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.

The two causes

A lost pier. The floor over that spot is no longer being supported. On Mohave County’s sandy soil, the usual sequence is that the pad presses into the ground, the pier goes slack, the load it was carrying transfers to the neighbouring 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.

Narrowing it down from inside

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. 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.

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.

Why Mohave County soil produces the pier version

Bullhead City sits on desert alluvium with caliche layers, and that changes pier behaviour in a way sand does not. Caliche is a hard cemented layer, and where a pad bears on it the pier can be very stable; where a pad bears on the looser material above or beside it, it settles into that instead. The result on a single home can be piers that have barely moved next to piers that have dropped noticeably, which produces the twisting and racking that shows up as sticking doors.

The other local driver is water, and out here that means either monsoon runoff or irrigation. Ground that is dry for nine months and then takes a monsoon downpour, or a park lot that gets flood or drip irrigation against the home, behaves very differently under a pier load than steady moisture does.

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. The pricing page covers how to verify a licence before you let anyone put a jack under your home, including us.

What it costs

Published on the pricing page, and the cost calculator prices levelling work from those numbers.

What to expect on the call

Where the soft area is, how big it is, whether it is getting worse, whether there is any water history nearby, what the marble test showed, and whether any doors have started sticking. The level check is free and includes getting underneath, which is where this question actually gets answered.

We cover Bullhead City, Fort Mohave, Mohave Valley, Golden Valley, Kingman, and Lake Havasu City.