Crawlspace Health Check: 7 Things Under Your Home That Predict Future Termite Trouble
- Jameson Elam
- 6 days ago
- 6 min read
About the Author: Jameson Elam is the owner and operator of Good Sense Termite, serving Alameda, Santa Clara, San Mateo, and Santa Cruz counties. With over 14 years of hands-on experience in the termite control industry, Jameson specializes in thorough inspections, accurate diagnostics, and long-term solutions tailored to California homes. His deep knowledge of local termite behavior and building structures has made Good Sense Termite a trusted name for homeowners and real estate professionals alike.
Why The Crawlspace Matters More Than You Think
Most Bay Area homeowners never go into their crawlspace. That is fair. It is cramped, dusty, and not exactly inviting. But for termites, that space is prime real estate: dark, quiet, and often damp. By the time you see damage inside the home, the crawlspace usually saw it first.
At Good Sense Termite, we spend a lot of time under homes. Over 14+ years of crawlspace inspections, we keep seeing the same patterns: certain conditions almost always show up before termite problems do.
Think of this as a crawlspace health check. If you fix these issues early, you cut your risk before it turns into damage and repair bills.
Here are 7 things under your home that quietly set the stage for termites.
1. Standing Water Or Damp Soil
If the soil under your home looks or feels wet long after rain or watering, that is a problem.
Common causes:
Poor drainage around the foundation
Broken or redirected downspouts
Low spots under the house where water collects
Irrigation that runs too long near the perimeter
Why it matters:
Subterranean termites need moisture to survive
Damp soil lets them build mud tubes and stay active longer
Persistent moisture also supports fungus that weakens wood
What we look for during an inspection:
Puddles or dark, wet soil
Water staining on foundation walls or piers
Signs that water has been running through the crawlspace
Drying out the crawlspace does not kill an existing colony, but it makes your home a far less attractive place to start or rebuild one.
2. Old Wood, Form Boards, And Debris Left Under The House
Crawlspaces often turn into storage for things that should never be there:
Old form boards from original construction
Scrap lumber or plywood
Cardboard boxes
Leftover trim or siding pieces
Why it matters:
Termites do not care if the wood is part of your house or not
Extra wood on the ground becomes a low effort food source
Once they are feeding under your home, it is easier for them to move into your structure
We often find active termites in loose boards while the main framing is still “clean” on paper. That is a warning shot. Cleaning out scrap wood is simple compared to structural treatment and repair later.
3. Earth To Wood Contact
This is one of the most common conditions we flag.
Examples:
Soil that has built up against wood posts or beams
Support blocks that sit right in the dirt without concrete or metal hardware
Siding or trim that sits below grade or touches dirt in a side yard
Steps, deck posts, or skirting that rest directly on soil
Why it matters:
Subterranean termites prefer to work where they do not have to cross open air
If wood is touching soil, they can move into it with very little risk
These are often the starting points for mud tubes and hidden damage
During a crawlspace inspection, we check:
Where soil is too high
Where form boards or shims touch earth
Any place where wood bypasses the concrete foundation line
Even small adjustments, like lowering grade or adding proper hardware, can make a noticeable difference.
4. Past Plumbing Leaks That Never Got A Follow Up Check
Many homes have had at least one plumbing leak:
A slow drain leak under a tub or shower
A past pinhole leak in a copper line
A failed wax ring under a toilet
A kinked or damaged supply line
The plumbing gets repaired, the floor gets cleaned up, and life moves on. But under the house, the wood around that area may have stayed damp for a long time.
Why it matters:
Long term moisture weakens wood and attracts fungus
Termites are more likely to target wood that has been softened or stressed
A past leak can leave behind damage that never got a proper structural check
When we inspect, we pay special attention to:
Areas under bathrooms, kitchens, and laundry rooms
Spots where staining or corrosion on pipes suggests a history of leaks
Subfloor and joists that look darker or more brittle than surrounding wood
You do not need to panic over every old leak, but it is smart to make sure the structure around it is still sound and termite free.
5. Insulation Hanging Or Touching The Ground
Crawlspace insulation is there to help with comfort and energy efficiency, but it can cause trouble when it is not installed or maintained correctly.
Problem signs:
Insulation batts falling out of joist bays
Insulation touching the soil
Insulation sagging low enough to hide visual access to wood and pipes
Why it matters:
Drooping insulation can trap moisture against wood
It blocks the view of joists and subfloor, making it easier to miss tubes or damage
Insulation touching soil can wick moisture up toward the framing
We often find termites or fungus damage hidden behind drooped insulation that has not been checked in years. Part of a good crawlspace health plan is simply keeping insulation in place, off the soil, and not hiding key contact points.
6. Blocked Or Missing Vent Screens
Crawlspaces need air flow. Vent screens help move air while keeping pests out.
Common issues:
Vents blocked on the outside by plants, soil, or stored items
Screens rusted through or missing entirely
Vents covered from inside by insulation or stored material
Why it matters:
Limited airflow means higher humidity and more moisture retention
Higher humidity helps termites and wood destroying fungus
Missing screens let rodents and other pests in, which can then damage insulation and wiring
During an inspection, we check:
Whether vents are open and clear
Whether screens are intact
Whether airflow seems balanced around the perimeter
Sometimes simple cleaning and trimming give your crawlspace a much better environment with very little cost.
7. Old Repairs That Treated Symptoms, Not Causes
Crawlspaces tell the story of a home’s history. We often see:
Sistered joists or added supports near old damage
Patches on subfloor
Extra posts and blocks that look newer than surrounding material
The question is: was the original cause fixed?
If a previous repair addressed only the damaged wood and not the reason it was damaged, you may see problems come back in the same area.
Examples:
Replacing a rotted beam without correcting high soil and poor drainage under it
Fixing a sagging floor without looking for mud tubes or active termites
Swapping out damaged rim joists while planters still sit against the exterior wall
A crawlspace health check looks at both:
What was fixed
Whether the risk factors that caused it are still present
How Good Sense Termite Approaches Crawlspaces
We do not treat the crawlspace as an afterthought. It is one of the first places we want eyes on.
Our crawlspace approach includes:
Entering the subarea when physically and safely possible
Checking for active termites, mud tubes, and fungus damage
Looking for moisture sources, soil contact, and drainage issues
Documenting conditions with photos so you can see what we see
Explaining which issues are urgent and which are long term maintenance items
For homeowners who are not in active escrow, we provide these inspections at no cost. If your home is in escrow, we offer fee based inspections that meet real estate requirements.
FAQ: Crawlspaces And Termites
Q: Do I need to go into my own crawlspace?
No. Most homeowners are not comfortable in that space, and that is fine. Your job is to have it checked by someone who is trained and equipped to be there.
Q: Can I just dry out the crawlspace instead of doing termite treatment?
Drying out the crawlspace is great for prevention, but it does not remove an existing colony. Both treatment and moisture control matter, just in different ways.
Q: Is it bad to have a little scrap wood under the house?
Even a small amount of scrap wood can encourage termites to settle under your home. It is always best to remove loose lumber and cardboard.
Q: How often should my crawlspace be inspected?
In most Bay Area homes with raised foundations, we recommend at least every 1 to 2 years, or any time you notice floor issues, musty smells, or plumbing leaks.
Final Thoughts: Fix The Crawlspace, Protect The Home
Your crawlspace is out of sight, but it should not be out of mind. The conditions under your home set the stage for either long term stability or future termite trouble.
You do not have to guess what is going on down there. That is our job.
Schedule an inspection with Good Sense Termite. We will check your crawlspace, explain what we find, and help you address risks before they turn into repairs.
It is just Good Sense.
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