How to Demolish a Deck on a House

Better to remove an unsafe deck than have it fall down.

Age has adverse effects on wood, and an old deck that has served for many years may need to be torn down before it becomes a safety hazard. No matter whether your deck is experiencing symptoms of age, like splitting and lifting boards or wobbling, or you just have a new design concept for your house, take care in the demolition process. Protect yourself from falling off of boards or having them fall on you, and dispose of wood correctly and safely.

Things You'll Need

• Protective gloves
• Safety glasses
• Hammer
• Drill
• Socket wrench
• Wrench
• Crow bar
• Pry bar
• Reciprocating saw
• Sledge hammer
• Shovel

Instructions

1. Start by removing the railings. Unscrew the rails from the posts, or knock them free with a hammer. Remove all screws and pull out all nails, then set the rails aside. Then unscrew the bolts or lag screws holding the posts, remove them, and set them with the rails. Start a pile where all the old wood will be stacked, and keep this pile relatively well organized. This will make disposal easier and prevent accidents.

2. Remove the decking boards, either by unscrewing them or prying them loose with a crowbar or pry bar. Be sure to de-nail the boards before adding them to the woodpile.

3. Remove the deck joists. If they are screwed into joist hangers, remove the screws with a drill. If they are nailed to the tops of the beams, then use a crowbar to pry them loose. If they are nailed to joist hangers, you will probably have to cut through the middle of each joist with a reciprocating saw, then pry each half from the rim joists with a crowbar or pry bar. The joist hanger will come off with the joist, and then you can pry this off the joist with a pry bar. Don't expect to save the joist hangers.

4. Use a socket wrench to unbolt the rim joists from the posts. Unbolt one end, then support this end, or have a helper hold it, while you unbolt the other end.

5. Unbolt the ledger board from the house, if there is one, and remove any flashing that is there. This will leave holes in the siding that will have to be patched and painted.

6. Remove the posts. If these are attached to post holders, remove the screws holding them, or pry the nails out with a pry bar. If the posts are set in concrete, try to wiggle them out of the ground, concrete and all, or pound them loose with a sledge hammer. If you can't get them free, cut them flush to the ground with a reciprocating saw.

7. Dig out the concrete bases of the posts with a shovel. If the deck was built on pier blocks, remove these and set them aside.

8. Recycle as much wood as possible, but if you have to dispose of it, separate pressure-treated wood from non-pressure-treated wood. Check your local ordinances for regulations concerning the proper disposal of pressure-treated wood.

Tips & Warnings

• Old deck wood is a valuable source of landscape lumber. It also makes great firewood, if you can think of no other use for it, as long as it is not pressure-treated. Never burn pressure-treated wood.

• Be sure to de-nail boards as you remove them. This may be tedious, but it can prevent a potentially serious accident.

• Wear protective gloves and eyewear, especially when you use power tools. Splinters abound on old wood, and they can be very uncomfortable in your hands, and dangerous if they get in your eyes.

References

• Bob Vila: Deck Demolition
• Komar: Deck Demolition Derby!