Before it looked like this, it looked like this:
We had found these 21 skids made up of 4-1/2 foot wide pine planks nailed to 8 foot long 2×4’s, for $100 on Kijiji. Each skid gave us four, eight-foot 2×4’s, and with these we built virtually all of our stick frame structure. The roof was made later of partly salvaged, partly new, 2×6’s; the sub floor was made with new pressure-treated wood to withstand for as long as possible, but the framing of the walls was done for $100 with wood that we were told would be incinerated after its one-time use as a skid to ship something or other. We are also going to use the pine planks for our flooring later on. I believe this guy still gets more of these skids all the time, in case anyone in southern Ontario is interested.
With a lot of email and over-the-phone help from our friend Benn who we met in Portland back in April while he was building his tiny house Kangablue, we decided exactly how we would have our trailer built for it to best suit us.
In late June 2014 we made our single biggest purchase through Long Haul Trailer Sales out of Atwood, Ontario, near Listowell, and bought our new custom built trailer. We shopped this one around, and Steven at Long Haul Trailer Sales gave us the best deal, and we’re happy with the trailer.
This is an 8’x20′ straight flat bed trailer. It has twin 5,000 lb. axles, and itself weighs about 2,300 lbs. dry. We had 2″ cross beams welded across the chassis every 16″ to mimic how our 2×4 sub floor frame would be constructed. Later the sub floor frame would be dropped on top of the steel cross beams, and would be lag screwed from the bottom up, to suck the wood down tight to the cross beams. These cross beams are welded beneath the 3-1/2″ wide steel chassis, so that when the 2×4 sub floor frame is dropped into chassis frame, it will rest flush with the top of the metal (2×4’s actually being only 3-1/2″ wide). In this way we have gained that extra few inches in eventual interior height, as we are restricted by a 13.5′ maximum height for road travel. The deck of the trailer goes over the wheels as opposed to between them, so in this way we have maximized our floor width while keeping within the allowable width of 8.5′. The trailer also came fully wired for brakes and lights.
So when you rip apart all of those skids (which will take dozens of hours and wear out your arms for a little bit), you can rebuild them onto the flat bed so that it all looks a little something like this:
I want to go through how we attached the sub floor frame, and eventually the wall framing as well, to the metal of the trailer bed, as we had found there to be less than ample information available, and for an aspect of this build which could be considered more crucial than many others, in that it will prevent your house from flying away while you tow it down the highway later on.
Metal Supermarkets in Kitchener delivered to us a few sheets of thin gauge mild steel (I think it was 20GA but can’t remember). The mild steel was more expensive than aluminum or galvanized, but if coated somehow, would last longer for us. It was also much cheaper than something like stainless steel, which would not need to be coated, but is very expensive.
On the interior side of the steel sheet, we painted it with TremClad, to prevent rusting. On the exterior, we smeared this rubberizing paint to prevent rusting and also add a tiny bit of insulation and additional underbelly protection. This second part was a less than glorious task using products that must be evil in some sense of the word, and if we were to do it again, we would find less toxic ways of protecting our sub floor.
So we dropped the sheets into the trailer bed…
and then dropped the 2×4 pressure-treated sub floor onto the sheets. We obtained a dozen or more donated cans of spray foam insulation, so we spray foamed the overlapping parts of metal and around the perimeter as well.
Before dropping everything in, however, we had marked and drilled vertical pilot holes, about 40 0f them, through the cross beams of the trailer.
This way, later on I could crawl under the trailer and drive about 40, 6″ long, 1/4″ wide lag screws, from the bottom up, through the metal cross beam and into the wooden sub floor, sucking it down tight to the frame.
We had also drilled horizontal pilot holes through the frame of the steel chassis, five per side, so ten in total, where we later hammered 8″ long, 1/2″ wide lag bolts through both wood and metal, connecting them horizontally as well.
Eventually when the walls were framed and in place, our friend Marco came by with a bigger and better drill and drilled a final set of holes, a dozen of them evenly spread around the perimeter, through the kick plate of the wall frame, through the sub floor, and through the metal of the trailer frame, and hammered and secured bolts here too. I believe these were 12″ long and 1/2″ wide.
I’m going to discuss hurricane straps and coil strapping another time, but as far as securing both the stick frame and the sub floor frame to the trailer bed, this is how we went about it.