Squaring Up A Deck Frame

The single most important framing member is the ledger board.

Squaring up a deck frame.

If they don t push the two corners that are further away the long measurement back together a little and remeasure. A sagging collapsing or crooked deck is not only unsightly but also potentially dangerous. One way this old house general contractor tom silva ensures that mason s strings and deck framing are square when he is building a deck is by employing the 3 4 5 rule based on the pythagorean theorem. Compare the opposite lengths of the perimeter of squares and rectangle forms these lengths should be the same.

This is a crucial step that must be taken when building a house or when framing a simple deck. Speed squares and framing squares are helpful tools for using in construction builders often use them to check the layout. Then he marks the top of the ledger 3 feet from the corner and the top of the side rim. It s a good idea to mark joist locations on the ledger and on the front facing rim joist before installation when you can lay the framing members side by side on a pair of sawhorses.

Obviously the more square the frame the better. Once installed it acts as a guide for a deck frame that s level and square. As with all structures a long lasting durable and solid deck depends on a proper foundation. Anyone wants to learn the way to square a deck should know the 3 4 5 method as many builders often use it to make sure they are building a square deck.

If the measurements match your frame is square. Use the 6 8 10 or 3 4 5 rule to determine square or right angles in deck porch floor wall or roof framing or any other building framing or construction task to check a single corner for square use the 6 8 10 rule or if the sides are too short use 3 4 5 technique. Using a square and a 4 level will also help verify that your deck form is level. Some guys gals prefer to use the 3 4 5 method or the cross over method i use both.

Slight tolerances can be adjusted before the joists are installed to prevent exaggeration. A common mistake with diy ers is to forget to square the frame up or box. First he tacks a double joist hanger to one end of the ledger and slips a side rim joist into place.