Let's get it on!
Step 1: Our problem.
Step 2: Our solution.
We choose to use more plywood, two big wood beams and a little bit of steel.
We make the math for the hight of the steps and found the correct angle to have the 2.17m that we have to climb.
Step 3: The angle
Down here in Mexico we make everything in centimeters so I gonna use centimeters and a aproximate in inches, in the end its the same.
We calculate 10 steps to climb 217 cms (85 3/4 in) and thats a little bit shorter than the average height in construction... but you gonna need to add steps and take a few fractions of inches in the case you have a higher floor.
We use a 3 parts to 4 parts scale to calculate the angle... this means that if we have 15 cm (6 in) of step and a 20 cm (7 7/8 in) height... the distance from the horizontal edge to the most higher point in vertical are 25 cms (9 14/16 in). You dont need to make hard (in my personal case I dont remember how to do it) mathematical operations to get this numbers... only draw it on a 100% scale on a big paper and its done.
So if you measure that angle... thats the one who gonna make all the work from now on.
Step 4: The steps. Materials.
First of all we need to desing the step shape. We decided to go with a 60 cm (24") long x 30cm (12") width. So its a very easy desing something like a "P" shape. (you will see it on the images).
All the secret of the space saving miracle of this kind of stair its on that "P" Shape and the position of it, you dont gonna put one next to other, you gonna put one OVER the other, and 'cause the widht is only of 6" in reality instead of the full 12" step you see on the regular stairs, so we are saving at least the half of the original long of the stair.
For make the steps we choose a 3/4" pine plywood... and making the calculate we know that we only gonna use a half of the board, but we were not too sure about the strenght, so we decided to glue two of them to make a bigger and stronger panel. You have to cut the board in half and then glue one half to the other to obtain a stronger 1 1/2" board.
Use any wood glue you know... and make sure that all the surface is on contact with the other. you can even put a few screws where you think may need it to keep it together.
Step 5: Cutting the steps.
Then we draw it over the board... but we make two stencils one for the right and one for the left... so we can alternate them and minimize the waste of material by puting one "inside" of the other.
We use a jig saw to make the cuts... dont forget to calibrate the angle of the blade and be patient 'cause some times the blade make a non desirable angled cut insted of a clean 90 degrees angle. Take it easy and practice... you can also draw the steps whit a 3/8" space between one and the next...this gonna be very usefull in case you need to rectify some cuts. (So dont be afraid to make a mistake...we can always find a solution)
Step 6: Finishing.
We want this stair on duty for ever!!!
Step 7: The side supports
In this case we use a 10' beam and 2" thick.
We have to draw a scheme for this to make sure we are in the right direction.
First you need to se where you wanna put your stair... we use a very easy and secure way to attach this beams to the floor and to our second floor. (see the image). We use the first beam of the second floor to lay our stair... and we only put 4 guides to make it go straight, not for support part of the weight.
In the down part we put two strong steel parts to support the weight and this two parts goes attached to the floor by two big 1/2" screws. This is this enough to keep the stair in the floor.
Step 8: Attaching the steps to the sides.
We use two different sizes... 5" and 7 1/2" one for the 6" side and the other for the 12" side.
The 7 1/2" part has 3 (3/16") holes for screws in one side and 2 in the other. The other one, has just two holes in both sides.
this two simple parts are one of the most important parts of our proyect, 'cause they gonna support our weight.
Dont forget paint the angles... to avoid the rust.