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Savannah Foundation

Serving Savannah and nearby areas

Crawl Space Moisture in Savannah, GA

A damp or musty crawl space in Savannah is a slow threat to the wood that holds up your floor, so get a free inspection and a written price to dry it out.

Call now: (912) 771-1041 or book your free inspection online

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Local to Savannah

We connect property owners in Savannah and nearby areas, including Historic District, Victorian District, Thomas Square and Midtown, Ardsley Park, Isle of Hope and Thunderbolt, with one independent local foundation repair specialist.

  • Humid most of the year

    Savannah averages about 72 percent relative humidity across the day. Mornings average about 86 percent. Those are 1961 to 1990 averages. Air that wet comes in through crawl space vents every day.

  • Water just below the dirt

    USDA soil maps put the water 12 to 30 inches down for months each year in Ocilla soil. In Leon soil it can be 6 to 18 inches down. A crawl space floor sits right on top of that wet ground.

  • The rot line

    A U.S. Forest Service lab paper says wood will not decay below about 20 percent moisture. It will decay above 30 percent. Damp crawl space air can push floor wood into that range.

What it costs

Typical published ranges for Savannah. The contractor's written estimate is the price, and the inspection is free.

WorkTypical range
Crawl space moisture check and written estimate Free
New ground cover (vapor barrier) $1,500 to $4,000
Crawl space dehumidifier $750 to $1,700
Seal the crawl space (encapsulation) $2,000 to $15,000
Remove standing water $2,000 to $10,000
Mold removal $500 to $2,000
Wood rot repair $750 to $5,000

See typical foundation repair prices in Savannah

What a damp crawl space looks like

You may never go under your house. But a wet crawl space tells on itself. The signs show up inside, and you can see more from the access door with a flashlight.

A musty smell

In the house, worse on hot, sticky days.

Wood floors that cup

Or gap more in summer.

Floors that feel soft

Near a bathroom or kitchen.

Sweating ducts or pipes

Dripping onto the ground.

Insulation hanging down

Or lying wet on the dirt.

White fuzz or dark spots

On the joists and beams.

Puddles or mud

After rain that last for days.

A high reading

On a cheap humidity meter inside the house, even with the air on.

Why Savannah crawl spaces stay wet

Three things work together here. The air is wet. The ground is wet. And storms add more water.

The air. Most raised homes in Savannah have vents in the crawl space walls. In summer, warm, wet air flows in. As it hits the cooler ground and wood, it gets even damper, says building science research. That damp settles on the wood, the ducts and the pipes. It is the same reason a cold glass sweats on a hot porch.

The ground. The Chatham County plan calls the county flat, with soil that drains poorly. Water sits close to the top. In some soils it is only a foot or two down for months at a time. So the dirt floor of the crawl space gives off moisture all day.

The storms. Big rain fills crawl spaces fast. In August 2024, Tropical Storm Debby dropped about 10 inches of rain on Savannah. Water that gets under a house in a storm like that can take weeks to dry on its own.

When it is a small problem and when it is urgent

Usually small: A faint smell on the most humid days. Some light surface mold on a few joists. Damp dirt, but no puddles. Insulation that is dry and in place. This is worth fixing, but it is not an emergency.

Get it looked at soon:

  • Standing water that does not drain in a day or two.
  • Wood that is dark, soft or crumbly when you press it.
  • A floor that feels spongy or has started to dip.
  • Mold growing on a lot of the wood, not just a spot.
  • Brick piers that are wet, cracked or losing mortar.
  • Water that came in during a flood or a big storm.

Wood rots when it stays wet. A U.S. Forest Service lab paper puts the safe line near 20 percent moisture in the wood. Above about 30 percent, it will decay. Damp crawl space air can push the wood past that line over a long summer.

What the fix usually is

The fix depends on where the water comes from. A good inspector finds that first. Most jobs use one or more of these:

  1. Fix the water outside. Gutters, downspouts and soil that slopes toward the house send water under it. Sometimes a drain is needed.
  2. Cover the ground. A thick plastic ground cover keeps the dirt from adding moisture to the air.
  3. Dry the air. A crawl space dehumidifier pulls water out of the air and drains it away.
  4. Seal the crawl space. This is called encapsulation. The vents are closed, the walls and ground are covered, and the air is dried. It is the biggest fix.
  5. Repair the damage. Wet insulation comes out. Moldy wood gets cleaned. Rotted joists or beams get replaced or reinforced.

One Savannah detail matters here. In flood zones outside city limits, the Chatham County flood law says the space under a raised home needs flood vents. It also says sealing that space and cooling its air goes against the law's intent. So a fully sealed crawl space is not right for every home. Ask the inspector how the flood rules apply to your address.

What it costs

The cost table on this page shows typical ranges from a national cost guide. They are not quotes. Your price depends on the size of the crawl space, how easy it is to get into, and how much wood needs repair.

What to do before the inspection

Take photos

From the access door, with the date.

Note the smell

Write down when it is worst.

Check after rain

Look for puddles the next day and again two days later.

Look at gutters and downspouts

Note any that overflow or dump next to the wall.

Do not crawl into standing water

Near wires or a furnace.

Find your flood zone

If you can. It changes which fixes make sense.

Frequently asked questions

Is some moisture in a crawl space normal?

A little is normal in Savannah. The ground is damp and the air is humid. The problem is moisture that stays. Standing water, wet wood, mold on the joists or a smell in the house all mean it is too much.

Why does my crawl space smell musty only in summer?

Summer air holds more water. When it comes in through the vents and touches the cooler ground and wood, it gets even damper. Mold and mildew grow faster in that air, and the smell rises into the house.

Should I close my crawl space vents?

Not on your own. Closing vents without a ground cover and a way to dry the air can make things worse. If your home is in a flood zone outside city limits, the Chatham County flood law also requires flood vents under raised homes. Ask the inspector what fits your house.

Can I just put down plastic myself?

A ground cover helps, and some owners do it. But a thin sheet with gaps and no sealed seams does not stop much. It also does not fix a wet spot from a leak or poor drainage. Find the source of the water first.

Is crawl space encapsulation worth it in Savannah?

It can be for homes outside a flood zone with steady damp problems. It seals the crawl space and dries the air with a dehumidifier. In flood zones, county rules can limit it. The inspector can tell you which way makes sense.

Will a wet crawl space hurt my floors?

Over time, yes. Damp wood swells, grows mold and can rot. Soft floors, sagging and cupped wood floors are common results. Catching it early costs much less than replacing joists.

Get your crawl space checked for free

A damp crawl space does not fix itself, and summer comes back every year. Call (912) 771-1041 or send the short form. A local crew will look under the house, find where the water comes from, and give you a written price before any work starts.

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Common foundation repair problems in Savannah

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