Flats come in various forms and sizes. A flat is a fake wall. If you look around you, you will see walls that are solid, usually made out of wood or plaster, and go from floor to ceiling. Some walls have holes in them. A door is a hole in the wall. So is a window. How to build a flat. Let me start at the beginning. What is a flat? It’s a fake wall. It can be any size you wish. Look at a wall in the room you are in now. What size is it? Most likely it’s between 8 and 10 feet tall and maybe 8 to 16 feet wide. Well, your flat could be this size or bigger. Here’s the catch. Once you’ve built this huge flat, will it fit through the door? Most flats are built in one of two different styles. Hard and Soft. Hard flats are covered with a thin plywood and soft flats are covered with cloth. We’ll talk about the actual materials later. The cloth flats are much lighter and easier to handle, however, they appear a bit less like hard walls then plywood covered flats. The hard flats tend to act like real walls. If you have a small theater and the audience sits close to the set, hard is the way to go.

First we need to draw a plan.


Hard covered theatrical flat. Much like the soft flat in it’s framing, this flat offers a more sturdy wall surface. If actors are going to be brushing upon the walls


Soft covered theatrical flat. This flat is framed flat and covered with muslin. The framing is usually 1″x3″ pine laid flat and the joints are held together with key stones and corner blocks. The muslin is glued, stapled and then sized. This photo shows the methods of building a flat, however, you’ll notice the size doesn’t look right. It’s not. this flat is 2 feet square.


All the parts of a flat have a name. Top & Bottom Rails, A toggle in the middle and a Stile on either side. Each corner is held together with a corner block and the middle toggle is attached with a keystone on each end.


Next step is sizing. Sizing is a powdered substance, which is mixed with water, and then applied with a brush to the muslin of your flat. Sizing tightens the muslin of your flat, while also giving one an impermeable substance so one can paint on it. Instead of sizing it is also possible to use watered down paint. Basically the way one uses sizing is to take a brush and apply, either the watered-down paint, or the sizing mixed with water, to the muslin and when finished let it dry.


Hard covered, Hollywood flat. This flat has the 1″x3″ framing framed “on-edge.” This flat takes up a few more inches in storage but is easier to attach to the flat next to it.


The joints are held together with pieces of wood called keystones or corner blocks. Corner blocks are used to hold the bottom rail, top rail, and both styles in place. Keystones are used to hold the toggle in place. Corner blocks and keystones are glued and nailed to the framing. Due to the manner in which flats are used, the corner blocks and keystones have to be a certain distance away from the edge of the flat. For hard covered flats, flats covered with plywood (usually 1/4″), the distance from the edge should usually be 1″. For soft covered flat, flats that are covered with muslin., should usually be 3/4″. Corner block and keystones have to be placed a width away from the edge so that flats can be joint together at right angles, and the outside could be even.

Flats are usually made in the proportions of 1:2. The most common flats are 4 feet wide and stand 8 feet tall. They are normally framed with 1″ X 3″ pine laid flat. The actual dimensions of 1″ X 3″ are 3/4″ X 2 1/2″

Hard Covers are usually made from 1/4″ plywood or sometimes 1/8″ plywood. The hard flat offers a sturdy wall surface ideal if actors are going to be brushing against the walls.

Soft covers are usually made from a cloth called muslin. To cover your flat staple muslin to one edge of the flat. Glue the width the frame on that side. Then stretch the muslin to the other end and staple it tight. Do the same to the remaining two sides.

After the muslin had been stretched onto the flat wait for the glue to dry. you can then either cut the excess muslin and leave the staples or remove the staples and cut off all muslin other than that on the surface of the flat.

Some comments & suggestions from our visitors:

Nick Spring, Markville Theatrix tells us: Another facing material can be 1/8″ to 1/4″ thin HDF (AKA FIBREX or Masonite) it provides a very smooth surface for painting (with 2 to 3 coats of a primer or with primer paper already applied) and also for wallpapering if needed. I did a production of Sandy Wilson’s “The Boyfriend” in Sept 1997 to Feb 1998 (rehearsal and show) where we needed a look of a mansion on the French Rivera in the 1920’s. The fiberboard held it quite well with a minimal water soak up and warpage (with strategically placed supports and nails/screws) There was a 24 to 48 hour drying period but can be worked with after 26 hours fairly safely with respect to surface damage. it also works out to be lighter as the board is smaller.