Create 25sqft Of Extra Storage By Building
These Box Stairs
By Andrew on November 19, 2013in Construction Details, Downsizing, Space Saving Ideas, Tiny Living
I know that many tiny houses today don’t have staircases in them because
people opt for ladders instead; however, I don’t think ladders are a great option for several reasons.
First and foremost, there’s nothing quite like having to climb down a ladder in the middle of the night
to use the bathroom. Further, as the home’s inhabitants get older, the use of a ladder will likely become
more and more difficult. The good news is that a staircase can work in the right size tiny home and the
space underneath it can provide for a lot of storage. Below I show you a step-by-step approach to
creating just such a space. In the example shown, the treads (what you step on) are 10″ deep and the
risers (the height of each step) are 8 7/8″ tall and the entire unit is built from 3/4″ cabinet grade plywood.
Learning how to calculate stairs is a lesson in and of itself, but I’ll give you a quick primer here to get
you started. We won’t be using stringers (the structural supports under most staircases which are cut
from 2×12 stock) as we want to maximize the storage capacity of the space. Thus the boxes.
1. Measure the height of the space requiring stairs. This is called the “rise.” Measure from floor
to floor and account for any finish flooring that may be installed later. This is especially
important if you plan to use floor coverings with different thicknesses on the main floor and the
loft. You will need to adjust the riser heights accordingly if this is the case so to keep the risers
consistent.
2. Measure the space you have in which to build the stairs. This is called the “run.” Measure from
a plumb line directly below the loft to as far away as you can go to provide a gentle rise for the
stairs.
3. Divide the run by 10″ as that is your target tread depth. If the number is even, then that is the
number of treads you will have. If it is not even (i.e. there are fractions or decimals left over),
then round up and that is the number of treads you will have. For example, a measurement of
8.67 would mean 9 treads would be needed.
4. Start over (sort of). Divide the run by the new number of treads. This will give you the exact
measurement for each tread.
5. Repeat the same process for the risers.
6. You can tweak the math any way you want here, but keep in mind that the closer you get to
code (minimum of 10″ treads and maximum of 8″ risers) the more comfortable your stairs will
be.
Now, let’s build some boxes…
Accuracy is very important when building stairs. In order to maintain a good flow, you must not have
a variation of more than 3/8″ in your risers. The more accurate you are in laying out the stairs, the
better.
Start with the big boxes. In this example, we have a large opening for a washer/dryer combo unit.
For any opening larger than 24″, double the 3/4″ plywood with glue and screws to provide adequate
support for the stairs.
Mark the locations for the 3/4″ x 1″ strips of plywood used as nailers. Be sure to anchor all edges of
the treads and risers either with nailers or by screwing through existing boxes.
Apply a high strength, structural adhesive to the back of the nailers and secure with 1 1/4″ screws
every 4″ – 6″. Again, make sure that everything is perfectly plumb or level.
Apply the same structural adhesive to the nailers in preparation for attaching the risers and treads.
Build one box at a time, starting with the risers. Attach to the nailers with 1 1/4″ screws every 4″-6″
over the adhesive applied in the last step.
Make sure the treads are installed level and attach with glue and screws as before. As a side note,
the 2×4 in front of the step was used as a nailer because the spacing for the last tread was only 1
1/2″ due to the height of the wheel well (which the stairs hide, by the way).
Add the smaller boxes, one by one, to complete the stairs.
I did not add a standard riser and tread for the last section where the stairs meet the loft. Instead, I
created a “double-wide” tread and “double-tall” riser. This makes it easier and safer to get in and out
of the loft. Notice that the larger opening has the double thick plywood I mentioned earlier to
increase the strength of the box as it spans the larger opening (roughly 31″ to provide room for the
washer/dryer combo).
Once all of the stairs are in place, cover the edges of the boxes with what is called a “face frame.” This
is typically made of a finish grade wood. I plan to install mine once the stairs are covered with their
own finish material. The treads will have the same flooring as the rest of the house and the risers will
have a decorative wood finish. After the face frame is installed, I will create custom doors to cover the
entire staircase and complete the look of the unit.