Crawlspace
Drainage
If there is water under your house after it rains, nothing else you do down there will hold. Drainage comes first: get the water out, keep it out, and every repair above it lasts longer.
Water gets in
three ways
Before we install anything, we work out which of these you actually have, because the fix is different for each and most homes have more than one.
Surface water. Rain that lands on the roof and the yard and runs toward the house instead of away from it. Downspouts discharging at the foundation, flowerbeds built up above the slab, and grading that has settled over the years are the usual culprits.
Groundwater. Much of this area sits close to the water table, and in some areas groundwater is even affected by the tides. Rain makes the water table rise and fall, and water comes up through the soil under hydrostatic pressure. No amount of gutter work fixes that; it needs a drainage system and a pump.
Humidity condensing. Not liquid intrusion at all, but it leaves the same wet surfaces. Warm outside air meeting cool surfaces in a vented crawlspace condenses, which is why drainage and encapsulation are usually sold together and genuinely belong together.
Signs the water
is winning
You do not have to see a puddle for water to be doing damage. These are the tells we check on every crawlspace inspection.
Standing water or wet soil
The obvious one. Any water that remains a day or more after rain means the space has no way to drain and is functioning as a basin.
Water lines on piers
A discolored horizontal band on block piers or stem walls is a high-water mark. It tells us how deep the water gets even when we visit on a dry week.
Efflorescence on block
The chalky white crystalline deposit on masonry is mineral left behind by water moving through the block. It is direct evidence of ongoing water transport.
Rusted supports and fasteners
Rust on jack posts, straps, ducts and fasteners means sustained moisture contact. Corroding steel supports are a structural problem, not a cosmetic one.
How we get
the water out
A drainage system is only as good as its weakest link, so we size and install the whole system together, synced with a sump pump, so that when water enters the crawlspace it is immediately pumped back out.
Questions we
get asked
Do I need a sump pump in a crawlspace?
Only if groundwater is a continuous problem in the crawlspace will a sump pump be recommended. The crawlspace is usually the lowest point on the property, and gravity drains do not work in crawlspaces, so if standing water or a rising water table is a problem under your home, a sump pump will be required.
Can I just put plastic down over the wet ground?
No. A vapor barrier stops soil moisture from evaporating upward, but it does nothing about liquid water arriving under pressure. Lay a liner over a crawlspace that floods and you get water sitting on top of the plastic, where it cannot even evaporate, and you have made a shallow pond that you can no longer see.
Drainage first, then the barrier. Always that order.
Will drainage work stop my crawlspace smelling musty?
It removes the water feeding the smell, which is the necessary first step. The odor itself comes from microbial growth on damp organic material, so lasting results usually need drainage plus humidity control — the space sealed and held at a humidity where that growth cannot continue.
Keep reading
Crawlspace Encapsulation
The other half of the job: sealing the space and holding humidity where rot cannot progress.
ReadCrawlspace Stabilization
Repairing what long-term moisture has already done to the framing and supports.
ReadFoundation Repair
Water is the leading cause of foundation movement here. See what it does to a footing.
ReadStop bailing out
the same crawlspace
We will find where the water is coming from, in what order to deal with it, and what it costs. Free inspection and a written plan.