I rented a truck and drove down to San Bernardino where I picked up the trailer that I ordered from Tiny House Basics (A company called New Trend Custom Trailer actually fabs the trailer). It’s 28’x10’ wide, with 3x 7k axles for a total of 21k GVWR, electric brakes on all axles, squared off fenders, and a custom bumpout on the front where I plan to put utility stuff.
Getting the trailer back to SF took 11 hours - combined with the 55 mph limit for towing, I had to pull an oversized permit (CalTrans took 3 days to process it, delaying my departure from San Bernardino) and take a non-standard route. The 10 foot wide trailer took up most of the lane - making staying centered extremely nerve wracking. At some points I had to just commit to taking up two lanes, especially in construction zones.
First order of business was underlayment. We used 3/4” Advantech X-factor underlayment, which is tongue-and-groove and has a nice “crust” on the OSB that mostly just puddles water instead of soaking it up. We had to pre-drill the trailer and countersink the holes before screwing in #12 metal to wood screws, as the trailer would strip if you tried to pull the head of the screw into the underlayment with torque alone. Screws were roughly 16” on center to intersect with the frame members. I bought 210 screws and we used every single one of them to attach a total of 9 full 4’x8’ sheets (More full size panels were used as the last “row” of half-width panels all needed to have a tongue on them). Before screwing we prepped the trailer surface with Acetone and laid a fairly thick bead of Loctite PL400 subfloor adhesive (claims to bond to metal and coated metal). Julian and Tapan were onsite and we were able to finish the entire deck in one day.
