Wet-Set, Dry-Pour or Foam: How Fence Posts Should Be Set in Broward's Sandy Soil

One of the most common worries we hear from homeowners watching a crew work is some version of: they tipped dry concrete mix into the hole, didn't mix it, and moved on — is that right? Sometimes it is a legitimate method. Sometimes it's a shortcut. The difference matters more in Broward County than almost anywhere, because our soil is sand over a high water table and our fences have to stand up to hurricane-force wind.

What sand changes

Clay and loam grip a post. Sand does not; it flows around a post that's being pushed and offers very little resistance on its own. That means the footing — its depth, its diameter and how well it's bonded to the post — is what actually holds the fence up. Our earlier post on why sandy soil is hard on fence posts explains the damage side; this one is about getting the footing right in the first place. The high water table adds a second constraint: in many yards you hit water a few feet down, which limits depth and means the hole is often wet before any concrete goes in.

The methods, honestly compared

• Wet-set concrete. Concrete is mixed to a proper consistency, placed around the braced post, and finished with a crown so water sheds away. This gives the most consistent strength through the full depth and the best bond to the post. It needs bracing while it cures and panels generally wait until it has. For a solid privacy fence in a high-wind zone, this is the benchmark.
• Dry-pour. Dry mix is poured into the hole around the post and water is added from the top, or the ground moisture is left to hydrate it. In Broward's damp sand it often does cure, but it cures unevenly: well at the bottom where it's wet, poorly near the top where it's dry and where the wind load is greatest. It is quick and it is widely used for lighter fences. For a tall solid fence facing hurricane wind, it's a compromise, and if it was done without adding any water at all, it's worth raising with the installer.
• Expanding foam. Two-part foam that expands to fill the hole. It's fast, light and popular with vinyl installers because posts can be adjusted for a short window. It grips the post well; its grip on loose sand is the question, and its track record under repeated storm loading is shorter than concrete's. Where it's used, hole depth and diameter still have to do the work.
• Driven steel posts. Steel posts driven deep without concrete work well in sand for metal-framed systems, because the depth and the steel provide the resistance. The approach doesn't transfer to wood posts or vinyl sleeves, which need a footing.
• Tamped sand or gravel only. You'll see people point out that utility crews set poles with no concrete. Those poles go many feet into the ground. At fence-post depth in Broward sand, a tamped hole does not reliably resist wind on a solid fence.

What a wind-ready footing looks like here

Whatever the method, the things that make a Broward footing hold are consistent: a hole deep enough for the fence height, wide enough that the concrete has sand to bear against, concrete that reaches up to just below grade and is crowned to shed water, vinyl posts reinforced internally and set in concrete rather than foam alone where wind exposure is high, and post spacing that matches the product's wind-load approval. Broward is in a high-velocity hurricane zone, and the approved installation details for a given fence product usually specify depth, diameter and spacing for exactly this reason. The method should match that specification, not the crew's habit. Our post on why vinyl panels blow out in hurricanes shows what happens when it doesn't.

Questions worth asking before the holes are dug

• How deep and how wide will the holes be for this fence height?
• Will the concrete be mixed, or placed dry? If dry, how will it be hydrated?
• How long will the posts cure before panels go on?
• Will the footings be crowned above grade or finished flat?
• What does the product's wind-load approval say about post spacing, and does the quote follow it?

A good installer answers those without hesitation. If the answers are vague, that's useful information too.

The Bottom Line

In Broward's sand, the footing is the fence. Wet-set concrete to the right depth and width, crowned and cured, is the standard for a solid fence that's expected to meet a hurricane. Dry-pour and foam have their place on lighter, more open fences, provided depth and diameter aren't skimped. If you'd like a quote that spells out exactly how your posts will be set, call (754) 255-2096 or see our wood fence installation page.