Removing Concrete Deck Footings
In construction we use concrete footings in deck construction and to support some areas of residential construction that do not have full foundations. Footings provide support for your deck with live and dead loads and transfer those loads to concentrated points with the ground. In the remodeling and construction world that I live in mistakes sometimes happen. This article will show you some tips to use when removing concrete deck footings with out an excavation machine.
Removing Concrete Deck Footings
Removing Concrete Deck Footings is best done with a excavator, back hoe or even pull it out with a truck or tractor. There times when you simply cant get a machine or truck into a space, or don’t have access to a machine. In this case you need to remove it manually.
We recently had an employee use the wrong size concrete tube pier on a project. To add insult to injury he placed the j-bolt off-center. Dealing with an off-center J-bolt is a discussion for another article which you can read here: How to Repair Concrete Deck Anchor Bolt
My guys debated with me the possibility of adding onto the footing, using a rebar and a larger tube, even adding a second pier. I decided it was best to remove it and start over. The key to removing concrete deck footings is to dig them out so they’re loose in the hole, and then pull them out using leverage as a mechanical advantage. Mechanical advantage is a measure of the force amplification achieved by using a tool, attached to or positioned on a fixed point. [fulcrum]
Steps in Removing Concrete Deck Footings
- Ensure that the structure is supported, remove the footing post if applicable.
- Using a spade shovel manually excavate around the footing at least 3/4 the way around and at least 2/3rds of the length of the footing.
- Dig until you see the footing wiggle a bit. The more you dig the easier the footing will come out. Digging is the easy part, its lifting that is difficult.
- Use a chain long enough to wrap around the concrete footing diameter at least twice. Use grab hooks on the chain to secure it to itself.
- Slide a 6-foot rock bar through the chain.
- Use block of wood as a fulcrum under the rock bar and lift the footing out of the hole. Additional chains can be used to help pull the footing out of the ground. See example
- If a tree, structure or even your truck is nearby, you can use a come-a-long hand winch cable puller to help pull out the footing. The use of the winch provides pulling power and allows you to hold the footing in place while you reposition the chain or add height to your fulcrum.
Tip: We bought a 5/8″ coupling and an eye bolt to attach to the concrete deck footings j-bolt. Once installed on the j-bolt we attached the come a long to the eyebolt and to a web tow strap wrapped around a nearby tree. The tow strap protects the tree, and provides length to our winch. The tree use a secure foundation to pull from. The use of the coupling and eyebolt helped us get the footing half way out of the hole. We eventually needed to relocate the winch cable to the lower chain for better leverage and to get the footing out.
Breaking Up The Footing For Disposal
Once the footing was removed we wanted to split it in half to reduce its size so we could easily carry it to a dumpster. Using an SDS hammer drill we drilled several 3/8″ holes through the middle diameter, rolling the footing two or three times in order to drill a few or more holes.Place a brick, 4×4 or block under the middle of the footing next to these holes.
Hold one end of the footing on the ground and hit the end in the air with a sledge hammer.Fill in the hole or in our case install a new, larger footing.
Compact the Soil
One issue with removing a footing and installing a new one is the soil around the footing is now disturbed. Once soil is removed from its original location, it tends to increase in volume because there is less pressure holding the soil particles together. This soil is no longer compact virgin soil but fill now that it has been disturbed. When the soil is later placed as fill to make a grade change it is still in a “loose” state and needs to be compacted. Make sure to compact the soil, in 8-12-inch lifts as you fill in surround the new footing. We also compact the new hole / inside of the footing tube with a 4×4.
Deck and Porch Safety
Read our Deck Safety – Repair or Replace article