Frequently asked questions

In almost every case, because water in the surrounding soil has nowhere better to go. Rain and snowmelt saturate the ground around the foundation, pressure builds, and water moves through the weakest available path — a crack, a mortar joint, the joint where the wall meets the floor, or up through the slab.

Heavy rain saturates the soil faster than it can drain away. The soil against the foundation holds that water, hydrostatic pressure rises, and the wall and slab are pushed on from outside. Once the soil drains down, the leaking stops — which is why the basement seems fine again a few days later.

That joint — the cove joint — is a seam between two separately poured elements, not a sealed connection. It's one of the lowest points in the basement and one of the easiest paths for water under pressure. Seepage there is extremely common and is a drainage problem rather than a structural one.

The pressure that standing water in saturated soil exerts on whatever is holding it back. Water is heavy, and when the soil around your foundation is full of it, that weight pushes against the walls and up under the slab. Relieving it — by giving the water an easier route — is the whole idea behind interior drainage.

A trench cut into the perimeter of the basement floor at footing level, containing perforated pipe surrounded by washed stone and pitched toward a sump basin. Water reaching the base of the wall enters the stone and pipe and travels to the sump instead of onto the floor. Concrete is restored over it.

Water collects in a basin set into the floor. As the level rises it lifts a float switch, which starts the pump. The pump pushes water up a discharge pipe and out of the building. When the level drops, the switch turns the pump off. A check valve stops discharged water from draining back in.

It depends on your walls. Damp block or stone walls often benefit — a barrier directs that moisture down into the drainage system instead of letting it evaporate into the room. Sound poured concrete may not need one. It's a call best made after looking at the wall.

Paint and sealers are applied to one face of a wall that has water pressure on the other. They can reduce surface dampness, but they don't relieve the pressure. Water commonly reappears at the next weakest point — often at the cove joint or through the floor.

Many interior drainage installations run two to three days, depending on the length of perimeter, the access to the basement, and what has to be moved or removed first. Smaller jobs — a pump replacement, a crack repair — are often a single day. You'll get a schedule before work begins.

Interior work can generally be done year-round, since it happens inside a conditioned building. Exterior excavation is much more difficult in frozen ground, which is one reason interior systems are the practical choice for a mid-winter problem.

That smell is usually moisture — damp masonry, a damp slab, or humid air with nowhere to go. Exposed soil in a crawl space is another frequent source. Addressing the moisture usually addresses the smell; air fresheners and dehumidifiers alone treat the symptom.

Yes. Concrete is porous, and when the water table rises close to the underside of the slab, pressure can push moisture up through it — through cracks, or as general dampness across the surface. A floor that darkens in patches after rain is often doing exactly this.

The water your drainage system collects has nowhere to go and backs up into the basin, then onto the floor. Because power outages and heavy storms tend to arrive together, a battery backup pump is worth serious consideration on any basement that relies on a sump.

Both work; they solve the problem at different points. Exterior work intercepts water before it reaches the wall but requires excavation, which can mean removing landscaping, walkways and decks, and is weather-dependent. Interior drainage manages water once it arrives, can be done year-round, and doesn't disturb the outside of the house. Access, cost and site conditions decide it.

It depends on the length of perimeter that needs drainage, whether a sump basin has to be installed or an existing one can be used, wall condition, access, and how much has to be moved or removed first. Anyone quoting a firm number without seeing the basement is guessing. Our inspection is free and comes with a written price.