Is that a hat on my house?

Here’s a little update on the BentoBox progress thus far. The winter months are starting to fade away as the Seattle weather changes. A lot of prepwork inside has led us to where we are: 2×3 studs are attached to the container walls as the structure for the insulation and siding, the window framing is in place and I am ready to cut holes for the kitchen and bathroom windows. We’ve had several comfortable days of sun and temperatures in the 60s F (15-20 C). That’s roof weather!



My house now has a little hipster hat. Yes, this will be the basis of a roof deck covering about an 8×8 area over the kitchen and bath. The design detail called for some extra head scratching to be sure. It’s important for me to ensure the house width stays under the DOT standard of 8′-6″ (2590 mm). This gave me an opportunity to create a shadow line and a way to still have a continuous soffit vent. For those of you inclined, I’ve attached the detail below.



The deck joists at 12″ on center sit on perimeter rim joists. Simpson Strong-Tie products are used extensively. These include: A24 steel angles (which measure 2″ x 4″) and stainless steel bolts, washers and nuts (to prevent reaction with the container’s weathering steel) hold the rim joists to the container, and H1 hurricane clips and joist hangers are used above to ensure everything is stable, and will not uplift in the event of a strong wind (which is what will happen anytime the house is moved on the freeway).


The tight spacing of the joists meant it was very challenging to get a framing hammer in there for much of the work. A palm impact nailer, suggested by Ryan Mitchell of The Tiny Life did the job nicely. I had no idea it would be so different from a typical nail gun.


You load each nail individually, which allows using the proper nails recommended for the fastener system. Magnets and ball bearings hold ferrous metal nails in place so you can line up the nail with your work. It pounds the nail in with successive hammering action, versus a single quick burst of air. It’s a bit like the game “Operation”. Don’t touch the sides, and don’t touch the nail to anything you do not wish to drive it into. It’s very sensitive. ALWAYS wear your safety goggles.


Attaching hurricane clips. Hannah Crabtree of makes quick work of this with the new palm nailer.


I’ve purchased a very simple plastic trench drain – intended to be used on a driveway outside a garage opening. This comes in a 10 foot length. I do not plan to cut it until I’ve finished the tapered deck that will send all water to this. This is sloping at 1/2″ per foot and the built-up roof deck will slope at 1/4″ per foot toward the middle. A roof membrane will be laid on top. My next update will show how I am insulating, venting and flashing the roof to keep everything dry and cozy below.