Get to know this hidden but important part of your home
Your home’s crawl space is a fundamental but often forgotten component of your home’s safety and structural integrity. Crawl spaces are susceptible to water intrusion, pest problems, mold, radon, and structural damage. An annual inspection can help ensure your crawl space stays dry, clean, and safe. Use our crawl space inspection checklist to guide you through the process.
Homeowners should conduct regular crawl space inspections, ideally every year. The exceptions are if you suspect termites after heavy rain and flooding or if your crawl space smells. If you find issues during your inspection, consult a local professional inspector for a comprehensive assessment for fixes and repairs. It is a good idea to follow up on these issues at least twice a year. If you discover radon in your crawl space, you may need to continuously measure for it using an installed device.
"Look for signs like cracks in the walls, floors, or foundation itself, doors and windows that stick or don’t close properly, and uneven floors. If you see any of these, it’s time for a professional inspection. While you can do a basic visual inspection yourself, significant findings should always be checked by a professional to assess the extent of any issues."
— Tim O'Shea - The Build Pros
We won't sugarcoat the process. There is a reason why pros typically handle these inspections. You will face a barrage of dust, debris, and potential hazards that make this project physically demanding—equipping yourself with the right gear is the only way to handle any surprises. Supplies to have at the ready include:
Coveralls or work clothes
Gloves
Mask or respirator
Goggles
Moisture-resistant shoe covers
Knee pads
Flashlight or headlamp
Work light or portable floodlight
Portable exhaust
Tape measure
Moisture meter
Infrared thermometer
Small pry bar
Digital camera or smartphone
Notepad or inspection report forms
Ziplock bags
Swabs
Small airtight containers
Radon detector kit
One of the most common issues for crawl spaces is excess moisture. Moisture problems can form due to a few different factors, including groundwater intrusion, leaky plumbing or burst pipes, poor drainage, and cracks or gaps in the crawl space’s exterior walls.
Signs of excess moisture include:
Visible pools of water, especially around the perimeter of the crawl space or under plumbing pipes
Discoloration or staining on wood, concrete, or finished walls
Condensation on surfaces, including walls, ducting, and insulation
Evidence of pests, which are drawn to areas with high moisture levels
Using a moisture meter can help you determine if your crawl space moisture levels are too high. If they are, hire a crawl space contractor to assess the problem. You may need to install a dehumidifier or encapsulate your crawl space to keep moisture levels down.
Many crawl spaces have ventilation to reduce moisture levels, keep fresh air circulating, and vent out gases and vapors that the ground releases. Check to make sure your vents are clean, free of obstructions, and open to the recommended angle. Vents that aren’t working properly can cause mold growth and wood rot, so evaluating ventilation is a key component of crawl space maintenance.
Crawl spaces are particularly susceptible to mold growth, which is why it’s so important to ensure moisture levels are low and ventilation is working properly. Mold in the crawl space can spread further into the house, cause serious health problems, and lead to structural damage over time.
To check for mold, look for growth on crawl space components, especially on wood or insulation. Mold spores can be black, green, brown, gray, or white, so any color growth may be cause for concern. A moldy crawl space will also have a pungent, musty odor. Always wear a mask or respirator while inspecting your crawl space, but if you can smell a foul, musty odor through the respirator or outside of the crawl space, you likely have a mold problem.
Mold remediation should be handled quickly and by professionals. Do not attempt DIY mold remediation. Call a mold remediation specialist as soon as you find evidence of mold so that the problem can be handled safely and thoroughly.
High moisture levels, access to the outdoors, and a relatively undisturbed space make for a perfect environment for insects, spiders, rodents, and even small wildlife. If your crawl space provides all these appealing factors, pests will likely move in. Check for these signs of pests:
Spider webs, especially high up and in the corners of the crawl space
Nests made of organic matter, insulation, and other material
Droppings or urine stains
Gnaw marks or holes in crawl space components
Termite damage is the most dreaded type of pest activity, and crawl spaces are a common place for termites to start their destruction. Look for thin mud tubes extending up exterior or interior walls from the ground—subterranean termites use these to get from their nests into your house. Also, check for damaged or hollow-sounding wood. As termites eat their way through wood, they leave small holes, maze-like tunnels, and crumbling sections of wood.
Your crawl space gives you access to much of your foundation, so it’s a good idea to check all accessible structural elements during your inspection.
Foundation walls: Examine your foundation walls for cracks and signs of buckling, bowing, or shifting.
Floor joists: Look for joists that are warped, sagging, or show signs of termite or water damage.
Beams and support posts: Check that beams and support posts are straight, level, and properly connected. Also, look for signs of damage or rot.
Subflooring: Look for sagging or damaged subflooring and ensure subflooring is properly secured to the floor joists.
Check access doors and hatches to ensure they’re functioning properly and fully sealed to prevent pest and animal entry. Look for gaps around access points that could allow moisture into the crawl space.
Radon is a naturally occurring gas that can be emitted from the crawl space soil. Radon can cause serious health problems, so testing to ensure you don’t have radon in your crawl space can help keep you and your family healthy.
Purchase a radon test kit from your local home improvement store or check to see if your state offers free radon test kits. These kits are placed in the crawl space for several days or up to three months (check the test kit instructions). Once the test period is up, you’ll send the test to a lab for results.
Performing a visual crawl space inspection twice a year is something homeowners may be able to tackle on their own, but there are some situations that should prompt you to call a pro who can inspect your crawl space. Hire a professional home inspector if:
You are concerned about your health, safety, or physical ability to safely perform your own inspection.
You’ve found signs of mold, structural damage, or other serious problems.
You don’t have all the tools and equipment to complete a thorough inspection.
A crawl space inspection pro will be able to conduct a thorough inspection and will be well-versed in local crawl space code requirements. A pro can spot existing or potential problems and recommend any necessary repairs or upgrades. The cost of crawl space repairs is a small investment to keep your crawl space safe, dry, clean, and part of your home’s long-term well-being.
