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How to Make a Theatre Flat or Scenery Flat

Meghan is a huge theatre buff. She loves everything from being onstage to building sets behind the scenes.

A set construction crew, hard at work to build their set.

A set construction crew, hard at work to build their set.

When it comes to building a set for a play, a flat is just about the most basic element. Flats are used to represent walls on a set, and with a new coat of paint, each one can be used multiple times for multiple plays.

Here is a step-by-step guide for building a hard-backed flat for all your theatrical needs.

A theater flat. (PLEASE NOTE: this drawing is NOT to scale.)

A theater flat. (PLEASE NOTE: this drawing is NOT to scale.)

Key Terms

See diagram. This represents the back of the flat. The front will be covered by one 4'x8' sheet of lauan, which is inexpensive 1/4" plywood.

  1. Stile. The long sides of the flat. 1"x3" lumber cut to fit. The stile should be 8' long minus the width of the top and bottom rails.
  2. Rail. The top and bottom of the flat. 1"x3" lumber cut to exactly 4'.
  3. Cornerblock. 9" by 9" 1/4" plywood cut diagonally to make triangles. The outer grain of the wood should run diagonal to the joint when placed.
  4. Toggle. The center brace(s) of the flat. 1"x3" wood, cut 4' minus the width of the two stiles. You may use one centrally-placed toggle or two toggles equally spaced between the rails.
  5. Strap. Secures the toggle to each stile. 8" x 2 3/4" 1/4" plywood.
  6. Diagonal Brace. Secures the rail and stile together. 1"x2" lumber cut to fit. One diagonal brace should be sufficient, but you may use two if you'd prefer.
  7. Half-Strap. Secures the diagonal brace to the flat. 1/4" plywood.

Step 1. Measure and Cut

Measure and cut the lumber to fit your needs. For a standard 4'x8' flat, measure your 4' rails first. Do not assume each piece of lumber is a standard size--be sure to make each measurement individually and carefully.

Lay out your rails flat-side down; that is, not on their edges. The top of one rail should be eight feet from the bottom of the other. Determine the length you need for your stiles (usually around 7' 6 1/2") and cut those pieces as well. REMEMBER: Measure twice, cut once.

With your rails and stiles in place, you can now make measurements for your toggle and corner brace. Your flat should be 4' by 8' altogether, so make your measurements exact.

Do the same with your cornerblocks, straps, and half-straps. Remember that your cornerblocks are triangles and will need extra care in cutting.

Step 2. Assemble Your Pieces

You'll be building your frame before you attach your front lauan. Assemble your pieces as shown above, measuring again and making sure everything is exactly in place before you attach anything.

How to attach a cornerblock for flat construction. NOTE: Not to scale.

How to attach a cornerblock for flat construction. NOTE: Not to scale.

Step 3. Attach Your Cornerblock

The first things you must attach when building a flat are your rails and stiles using your cornerblock pieces. If you need to set aside your toggles and straps, you can do so at this time. Follow the diagram to the left to determine how to properly attach your cornerblock for maximum support.

Place your cornerblock (as well as your straps) 3/4" from the edge of your flat to allow for 90 degree butt to other flats.

The grain of your cornerblock should run diagonal to the brace.

You may attach your cornerblock with small nails; however, appropriately-sized drywall screws will be easier to work with. Because you're working with 1'x3' lumber, you'll need to use very small screws for this work.

Step 4. Attach Your Straps

After your external frame is in place, you may want to check in with your lauan to make sure everything is squared up. Place it under your frame so that when you attach your toggles, they'll make things line up as you'd like. You'll need to attach the straps to keep your toggle and diagonal brace in place. These will keep your frame from shifting left-to-right and add extra security and weight to your flat. Mirror your screws or nails on either side of the joint to provide appropriate support.

Step 5. Attach Lauan

Once your frame is built, flip it over and attach your 4'x8' sheet of lauan to the front of the flat. Line up all corners and pieces before you nail or screw in any part of the lauan to assure everything is measured out properly.

Step 6. Assemble and Paint

Now that your flat is constructed, use it to build a larger set. There are a number of ways to properly brace your flats, depending on your theater and space. Once you've got your flats and other pieces assembled properly, paint and decorate your set accordingly, and break a leg with your performance!

Next Steps

Set construction can be a challenging and fun experience. Many people have built before and many more will build in the future. Don't feel like you need to re-invent the wheel. There are many resources out there for you. We recommend the Backstage Handbook. It probably contains more information than you'll ever need, but it's still a great place to start.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

© 2012 Meghan Hopper


Michael Nolan from Sarasota, FL on April 02, 2015:

I give this my stamp of approval. Great hub!

Meghan Hopper (author) on July 19, 2013:

You can cut them yourself, just as you would with a stile. Cutting down smaller scrap pieces of plywood should do it.

morton on July 19, 2013:

where do you get corner blocks?