Basement Waterproofing in Lancaster, PA

A wet basement usually has a clear cause, and the right fix depends on finding it. We check the outside of your home and the inside of the basement, then recommend what fits, from a downspout extension to an interior drain and sump pump. We work in Lancaster and the towns around it.

How to tell what kind of water problem you have

Damp basements don't all need the same fix. Before anyone talks about drains or pumps, it helps to know which of three things is going on: condensation, water seeping through the walls, or water coming up at the floor. Each has a different cause and a different fix.

Condensation shows up in humid summer months. You'll see beads of water on cold pipes, concrete that feels damp and a musty smell. Seepage tends to follow rain. Look for damp patches that start low on the wall, a white chalky crust on block or poured concrete, and water lines along the joint where the wall meets the floor.

There's a simple test. Tape a square of plastic wrap to the wall and leave it for two days. If moisture forms on the room side, it's condensation. If it forms behind the plastic, water is coming through the wall.

• Damp or dark patches low on the wall after rain
• White mineral crust on block or concrete
• Peeling paint or bubbling on finished walls
• Puddles at the floor joint or around a floor crack
• Rust on the feet of metal shelving, the water heater or the furnace
• A musty smell that a dehumidifier doesn't clear

What usually causes a wet basement

Most basement water is surface water that ended up in the wrong place. A roof sheds a lot of water in a storm. If the downspouts drop it right beside the foundation, the soil there stays soaked. Soil that has settled into a low spot along the wall does the same, and so does a patio or walk that tilts toward the house.

Once the ground beside the wall is saturated, the water presses against the foundation. It finds the weak points: mortar joints in block walls, the seam where the floor slab meets the wall, tie-rod holes in poured walls, and cracks.

Some causes are less common but still worth checking. A footing drain can clog or collapse. A window well can fill up with no way to drain. A low-lying lot can have a high water table. And sometimes a slow plumbing leak looks a lot like seepage.

Repair or a full waterproofing system?

We start with the least expensive fix that has a real chance of working. If water only comes in at one corner below a downspout, extending the downspout and regrading the soil may solve it. There's no point trenching a basement floor for a problem a ten-foot extension would fix.

A full system makes sense in a few cases: water comes in along several walls, it shows up after every heavy rain whatever is done outside, or the outside fixes are already in place and the basement still gets wet. It's also worth considering before you finish a basement, because drywall and carpet don't cope with even small amounts of water.

A single crack in a poured concrete wall can often be sealed from the inside. A crack that is wide, growing or offset, or a wall that bows inward, is a structural concern. A structural engineer should look at it before any waterproofing goes in.

The main ways we keep water out

Most basements need one of the approaches below, and often more than one. Which one depends on where the water gets in, what the walls are made of and what's around the outside of the house.

Interior drain and sump pump

Exterior waterproofing

Grading, downspouts and window wells

What a visit involves

We start outside and look at the gutters, the downspouts, the slope of the yard, patios and walks, and the window wells. Then we go down to the basement. We check where the water shows up, what the walls are made of, whether there's already a sump pit and where it drains.

Photos from the last time it rained are a big help. So is knowing when the water appears: during a downpour, a day later, only in spring, or only when snow melts.

After that we tell you what we think is causing the water and what we would do about it, starting with the smallest fix that could work. If outside work alone might be enough, we'll say so. We go through the options with you before anything is booked.

Basements in Lancaster and the surrounding towns

Lancaster has a wide mix of foundations. Older rowhomes and farmhouses in the city and nearby towns often have stone or brick foundations laid in lime mortar, which softens and washes out over time. Post-war houses tend to have concrete block walls, and water can collect inside the hollow blocks. Newer homes usually have poured concrete. It's tighter, but it still cracks and leaks where the wall meets the floor.

Stone foundations need care. Sealing the inside face too tightly can trap moisture in the wall. In those basements we usually handle the water at the floor with an interior drain instead of trying to make the wall itself watertight. Loose mortar may also need repointing by a mason.

Much of Lancaster County sits on limestone, and many lots have dense clay soil on top. Clay drains slowly and holds water against a foundation long after a storm has passed. Freeze and thaw cycles each winter open small cracks a little wider. Spring is when many homeowners first see water, when snowmelt and heavy rain arrive together. Summer brings humid air, so a basement that stays dry in a storm can still feel damp in July. A dehumidifier deals with the humidity, but it won't fix seepage.