Replace a Fence: Project Walkthrough

1. Decide what happens to the old posts before you order a container

Walk the existing fence line and check whether the old post holes are usable. If the new fence follows the same layout and the old concrete footings are sound, sitting at the right depth, and not heaved or cracked, reusing them (cutting the old post off flush and setting a new post sleeve, or breaking out just the post itself and reusing the hole) saves real digging and concrete on the new side. If the layout is changing even slightly, or the old footings are shallow, cracked, or frost-heaved, every one of them has to be broken out and hauled away, and that changes the debris estimate substantially before a single new post goes in.

This decision has to happen before the dumpster size calculator run in step 2, because old post concrete is the single heaviest thing likely to go in that container, and whether it's going in at all depends entirely on the reuse decision made here.

2. Size the container on debris, not on fence length

Run the dumpster size calculator with the actual teardown quantities: linear footage of old pickets, rails and posts as lumber, plus the broken-out footing concrete entered separately as general debris rather than folded into the lumber estimate, since concrete is far denser than wood per cubic yard and the calculator weighs the two very differently. See estimating demolition debris for how to convert a fence run's linear footage into the volume figures the calculator actually wants.

A container sized only on the visible fence material — the boards and rails everyone can see standing before demo starts — routinely comes back undersized once the old concrete footings are broken out and added to the same load, which is exactly the feedback loop the next section works through with real numbers.

Why 2.5 cubic yards of broken footing concrete can bump the container size

Take a 220-foot run of privacy fencing coming out — roughly 34 posts on 6.5-foot centers, with pickets and rails adding up to around 1,320 linear feet of lumber once everything is counted. That lumber alone works out to about 7.9 cubic yards of loose debris and a little over a ton, which the dumpster calculator sizes at a standard 10-yard container with plenty of margin on both volume and weight.

Now add the old post footings, entered as general debris rather than lumber: 34 footings at roughly a foot in diameter and two and a half feet deep work out to around 2.5 cubic yards of broken concrete once dug out. That's not a heavy addition by weight — well under a ton on its own — but it's enough added volume to push the combined total past 10 cubic yards. The calculator's container recommendation jumps a full size, from 10 yards to 20, on the volume line alone, even though the weight total for the whole load still fits comfortably inside a 10-yard container's tonnage limit. Order the container off the lumber estimate alone, and the footing concrete you didn't count is exactly enough to overflow it.

3. Demolish and load, heaviest material last

Pull pickets and rails first, then posts, breaking each post's footing out at the base with a digging bar or a small breaker rather than trying to lever the whole footing out intact — a 10-inch-diameter concrete cylinder several feet long is heavier than it looks and easier to remove in pieces. Load lumber first so it settles into the bottom of the container, then load concrete last on top, since concrete's weight is what a container's tonnage limit is usually calculated against, and an overloaded container gets refused or surcharged at the transfer station regardless of how much visual space is left in it.

Call your local utility locating service before digging out any footing near where a gas, water, or electrical line might run close to the old fence line — a service that's typically free and takes a day or two to schedule, which is worth building into the timeline rather than discovering the need for it mid-demo.

4. Confirm the property line hasn't drifted before resetting posts

An old fence is not proof of where the property line actually is — fences move slightly over decades of repairs, and a replacement built precisely on the old line perpetuates any error the original installer made rather than fixing it. If there's any doubt, or if the new fence is a different height or style that might draw more attention from a neighbor or the local zoning office, confirm the line against a survey or plat map before setting new posts, not after concrete has cured around them.

What happens when the container gets ordered before the footings are inspected

Order a dumpster off a quick look at the standing fence and skip walking the line to check the old footings, and the shortfall shows up mid-demo, once every post is already cut off and the concrete is sitting in a pile with nowhere to go. A container that's already full past its fill line either gets left half-loaded while a second, smaller container is arranged — a delay measured in days on most rental schedules, not hours — or it gets overloaded, which many haulers flag and surcharge, or refuse to take at all if it's visibly over the fill line.

The same problem runs the other way with concrete for the new posts: ordering bagged concrete off the old fence's post count assumes the new layout uses the same number of holes, which isn't true wherever a post is being relocated to true up the line or wherever an old footing turned out to be reusable. Run the fence calculator against the confirmed line from step 4 and take the new post count from there, not from what used to be standing.