The crawlspace is the most difficult, most dangerous, most uncomfortable and most problem-ridden area of most homes. As a result it is my least favorite place to inspect. Home owners seldom go into their crawlspace so unknown problems lurk.
Before I enter a crawlspace I put on knee pads and a respirator. I make sure I have my camera, a couple of flashlights, my moisture meter and a non-contact voltage tester. If I am alone at the inspection, I send a text to my wife of the address and tell her I am going into a crawlspace. That way if I don't text her in 30 minutes that I have exited she can send help.
At the opening to the crawlspace I stop and with my flashlight carefully examine the surrounding. I am looking for animals, electrical wires, water, sharp objects, etc. Once my eyes have adjusted to the dark I move in slowly and look around again. I work my way thru the crawlspace in this way, always stopping to be aware of my surrounding and only moving into areas that I have closely examined before hand.
I examine the outer foundation wall looking for cracks, termites, holes, water penetration, etc. I also examine the rim joist along the edge of the house. I am looking for rot or insect damage. I make sure that the floor joist are properly installed. Between each joist I look at the sub floor from the outer wall to the inner beam where the joist is attached. I work my way around the house in this manner.
Not all areas of every crawlspace can be closely examined. In some cases pipes, metal duct-work or low floor joist prevent me from advancing into a crawlspace. In other cases it is standing water that stops me. As a home inspector I am able to use judgement and not place myself in an unsafe situation.
1. No soil vapor barrier - Ground should have a 6 mil plastic sheet to stop water from rising out of the ground up into the wood beneath the house. Most homes either have no vapor barrier or it is badly deteriorated, improperly installed or incomplete.
2. Mold - Almost all homes have some mold under them. In some cases it is problematic and should be treated by a professional. Mold can only exist in moist conditions, so conditions causing moisture must be lessened.
3. Water penetration - Concrete blocks are very porous and where I live (Central Alabama), almost every home shows some evidence of water penetration. In many cases the problem can be solved or lessened by either grading on the foundation outside the house, adding gutters if they don't exist or extending the downspouts to move water further from house. Occasionally a crawlspace will have standing water.
4. Electrical conditions - Electrical splices outside of a junction box or in a junction box with no cover are very common conditions. It is also common to see electrical wires laying on the ground, not stapled to the underside of floor joists. Frayed insulation or burnt wires are only rarely observed.
5. Evidence of animals - Often animal droppings are seen in crawlspaces. Other evidence of animals include, footprints on plastic, dead animals, skeletons, snake skins and rodent traps.
6. Improper ventilation - Either not enough vent or vents that are not screened allowing animals to enter. Not enough vents is a contributing factor to moisture in the crawlspace.
7. Foundation issues - Cracked, deteriorated or shifted foundations are sometimes seen in the crawlspace. In severe cases this requires examination by a structural engineer.
8. Rotted wood - Water damaged and rotted wood are common in a crawlspace, especially below exterior doors. Sometimes the problem is not very severe and in some occasions the problem is very severe and has caused structural issues.
9. Unprofessional or failing supports - Car jacks, logs, stacks of bricks or rocks, a piece of wood standing on it's end, all of these items are used as supports and they are wrong. Proper supports have sometimes failed, leaving beams that have come loose and fallen.
10. Plumbing leaks - Water drain and supply line leaks and hot water heater leaks are common in crawlspaces.
11. HVAC problems - Duct work that has deteriorated insulation, pinched flexible ducts, or ducts that have come loose are common. Less common but more dangerous are gas flues from gas furnaces or water heaters that have corroded or come loose that are leaking carbon monoxide into the crawlspace.
12. Loose dryer vents - Dryer vents that have come loose or broken that are allowing hot moist air into the crawlspace.
13. Stolen copper - A few times on houses that have been vacant for a while, copper plumbing and HVAC lines have been stolen.
14. Termites - On rare occasion termite tubes and/or live termites are observed in the crawlspace.