Water or humidity? Start there
A wet crawl space in Chattanooga usually has one of two problems, and plenty of homes have both. Liquid water comes in from rain, runoff and saturated soil, and it collects at the low spots. Water vapor rides in on humid outside air through the foundation vents and rises out of the dirt. Waterproofing handles the liquid water. Encapsulation handles the vapor. When you have both, the water gets handled first, because sealing a crawl space that takes on water just traps the water inside.
Signs water is getting in
- Standing water or puddles after a hard rain
- Mud, or soil that stays soaked for days
- Water lines, stains or a white chalky crust on the block walls and piers
- Old plastic with water pooled on top of it
- A smell that gets worse after storms
Signs it's vapor, not water
- A musty smell that is worst in summer
- Ductwork, pipes or insulation that sweat or drip in July and August
- Damp wood and mold spots, but no puddles
If it's only vapor, you don't need a sump pump, and we'll tell you that at the evaluation. Crawl space encapsulation or a sealed crawl space vapor barrier fixes it on its own.
How Foametix waterproofs a crawl space
- On-site evaluation. We get under the house, find where the water comes in and where it collects, and take moisture readings. You get a written price before we touch anything.
- Look outside first. Gutters, downspouts and the grade around the house cause a lot of crawl space water. If a downspout dumping at the foundation is the real problem, we'll point it out.
- Sump pump at the low point. We dig a sump pit where the water collects, set the pump, and run the discharge line out away from the foundation so the water doesn't circle back.
- Seal and encapsulate. With the water handled, we close the vents, seal the rim joist with spray foam, foam the foundation walls, and lay a heavy liner across the floor, taped at every seam and wrapped up the piers.
- No dehumidifier. Once the water has somewhere to go and the outside air is shut out, there's nothing left for a machine to fight.
- Foundation vents closed and sealed
- Rim joist sealed with spray foam
- Spray foam on the foundation walls
- Heavy liner over the floor, taped at the seams and run up the walls and piers
- Sump pit and pump at the low point, where the water collects
- Discharge line carries the water out and away from the house
Why a sump pump alone isn't enough
A sump pump moves water that has already gotten in. It does nothing about the humid air coming through your foundation vents all summer, and in Chattanooga that air is often wetter than anything coming out of the ground. That's why a pump-only job can still leave a crawl space smelling musty. We pair the pump with a full seal so the space stays dry in every season.
Why we still don't install a dehumidifier
A lot of waterproofing packages end with a dehumidifier in the crawl space. That machine runs on your power bill, needs servicing, and eventually needs replacing, and the whole time it's treating a symptom. We close every path the moisture uses instead: the water leaves through the pump, and the vents, rim joist, walls and floor get sealed. When nothing wet is getting in, there's nothing for a dehumidifier to do.
Where crawl space water comes from around Chattanooga
Most of the water we find starts outside. The clay soil here drains slowly, so after a heavy rain the ground around a foundation can stay saturated for days. Homes built into a slope, which describes a lot of houses on Signal Mountain, Lookout Mountain and Missionary Ridge, take runoff on the uphill side. And downspouts that empty right at the foundation put roof water exactly where you don't want it. The pump handles what still gets in, and fixing the source outside makes its job easier.
Quick check: walk around the house during or right after a hard rain. Anywhere a downspout empties within a few feet of the foundation, or the ground slopes toward the house, is a likely place your crawl space water is coming from.
Common questions
Do I need a sump pump in my crawl space?
Only if liquid water is getting in: standing water, mud, or water lines on the walls. If your crawl space is damp or musty but never wet, sealing it fixes the problem without a pump, and we'll tell you so at the evaluation.
Can you waterproof and encapsulate in the same job?
Yes. The sump pump goes in first, then we seal the vents, rim joist and walls and lay the liner, so you end up with one dry, sealed crawl space.
Will a sump pump get rid of a musty smell?
Not by itself. Musty smells usually come from humid outside air and moisture rising out of the dirt, and a pump doesn't touch either one. Sealing the crawl space is what clears the smell.
Do you put a dehumidifier in after waterproofing?
No. Once the water drains to the pump and the crawl space is sealed, there's no moisture source left for a dehumidifier to fight.
What does crawl space waterproofing cost?
It depends on where the water comes from, the size of the crawl space and how much sealing it needs. The evaluation is free, and you get a written price before any work starts.
Who does the work
Foametix is veteran-owned and has been insulating and sealing homes around Chattanooga for more than 17 years. The same crew that looks at your crawl space is the crew that does the work, not subcontractors.
Find out what your crawl space actually needs. Free on-site evaluation, written price before we touch anything.
Call 423-710-2529 Request an evaluationRelated: crawl space encapsulation · crawl space vapor barrier · why a dehumidifier won't fix a musty crawl space · is encapsulation worth it?