We have had many inquiries about the dimensions and construction of our ‘AWARD WINNING‘ tiny house storage stairs so this post will cover those two topics in detail. We have also just released a FREE ‘storage stair construction document’ that can be DOWNLOADED HERE which provides further details about the construction of our stairs and pairs perfectly with this blog post.
The process is a bit complex, and like anything, it and the materials could be tweaked to better fit your style. It is worth noting that we knew the design of our stairs early on in the process of building our tiny house and installed blocking in the wall and floor prior to installing the sub-floor and interior paneling so there is adequate support beneath and a sturdy location to anchor the stairs to in the wall.
The stairs are designed with 1’-0” x 1’-0” treads and risers except for the bottom stair (which is angled to provide a little more surface area for sitting and to match the entry angle) and the top stair (which is larger to facilitate easier entry into the loft and is where any left over inches in height are located).
We wanted a plywood edge profile that was thicker than ¾” but thinner than 1 ½” to keep weight down but to look (and be) robust. Because we only had ½” and ¾” thick plywood readily available we decided to laminate two sheets of ½” plywood to create a 1” thick stair edge profile for this project. We started with two sheets of ½” birch plywood and cut the treads and risers slightly larger than their finished size and laminated them together using wood glue and all of the clamps we had.
We then measured and cut the individual 1” thick pieces to their finished size, including the necessary 45 degree corners to create the matched edge grain miters. Cutting the angled bottom stair miter really tests ones ability to work with compound angles. Once it was time to start gluing the treads to the risers, I was introduced to the Festool domino joiner which is a tool that replaces my previous experience with a biscuit joiner. The domino joiner uses a special drill bit that spins and oscillates side to side to carve a unique hole that looks similar to an oval. these holes are precisely located on both sides of your miter joint and then the domino, which is this systems replacement for the biscuit, is glued and inserted into the hole with its other end doing the same on the corresponding miter before the pieces are pushed tight and clamped to complete the joint. The benefits of the domino over the biscuit are a stronger joint and a higher level of precision because as long as you are accurate with your hole placement, the joint simply aligns itself perfectly once the dominos are inserted where as there is more slip tolerance when constructing a joint with biscuits.
Once we had all five of the leading corner miters constructed we cut out a notch in the toe of the stair to allow for the addition of a steel flat bar inlay to protect the toe kick corners from the inevitable abuse they will have to endure. The flat bar is affixed to the plywood using ¾” long square drive, stainless steel screws that sit flush thanks to a matching countersink drilled into the surface.
Now that all of the prerequisite work has been done to the individual pieces, it is time to start to build the stairs by joining each step, one at a time. We added one stair per day because we only had enough clamps for one at a time and wanted to give the joint adequate time to cure before taking the clamps off and adding another one. We followed the same process as before, installing five dominos before gluing and clamping each miter joint.
Once the stair was a single zig-zagging line of plywood our friend used his trailer to transport it from the shop to our tiny house build site, making sure to cover it in a tarp and saran wrap to keep all water and road debris from damaging the unfinished plywood.
The stairs arrived unscathed and looked great when dry fit in place. During construction we left the top riser longer than needed so that we could test fit the stairs in place and draw a line at the exact height it needed to be cut. Pro-tip. When cross cutting plywood, especially expensive birch plywood with a thin face veneer, score your cut line with a razor blade to prevent the inevitable chipping and flaking that can occur.
The next step was to truly install the stairs in place using d.i.y. brackets made out of 1” x 1” steel angle to anchor the stairs to the pre-planned and already installed blocking in our wall cavity. The structure to be built underneath the stairs would require two more 4’x8′ sheets of 1/2″ birch plywood and would serve three functions: To support the stairs, to divide the space into cubbies/shelves and to be a sturdy substrate to eventually mount the cabinet doors to. For this supporting structure we once again chose two pieces of ½” birch plywood laminated together. This allowed us to create the perfect two tier support in which ½ of the plywood butted against the underside of the lower stair heal and the other ½ continues to butt against the underside of the toe of the higher stair, creating a direct bearing condition in both instances and much surface area to glue and screw the plywood to the back of stair riser.
We set the edge of these supports back from the front edge of the stairs by two inches to ensure that the cabinet and door hardware would be recessed rather than stick out further than the plywood stairs. This was to ensure that the clean plywood edge condition of the stairs becomes the main focus and so that there was not a chance of snagging clothes on the door hardware when walking by.
The bottom of each support was anchored to the floor and horizontal shelves were added using the same d.i.y. steel angle brackets as before. We also painted a strip of wood and applied it to the front edge of each vertical support as this area would be seen in between the cabinet doors and we wanted it to match the walls.
Because of the unique sizes we needed for our under stair storage doors it was clear we would not be able to just order them so we choose to make them out of ½” MDF (medium Density Fiberboard) for a few reasons, including:
- We wanted to make the front surface of our storage doors plane with the front face of the 1/2 plywood wall that hides our pantry.
- We were getting tired of dealing with thin face veneered birch plywood and the amount of prep and caution involved in handling and processing it in order to produce a nice corner and edge condition.
- We wanted single piece, simple looking doors (which that is harder than it sounds when trying to prevent the natural shrinking and swelling of wood that causes flat planes to warp and bend).
- Because MDF has a consistent makeup throughout the section of the material and is not affected by things like directional wood grain, it doesn’t have a natural tendency to curve and this makes for a more uniform painted appearance
- I had once built a sub-woofer box out of MDF (in an attempt to make my 1996 Ford Taurus bubble seem even the slightest bit more cool to my friends in high school) and was surprised at how well the MDF held up in less than ideal circumstances (the trunk of said ford Taurus).
We got the 4’x8’ sheet of ½” MDF off the shelf at home depot and had them cut it in three strips that were a touch larger than our finished door sizes so that we could fit it into my tiny Honda Civic. At home , we then cut all of the doors to their finished dimensions and installed them to make sure everything fit. This step will be A LOT more frustrating if your cabinet frames and stairs are not perfectly square; ours are not perfectly square. In our defense they are not WONKY, but they are not square and therefore each door has very subtle variations and angled edges to fit in with our intended reveal between each door. We decided to use a partial reveal cabinet hinge that allowed for us to hone in on the exact reveal wanted above, below and in-between the doors.
Initially we started putting a thin coat of spackle on the edges of each door because the edge of MDF “drinks up” moisture much easier than the face, much like plywood. This step was a pain and after doing a few test pieces with and without the spackle decided to skip that step and we then took all of the doors off and began priming them with an OIL based primer which was recommended by the ‘experts’ on the google. A coat of white paint followed and they were ready for the tedious installation process. The last touch was installing the same IKEA “blanket handle” hardware that are used on all of our kitchen cabinets.
After almost 18 months of use we ave found the 22″ width, 12″x 12″ treads and larger top ‘landing tread’ very functional and easy to use on a daily basis and would not change the dimensions if we did it again. We hope this helps anyone looking for more information on our stairs!