How To Install Folding Attic Stairs
A note from NH... Thanks to
STIRA Folding Attic
Stairs for allowing us to reprint this article on installing attic
We have made some slight editing and formatting changes for better
readability and added a few notes of our own.
Regardless of the brand of folding stairs you
choose, the installation procedure will be very
similar. However, specifics such as the size of the "rough opening"
or fastening locations may vary. Always refer to the manufacturer's directions
for your stairs.
After reading this article, you will know for sure whether
this a project you would like to tackle!
Before you install your attic stairs...
Though installing your own folding attic stairs may seem daunting, don't worry...
it's not as a big job as it may seem at first glance. Unlike many "DIY" products, you need not worry about
assembly, we've taken care of that at the factory. All you need do is
cut or enlarge the opening and fit the stairs. Stira Folding Attic
Stairs are designed to be a completely integrated unit ready for fitting.
the Stira Folding Attic Stairs should take no more than two hours
(though significant framing changes in the ceiling may add hours to
Here are a few things you
should bear in mind before you start.
1. Check the attic for constraints to enlarging the opening,
such as pipes, wires etc.
Bear in mind that the Stira Folding Attic Stairs will arc about 14" (35cm) beyond the
opening as it folds and unfolds. (NH: Measure carefully...
this may cause clearance problems if installed in closets or small
If the opening is in a bathroom, consider a new opening in the hall or
Make sure you order the correct Stira Folding Attic Stairs size to suit your ceiling height.
Place an old sheet on the floor to protect your carpet or wooden floor.
6. If your attic contains trusses instead of
by" joists, be careful!! The consequences of cutting
trusses can be severe loss of roof strength or other possibly dangerous
structural issues. If you are unsure how trusses work, don't do
any cutting before consulting a builder or building inspector.
- Utility knife
- Bevel square
- Measuring tape
Enlarging the existing opening...
The first thing to do is strip away the existing trim.
When you remove the old trapdoor you will see that
there is a small lath around the opening on which the trapdoor sits.
This should be removed so what you are left with is bare rafter.
Now you need to mark out the length of the opening.
You can do this with a pencil. Just mark the length of the
opening onto the plasterboard.
Important! The Stira Folding Attic Stairs will arc about 14" beyond the end of the opening as it is
unfolding, so you should keep this in mind when locating the stairs.
Measure the frame of the Stira Folding Attic Stairs and
cut the opening 1/2" (12mm) longer.
You can cut the actual plasterboard one of two ways. The old fashioned way is to use a utility knife to
start the cut on the underside of the ceiling, once you have the cut
started you can use an ordinary carpenter's or drywall saw. If you have a Jigsaw
this makes the matter easier but definitely dustier!
Once the plasterboard is cut away to the desired size you can now cut the rafter.
Depending on how the rafters are running you may need to use a
bridging piece to create the rectangular opening needed to fit the Stira
Folding Attic Stairs. Make the opening as square as possible to
help in proper fitting later.
Once the opening is complete we can move to the actual fitting.
Installing the Stira Folding Attic Stairs
The best way to actually fit the Stira Folding Attic Stairs is to lower it into the opening from
above. At this stage you can fit the door handle before you raise the
Stira Folding Attic Stairs into the attic.
Once you have the stairs in the attic, you need to screw two pieces of lumber
to the underside of the ceiling at either end of the opening. Any piece
of waste lumber will do, you could use the old trim you removed
It's important that the boards do not extend more that 1/2" into the opening.
This is so the frame will rest on the laths in it's approximately final
position, but the trapdoor will be free to open to test it's function prior to
Once the temporary
laths are in place you can lower the Stira Folding Attic Stairs into the opening.
Securing the frame
Make sure the stair frame is square by measuring across it, corner to
opposite corner. Using a carpenter's square is unreliable because the
sides of the frame (where the stair springs attach) may be slightly
bowed till they are secured with screws.
Do not install the stairs too tightly within the opening!!
THIS IS IMPORTANT!!
If you cannot move the stair frame into a square position, you may have made the
rough opening a little too tight. You may need to enlarge the opening slightly to allow the outer frame to
move that little bit. For example, if the inner frame is hitting the outer frame on
the left hand corner then you need to move the outer frame forward on
the left hand side.
The simplest way to do this is to drive a small wedge between the frame and the joist on the
left hand side at the hinge end of the frame.
(Notice that the Stira has very heavy frame construction. Many
other brands use much lighter "1x" wood, so using a wedge is NOT recommended.
You may permanently damage the frame.)
Secure the frame to the joists
with 3" or 3 1/2" screws at the locations indicated in the instructions.
Once the frame is secured you can remove the temporary laths and fit the
trim. It's best to start at the front end of the opening with the
trapdoor closed. Leave about 1/4" gap between the trim and
the actual trapdoor all around to prevent binding.
Cutting to length
Cutting to length is crucial to the proper sitting of the stairs on the floor.
Its important to bear in mind that you should check both sides of the stairs, don't assume that the floor is level. Open the Stira Folding
Attic Stairs and unfold it and fold the bottom section back out of the way and rest it on the floor.
(See graphic below left)
Now using a straight piece of timber, place it on the face of one of the side stringers of
the stairs and extend it to the floor maintaining the angle of the stairs. Mark the piece of timber where it intersects the stairs at the
You should check the other stringer separately, as the measurement may not be the same. You can now transfer
this measurement onto the bottom section and mark the cut line.
Now saw off the
excess and sand the ends. Just double check that you have the angle
marked the right way around, in other words the angle of cut
will be the same as the angle of the step.
Problem. After I've made the cut to the two side stringers and there is
a large gap between the top and middle section of the stairs when I
climb the stairs (graphic above right).
If you notice a gap
between the top and middle sections of the stairs this means the bottom
stringer has been cut to the wrong length. You will need to recheck your
measurements, as you may need to take a little more off the bottom
section. But you should check the operating
instructions first to make sure you are using the Stira Folding Attic
Congratulations! You should now have a
fully-fitted Stira Folding Attic Stairs!
again to STIRA Folding Attic
Stairs for allowing us to reprint this article on installing attic