Crawl space foundation repair: sagging floors, supports and cost

Signs you may need crawl space foundation repair

• Sagging or bouncy floors
• Sticking interior doors
• Musty smells, mold or wet insulation under the house
• Rotted joists, sill plates or wooden posts

How crawl space foundation repair is done

1. Inspect beams, joists, posts and moisture levels
2. Add adjustable steel support jacks under sagging beams
3. Sister or replace damaged joists and beams
4. Fix the moisture: vapor barrier, drainage, dehumidifier or encapsulation
5. Remove mold if present

How much crawl space foundation repair costs

Moisture is usually the root cause, so many quotes combine structural supports with a vapor barrier or encapsulation. Ask for the structural and moisture parts priced separately.

Source: HomeGuide, Foundation repair cost (updated Feb 2026); HomeGuide, Crawl space encapsulation cost (updated Jan 2026). Checked October 2026.

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Crawl space repair near you

Many companies that list crawl space repair are waterproofing firms. For sagging floors, ask whether they install structural supports themselves.

Before you hire

• Ask how many support jacks, where, and on what footings
• Ask for structural and moisture work as separate lines
• Ask for photos of the crawl space before and after

Permits, codes and licensing

Contractor licensing is set by each state, and some leave it to cities or counties. Some states license this work at state level (for example the CSLB in California, the Registrar of Contractors in Arizona or the DBPR in Florida); others only require registration or local licenses. Check the license or registration number on your state's or city's public lookup before you pay a deposit, and ask for proof of liability insurance.

Companies that offer crawl space foundation repair

728 companies in the directory name this repair on their own website (the quote is on each company page); they are listed first in each state. Another 0 are companies that usually offer it but don't say so online – confirm when you call.