BY TIM CARTER Tribune Media Services

DEAR TIM: I’m facing some building projects. One’s a tall deck, another is framing a garden shed, and then I need to help a friend with a room addition. I’m wondering about diagonal bracing. I don’t understand it and need to know why it’s important. Is there a short cut? Can you give me the executive summary so I don’t have any problems on these jobs? —Randy P., Kokomo, Ind.

DEAR RANDY: You’ll be getting the executive summary, all right. Books have been written about diagonal bracing. It’s a very complex topic, but I’ll do my best to give you the basics so you don’t have a failure on any of your projects.

Diagonal bracing is a structural component of just about any building. It provides lateral stability, preventing the collapse of walls, decks, roofs and many other structural elements.

When professional carpenters build a house, they install different types of bracing. One might be a metal diagonal bracing from the lower corner of a wall up to the top plate.

Plywood or oriented strand board, properly nailed, will also provide excellent diagonal bracing. You typically only have to put one full sheet of plywood at each corner of a wall to provide the needed stability.

Insufficient diagonal bracing causes many decks to collapse. I’ve seen decks whose outer support beam just rests on wood posts. If a group of people up on the deck start dancing and a harmonic motion builds up, the entire deck can collapse as the deck starts to shift sideways. Diagonal bracing prevents this side-to-side movement.

There are any number of ways to install diagonal bracing for a deck. One way is to put diagonal braces that connect the deck beams to the vertical posts. These braces are typically cut at a 45-degree angle. It’s really important to bolt these rather than relying on nails.

You can also install a flat 2-by-6 or 2-by-8 on the underside of the floor joists to give the decking great diagonal support. Drive no fewer than two 16d galvanized nails through the brace at each floor joist. Be sure the nails have the proper coating to match the treated lumber you’re using to prevent corrosion.

Diagonal bracing is really important if you’re working with roof trusses on that upcoming room addition. Many a carpenter has been killed or seriously injured when roof trusses suddenly collapse as they’re erected. Wind can easily push them over if they have no bracing.

Large truss roofs often come with detailed drawings that show bracing that needs to be installed in the webs of the trusses. Always be sure to reference any drawings or talk with an engineer at the truss company if you have any questions.