Soft or bouncy floor: a lost pier, or a wet subfloor

A floor that gives underfoot is one of the two things people notice first in a settled manufactured home, the other being a door that has started to stick. It has two very different causes and they feel the same from above. A lost pier is $75 to $150 to reset or $150 to $400 to rebuild; a wet subfloor is carpentry quoted after the area is opened, plus $300 to $800 to patch the belly that let the water in.

The two causes

A lost pier. The floor over that spot is no longer being supported. On Sumter County’s sandy ground, the usual sequence is that the pad presses into the sand, the pier goes slack, the load it was carrying transfers to the neighboring piers, and the floor between them flexes. You feel it as a soft or bouncy patch in one area.

A wet subfloor. Water has reached the decking from a torn underbelly, a plumbing leak, or a roof leak, and the material has lost strength. This one feels spongier rather than springy, and it usually keeps getting worse in the same spot rather than staying stable.

Often both. A torn belly lets water at the ground under the piers as well as at the subfloor, so the same water problem produces both symptoms.

Check this first

1. Walk the area and map it. One spot between two points, or a whole strip along one side of the room?
2. Do the marble test in three rooms. Consistent direction everywhere means the frame is low on that side, which is the sloping floor problem. One room going its own way points at a local pier or a soft patch rather than whole-home settling.
3. Press it hard, and listen. Springy with some bounce-back tends to be support. Spongy, with the floor covering feeling detached, tends to be material.
4. Look for water clues. Staining, a musty smell, cupped vinyl or laminate, a toilet or tub nearby, or a ceiling stain above.
5. Check nearby doors. Sticking doors in the same area point at frame movement.

Then look underneath, or have somebody look, because that is where the answer actually is.

What we look for from below

Under a lost pier: a visible gap between the cap and the frame, a leaning or cracked block, a pad pressed into the sand, or a pier you can rattle by hand. A pier you can move is carrying nothing, and its load went to the pier next door, which is how failures spread. Around Wildwood we also find pads that landed half on a limestone boulder and rock on it, and piers an installer shifted a foot to get around rock, leaving the beam unsupported where the manual wanted a pier.

Under a wet subfloor: a torn, sagging, or missing underbelly, insulation hanging down, staining on the decking, damp material, and often signs of animals, because a torn belly is an invitation.

Cause, fix, and cost

Why Sumter County ground produces the pier version

The soil survey maps the higher ground around Wildwood and Oxford in Candler, Arredondo, Kendrick, and Tavares sands, loose and well drained, and the lower ground in Sparr and Adamsville with a seasonal water table at 23 to 33 inches through the summer. Sand under a concentrated pier load migrates and compacts once it has been wet; saturated sand yields. The Lisbon climate station normals put 55 percent of the year’s rain into June through September, and the pier under the wettest patch of ground goes first.

The lag is the part people find confusing. A lot stays wet in August, the sand compacts under a pier, and the floor starts feeling soft the following spring. The cause and the symptom are months apart.

That is also why three to five years is an honest maintenance interval here rather than a sales interval, and at the short end if the ground under the home stays wet.

Do not jack it yourself

A bottle jack under a soft spot loads the frame in a place that may not be designed to carry a point load, and lifting one point on a home that is already out of level transfers stress into walls, plumbing, and the frame itself. Cracked drywall and broken drain lines are the common outcomes; a slipped jack under an occupied home is the uncommon one.

In Florida this is licensed installation work under section 320.8249. The installer licensing page covers how to verify a license before you let anyone put a jack under your home, including us.

When to call

When the spot is getting bigger, when it is near a bathroom or kitchen, when there is any water history nearby, or when doors in the same area have started sticking. Tell us where the soft area is, how big it is, whether it is getting worse, and what the marble test showed. The level check is free and includes getting underneath, which is where this question actually gets answered. Prices are on the pricing page, and pier and pad repair and vapor barrier replacement go deeper on the two fixes.

We cover Wildwood, Oxford, Lady Lake, Bushnell, Coleman, Webster, and Leesburg.