Since crawl spaces are out of sight, they’re easy to ignore. But issues in the crawl space can quickly spread into your home, affecting its air quality, energy bills, and structural integrity.
Catching red flags early can save you from expensive repairs and protect your family’s comfort. Here are five clear signs it’s time to take a closer look at your crawl space.
1. Musty Odors
A musty smell that won’t go away is one of the first (and most noticeable) signs of a crawl space problem. Musty odors typically come from mold and mildew growing in the crawl space.
Air in a crawl space doesn’t stay stagnant; eventually, musty odors travel up into your living space. Don’t brush off musty odors, as they’re often accompanied by mold spores which can lead to allergies or even respiratory issues amongst vulnerable family members.
2. High Indoor Humidity
Without extensive waterproofing measures in place, your crawl space lets in water from the ground and moisture from humid weather. When this happens, the air under your home becomes damp and humid. That humid air then rises up into your house, making your whole home more humid too.
Indoor humidity should be between 30-50% to feel comfortable. But when humid air from your crawl space gets into your house, indoor humidity can go above 60% as seen with a humidity monitor.
This makes your home feel sticky and uncomfortable. It also makes your air conditioner work much harder to cool your house, increasing your energy bills as a result.
3. Sagging or Bouncy Floors
Floor problems occur when wood rot and moisture decay floor joists, the beams that support floor boards. Watch for floors that sag or feel uneven when you walk on them. If your floors bounce or make squeaking sounds, that's a problem too.
You might also notice doors that stick or won't close right. These are clear signs that your crawl space foundation has taken a significant, even structural amount of damage.
4. Mold Growth, Wood Rot, or Pests
Sometimes the best way to check for crawl space problems is to shine a flashlight down there. If you have moisture issues, you'll probably see the damage right away.
Look for mold growth, which shows up as fuzzy white or green spots on wooden beams. Watch for wood rot too, dark areas where the wood feels soft and crumbly. You might also see pests like droppings, spiderwebs, or even live animals under your house.
All of these problems happen because of too much moisture. If you see even one of these warning signs, it's time to take action.
5. Cold Floors in the Winter
If your floors feel cold during winter, your crawl space probably isn't sealed properly. Cold air gets in through gaps and vents under your house, making your floors icy and chilly to walk on.
This happens because outside air flows into your crawl space and then up into your home. You might notice that some rooms feel colder than others, or that your feet get cold even when you're wearing socks or slippers.
Cold floors are a clear sign that your crawl space needs better insulation from insulated doors to foam insulation on the walls to air sealing with vent covers. Once you fix these problems, your floors will feel warmer and your heating costs will go down.
Common Causes of Crawl Space Problems
Understanding what is a crawl space and what causes these problems helps with prevention and long-term solutions. Most issues stem from moisture, which creates conditions for mold growth, high humidity, wood rot, and pest infestations.
The main sources of crawl space moisture include:
- Poor exterior drainage directing water toward your foundation
- Clogged gutters and downspouts overflowing near the house
- Plumbing leaks from pipes inside the crawl space
- High groundwater levels during wet seasons
- Open crawl space vents allowing humid air inside
Addressing these causes with proper waterproofing tools keeps your home healthier and your crawl space functional.
How to Fix Crawl Space Problems
Your crawl space is a critical component of your home's overall health. If you catch and fix issues early, you’re more likely to avoid serious damage. Here’s what you can do.
Install Waterproofing Solutions
Updating your crawl space with waterproofing tools is the best way to keep the area dry. Crawl Space Door Systems helps you protect with our quality-made products. We recommend installing these solutions:
1. Crawl Space Doors
Good access doors are your first defense against crawl space problems. Our crawl space doors are made from ABS/UV treated plastic that won't rust or rot like metal or wood doors. They come in sizes from 12"x32" up to 24"x36" with 3-inch mounting frames. The doors seal tightly to prevent humid air from entering - stopping mold growth before it starts. This keeps your family healthier and saves you thousands in mold remediation costs. You can choose doors with or without built-in louvers for controlled ventilation.
2. Flood Vents
These special flood vents protect your foundation from flood damage while preventing everyday moisture problems. They're ICC-ES certified and FEMA-approved, automatically opening when water rises, then closing tight afterward.
Each vent covers 303-305 square feet and measures 8.25"H x 16"W. Installing these can lower your flood insurance premiums while keeping your crawl space dry year-round.
3. Vent Covers
Vent covers give you complete control over moisture entering your crawl space. Our recessed and outward-mounted covers seal existing foundation vents to block humid outside air, the main cause of crawl space moisture problems.
Made from strong ABS plastic, they install easily with basic tools. By stopping moisture at the source, you prevent mold, wood rot, and pest infestations that cost thousands to fix.
4. Exhaust Fans
These powerful fans actively remove problem-causing moisture from your crawl space using standard 115V/120V household power. Our portable and wall-mounted fans move between 340 to 1,115 cubic feet of air per minute (CFM).
They run continuously to eliminate the stagnant, humid conditions where mold thrives and wood rots. This protects your home's structure and improves air quality throughout your house. Exhaust fans are especially important since around 50% of the air in your home comes from the crawl space.
5. Dehumidifiers
Professional-grade dehumidifiers maintain healthy humidity levels and protect your biggest investment - your home. They can remove 120 pints of moisture per day and feature high COP (Coefficient of Performance) ratings for energy efficiency.
These units prevent the 60%+ humidity levels that cause mold growth, wood rot, and structural damage. By keeping humidity between 30-50%, you protect your family's health, reduce energy bills, and avoid costly repairs in the future.
6. Vapor Barriers
Our 10-mil thick vapor barrier covers your crawl space floor and walls completely, creating a moisture-proof seal. They prevent water vapor from seeping in through the dirt floor and foundation walls.
A properly installed vapor barrier can reduce crawl space humidity by 70% or more, protecting your home's structure and eliminating the damp conditions that attract pests, allow for mold growth, and lead to structural issues.
Can I Do DIY Crawl Space Repair?
Yes, maintenance, minor repairs, and installation can be handled by a motivated homeowner with the proper tools and know-how. Besides the sense of accomplishment of a job well done, DIY repairs are usually less expensive than working with a professional contractor.
When Professional Help Makes Sense
Even though crawl space waterproofing measures can be installed by homeowners, certain situations may require professional expertise. Consider hiring professional help in these instances:
- Extensive mold or wood rot damage
- Structural repairs to floor joists or supports
- Standing water or drainage problems
- Pest infestations requiring specialized treatment
- Safety concerns about air quality or structural integrity
Professionals have the proper safety equipment for more intense repairs, and access to commercial-grade tools. If a DIY project seems too difficult, it may be worth calling in an expert.