for odds and ends (hardware, etc), and Construction Material Thrift for all re-purposed appliances and doors/windows.

Before screwing those boards onto the trailer, we decided to take it one step further and power brush all the surface rust off the beams, then repaint the whole trailer with rust-oleum paint. After that whole process, we finally were able to screw the decking boards on, which involved drilling a pilot hole and then self-tapping screws through the boards and beams. We placed the boards 7" apart so that the 2x8s were evenly spaced apart across the 80" wide trailer.

Trailer Decking

We plan on replacing the tires as well, which the seller mentioned to us before purchasing the trailer. All together, we will spend $3,000 on the trailer, which includes the costs of all the "upgrading", the new tires, and the hitch package we bought for Jon's car. Not bad! Trailers can go from $4,000-$6,000 for the size and GVH requirements that we had (10,000 lbs), so we figure we saved at least $1,000 with some good old fashioned elbow grease.

Flooring Prep:

Next, we went ahead and put the three sections of floor framing together (Jon did it all himself one day while I was at work. Took him only a few hours). Since we are extending the flooring to be a tad wider than the edges of the trailer, we had to frame around the wheel wells. Hence, three sections of framing. All together, the floor framing is 8' wide (the bed of the trailer is only 7' wide).

We then purchased some steel brackets/joists that we nailed at each intersection of 2x4s in the framing. These are about 42 cents per bracket and we bought about 40 of them. A relatively cheap purchase for some extra strength and support.

Then we took the styrofoam board insulation that we purchased and cut it so that they fit into each section of the floor framing.

Styrofoam insulation cut to fit

Installation:

House wrap goes on first over the decking boards - secured with nails. 

Floor framing goes on after! Framing attaches to the decking with brackets and lag screws.

With the trailer and the flooring prepped, we nailed some house wrap over the trailer decking in order to place a weather-proof barrier between the outside and the insulation. We have seen other tiny house builders do this in order to prevent water from splashing up underneath the trainer, through the decking boards, and into the insulation.

After the house wrap was nailed on, we placed the floor framing on top. Keeping it in place with a couple clamps, we nailed on a few more brackets/joists where the framing met the decking boards for an initial loose attachment, plus extra security in the long-run. It will be SUPER DUPER strengthened once we drill the lag bolts up through the bottom of the trailer and through the framing. But that doesn't have to be done immediately.

Next we placed the pre-cut insulation boards into their appropriate slots, followed by spray foam around the edges to make sure we filled in any cracks and achieved a tight seal.

 Jon securing on some more brackets

Spray foam that we used

Spray foaming the edges

FINALLY, we placed two 4x8 OSB plywood boards onto the framing, creating our flooring! OSB is the cheapest kind of plywood you can get, and is actually stronger than the expensive plywood that people tend to buy for siding their homes (Bat & Board, i.e.). The reason for this, is that instead of the OSB being solid wood, it also has a very strong glue mixed into the wood particles that make it up. It is uglier than regular plywood, which is why people don't use it when it is visible from the outside. The OSB will eventually be covered up when we install our flooring on top of it.

BOOM! FLOORING! DONESKI.

Now onto Phase 2, which is the exterior walls...stay tuned, people!

Kind of a bad picture of the finished product. But in conclusion, we have a floor!