A soft or bouncy floor: decking, joists or piers?

A floor that gives underfoot, springs when you walk across it or has a dip you can feel usually comes down to one of three causes in a mobile home: the decking, the joists under it, or the piers under the steel beams. They need different repairs, so the first job is finding out which one it is. We go under the home, read the frame at every pier, and look at the underbelly, joists and the underside of the floor where we can see it. If the piers are the cause, a relevel typically runs $450 to $800 for a singlewide and $750 to $1,400 for a doublewide. You get a written quote after the look.

Three causes, three clues

The decking. Some homes have particle board or similar decking, and when it gets wet it swells and loses strength. The giveaway is a soft patch near water: in front of the kitchen sink, beside the tub or toilet, under a leaky window or by an exterior door. The floor around it is usually level. That is a floor repair, not leveling.

The joists. The floor joists span between the steel beams. A cracked or water-damaged joist makes a soft line running across the home rather than a single spot. We can see joists only where the underbelly is open.

The piers. If the soft or springy area runs along a beam, the floor slopes toward it, and doors near it have started sticking, the beam has likely lost support from a pier. The floor feels soft because, with one pier carrying nothing, the beam spans a longer gap between supports and flexes.

Why North Port homes get here

Two things work against floors here. The first is the ground. The City’s soils are poorly and very poorly drained flatwood sands (EauGallie, Myakka, Holopaw and Pineda), with the water table able to sit within 6 to 18 inches of the surface for part of the year and ponding in low spots. Pads in wet sand can sink, and a sunk pad leaves a beam with a long unsupported stretch.

The second is moisture under the home. If the underbelly is torn and water stands under the home after rain, the underside of the floor can stay damp. Ian put roughly 13 to 21 inches of rain on North Port gauges in 2022, and the City lists the Myakkahatchee Creek, the Myakka River and the canals as its flood-prone areas.

What we do

If water is the root of it, we tell you before we start, because new shims under a home that sits in a puddle after heavy rain may not stay put.

Next steps

Try the relevel cost calculator for a starting figure, or read about pier and pad repair and a full relevel. If the floor started feeling soft after a storm, a post-hurricane inspection covers the piers, straps and underbelly in one visit. Ask whoever does the work for their FLHSMV mobile home installer licence number and look it up.