How to Replace Deck Boards

Over time, the boards on your wood deck may begin to rot, split or come loose. If the wood deck is not maintained with regular cleaning staining and sealing, etc., it will be more likely to rot or come loose. Loose decks may only require a few screws to be tightened to repair. But if they have rotted or cracked, it’s time to replace them. This is an easy DIY project that does not require a permit. In most cases, it is not necessary to rebuild the structure of the deck. This is because outdoor deck posts and joists are not directly exposed to the elements and usually last longer than deck boards. You will save a lot of time and money if you only replace the damaged deck boards instead of the entire deck.

What is the cost of deck board replacement?

The cost of replacing deck boards depends on the amount you need to replace and the price of the material. A pressure-treated 5/4 (1-5/32 inch) deck board that is 6 inches wide and 16 feet long will cost about $23. A similar cedar decking board would cost about $58, and a similar composite decking board would cost about $42. A 5-pound box of #10 3-1/2-inch coated deck screws (about 240 screws) would cost about $27. The same screws cost almost twice as much if they are made of stainless steel.

Required Tools

• Circular Saw / Jigsaw / Oscillating Multitool / Reciprocating Saw
• Screw Gun / Power Drill
• Speed Square
• Wood Chisel
• Claw Hammer
• Pry Bar / Cat’s Paw
• Eye Protection
• Paint Brush
• Tape Measure
• Pencil

Materials needed

• Replacement Deck Boards
• Coated or Stainless Steel Deck Screws
• Wood Sealant / Stain (only for use on wood decking)

The new decking board should look the same as the one you already have. If you don’t know what kind of wood is being used, cut it up to make sure. Redwood, cedar, and pressure-treated wood all have their own odor. For composite decking, you need to find the manufacturer or brand name of the composite decking and then match the color and style on the company’s website or in the store.

How to remove and replace decking from a deck

To remove a bad deck

Find the deck boards that need to be replaced. If you don’t want to get the whole board off, decide where to cut it. Set the cutout at least one joist space away from the end of the board next to it, and make sure the remainder of the old board and the new board will cover at least two joist spaces. Use a pencil and a quick square to mark the cut line. Use a circular saw to cut out the broken decking boards so that they are flush with the joists or along the centerline of the joists. To complete the cut without notching the boards next to it, use a jigsaw with a straight blade or an oscillating multi-tool. If you are cutting along the centerline of the joist, remove any nails or screws from the cut line or move the cut line to avoid them.

When you remove a board with a pry bar, put a block under it so it doesn’t damage the board next to it. If you can’t get the screw head out because it’s stripped, you can use an oscillating multi-tool or reciprocate saw to bring it flush with the joists. Use a cat’s claw to pull out or cut out deeply stuck nails.

Checking joists, posts, and columns

When the decking is removed, the joists and cross members are visible. Check for rot or other damage, and make sure they are attached to the posts and sill plates in a secure manner. Also look at the joists for rot, especially if they are touching the floor. Check that the joist hanger is straight, rust-free, and not missing any fasteners. If you find rot in a structural member, you’ll need to decide whether to repair it or replace it, and you’ll also need to learn how to avoid and stop future rot.

Add support cleats and reinforcing joists

Add cleats or sister joists, if you need them, to help keep the new deck boards in place and to reinforce damaged joists. Use framing nails or structural screws to attach cleats/braces to the existing joists, i.e., the deck boards you cut down and other areas where joists need to be reinforced. Make sure the top of each cleat/bracket is level with the top of the already existing joist. Seal the tops of the joists to prevent them from rotting.

Cut boards for the new deck

Find the spacing of the existing deck boards. If possible, span this distance with a plank and leave a 1/8″ gap at each end to allow for expansion. Each plank should span at least two joists, and each plank should be cut differently. Avoid making cuts that will leave knots at the ends of the planks.

Apply stain (optional)

Applying paint or stain to new decking planks can extend their life for many years. It will also make the new boards look more like the old ones. If you are using pressure-treated wood, which does not take paint or stain well, you may need to let the boards dry for a few weeks before painting them. The stain or paint will also stick better if you sand the boards first. Make sure to cover both ends of the boards. Mix one (1) cup of baking soda with one (1) gallon of water, apply it to the wood and rinse it off. This will give the wood a weathered look that matches the other boards. Allow the boards to dry before you coat them and set them in place.

Installed deck boards

Install new boards with the bark side up so that the grain pattern is convex. This will stop the boards from denting. Use 3-1/2″ long deck screws to hold the boards in place. Pilot holes will make the job easier and help prevent the boards from cracking, especially at the ends. When putting the new planks in place, make sure there is the same amount of space between each pair of planks.