What Your House Is Built On: Panama City Foundation Repair

Establishing whether a Panama City house sits on native ground or placed fill runs $300–$900 by hand probing, with the elevation survey free. Florida Building Code 1804.6 requires fill deeper than 12 inches under a shallow foundation to follow an approved geotechnical report.

The two natural grounds in Bay County, the third one that was delivered by truck, and the paperwork that is supposed to exist.

The two natural grounds foundation repair here has to deal with

The USDA soil survey for Bay County is public, specific, and almost never consulted by the people it would help most. It maps the ridges and the flats as genuinely different materials.

Series	Composition	Behaviour under a house
Foxworth sand	93–96% sand, 0.25–1.25% organic matter, to 80 inches	Stable. Carries load and keeps carrying it
Pamlico muck	About 50% organic material to roughly 32 inches, sand beneath	Compresses under load, slowly and permanently
Dorovan muck	50–60% organic material to 60 inches, sand beneath	The same, with further to go before it finds bottom

Both muck series are mapped as very poorly drained, which is the survey’s way of saying they formed in standing water. That is also why they are organic: material accumulated faster than it decomposed. It is excellent wetland and poor bearing.

The third ground, which arrived on a truck

A great deal of developed low ground here is not native soil at all. It is fill, placed to raise a lot out of the flat, and it is the most variable material on any site because its quality depends entirely on how carefully it was put down.

Fill placed in thin lifts and compacted to a tested density is genuinely good ground. Fill pushed into place in one go, with whatever was on hand, is a settlement problem waiting for a load. Both look identical from the driveway once grass has grown.

The rebuild after Hurricane Michael, which struck near Mexico Beach on 10 October 2018 with 160 mph sustained winds, put an unusually large number of new pads on this ground in a short period. That is context, not an accusation — but it is why a house built in 2021 can be moving while one from 1962 is not.

The report that is supposed to exist

This is the part most homeowners have never been told. Florida Building Code section 1804.6 requires that where shallow foundations bear on compacted fill, the fill complies with an approved geotechnical report. The exception is narrow: fill 12 inches or less in depth need not comply with a report, provided in-place dry density is at least 90 percent of maximum dry density determined per ASTM D1557.

Above that depth, section 1803.5.8 sets out what the investigation must specify: site preparation, the material to be used, test methods for maximum dry density and optimum moisture content, maximum lift thickness, field test methods, the minimum acceptable in-place density, and how many field tests are required and how often.

So if your house sits on a raised pad, a document describing all of that was contemplated by the code. Three places are worth asking: the building department that issued the permit, the builder, and your own closing file. Full detail on the fill and compaction page.

What we can establish, and what we cannot

• We can probe by hand to find the depth of placed fill and the top of natural ground in the first several feet, at several locations
• We can read the mapped soil series for your parcel and tell you what the survey expects to be there
• We can measure your floor and tell you what the structure has actually done
• We cannot drill borings, run laboratory testing, or issue a geotechnical report — that is a different licence and a different firm
• We cannot tell you what is 40 feet down, and any contractor who offers to is describing a map rather than your lot

What you are built on, answered plainly

What does a soil and fill assessment cost?

Hand probing to establish whether you are on native ground or placed fill runs $300-$900 depending on how many locations. The elevation survey that comes with it is free. Actual soil borings are geotechnical work and we refer those out rather than pretending otherwise.

What is Florida Building Code 1804.6?

It requires compacted fill under a shallow foundation to comply with an approved geotechnical report. The exception covers fill 12 inches or less in depth, which need only reach an in-place dry density of at least 90 percent of maximum dry density per ASTM D1557.

So a report should exist for my house?

If the pad it sits on is more than 12 inches of placed fill, yes - Section 1803.5.8 sets out what that investigation has to specify. Whether a copy survives is another matter, but the building department, your builder, or the closing file are the three places worth asking.

How do I know if my lot was filled?

Often the lot tells you. A pad noticeably higher than the road or the neighbours, a driveway that climbs, retaining at the property line, or a house whose crawl clearance differs front to back. Older aerial imagery of the parcel is also surprisingly informative.

Does being on fill mean there is a problem?

Not at all. Properly placed and compacted fill in lifts, tested as it went in, is excellent ground and behaves better than some native soils. The question is never whether there is fill - it is whether it was engineered fill or whatever was available.

Can you tell me what is 40 feet down?

No, and neither can anybody without a rig. We establish what is in the top few feet by probing, which is enough to answer most homeowners' questions. Deeper than that is a geotechnical investigation and requires a firm licensed to do it.