Basement Waterproofing & Leak Repair
in Montgomery County, MD

From the outside, when the goal is a dry wall. Exterior waterproofing stops water before it reaches the foundation: the wall is excavated, repaired, covered with a membrane and protection board, and given drainage at the footing, so the masonry stays dry and so does everything attached to it. Interior systems collect water after it has come through the wall and pump it out; they keep the floor dry but leave the wall wet, which is why finished basements with interior systems still grow mold behind the drywall. Interior coatings and sealers do not hold against hydrostatic pressure at all. Mold Pro Solutions does the exterior work; when a property genuinely needs an interior system, we say so during the inspection.

Because the soil around the foundation is saturated and pushing water through every opening it can find: cracks, the joint where the wall meets the floor, tie holes, porous block, the gap around a pipe. That force is hydrostatic pressure, and it is strongest a few hours after a Montgomery County summer storm, which is why the wet line appears overnight and is dry again by the weekend. What feeds it is usually visible from outside: downspouts discharging at the wall, grading that slopes toward the house, a clogged gutter, a window well without a drain, or an exterior membrane that failed or never existed. Our inspection maps the entry points inside and the water path outside before anything is quoted.

Yes, and the order matters. First the cheap causes: extend the downspouts, regrade the soil to slope away from the house, clear the gutters, put a drain and a cover on the window wells. If the water still comes, the wall itself is letting it in, and the durable fix is exterior waterproofing of the affected length: excavation to the footing, crack repair, membrane and protection board, and foundation drainage to a working outlet. A basement that floods with standing water also needs the drying and the mold work handled; our water damage team does that under the same scope.

It is worth it when the basement gets wet more than once: every wetting feeds mold on the framing and drywall, rots the sill plates and trim, ruins flooring and stored contents, and leaves a smell that buyers notice in the first minute. A dry, documented basement is a usable room and a clean disclosure at resale; a basement with a known water history is a negotiating point against you. It is not worth it as a precaution on a basement that has never been wet; in that case keep the downspouts long and the grading right.

Mold Pro Solutions quotes every project in writing after an on-site inspection, because exterior waterproofing is priced by the wall, not by the square footage of the basement. What moves the number: the linear feet of wall excavated, the depth to the footing, what is in the way (walkways, decks, gas meters, AC units, buried lines), how many window wells are replaced, how far the drainage runs to a working outlet, and how much siding, trim and interior finish the water already damaged. A short section at one corner and an L-shaped excavation along two walls are different projects, and the online per-square-foot figures describe interior coatings and drain systems, which this is not.

No. Standard policies treat waterproofing as maintenance and exclude groundwater and seepage altogether, so the excavation, membrane and drainage are paid by the owner. What may be covered is the interior damage from a sudden, accidental event, a burst pipe or a failed water heater, and the water-backup endorsement covers sump and drain backups when you bought it. Our Maryland mold insurance guide walks through the distinctions; our documentation separates the covered interior work from the waterproofing so the claim is clean. Basement flooding from rain and surface water falls under the same exclusion, which is the question we hear most after a summer storm.

A vertical or diagonal crack narrower than a quarter inch that weeps after rain is a shrinkage or settlement crack and is repaired and sealed from the outside as part of the waterproofing. The signs of a structural crack are different: a horizontal crack, a stair-step crack following the block joints, a crack wider than a quarter inch or one that keeps growing, a wall that bows inward, doors that stick or floors that slope. Those need a structural specialist, and we stop and refer you before any sealing is done; major structural foundation repairs, underpinning and engineered modifications are not part of our scope.

A below-grade membrane protected by a board and drained at the footing is designed to last for the life of the foundation under normal conditions; the components that need attention over the decades are the drainage outlet and the window wells, which must stay clear. Left alone, a leaking wall keeps the framing, insulation and drywall against it wet every season: mold grows behind the finishes, sill plates and trim rot, efflorescence and spalling slowly damage the masonry, and each storm costs another round of drying and cleaning that never addresses the cause.

A finished basement is waterproofed from outside without touching the finishes, which is one of the reasons we work from the exterior: the excavation is in the yard, not in the family room. The exception is the damage the water already did behind the drywall, which has to be opened, dried and remediated regardless of the method. Waterproofing without digging means interior coatings, injections or interior drain systems; coatings do not resist hydrostatic pressure, injections handle a single crack in poured concrete, and interior drains manage water rather than stop it. For a wall that is wet from the soil side, the dig is the work.

We install and repair foundation drainage on the outside: perforated pipe in clean stone with filter fabric along the footing, connected to a verified outlet, plus surface drain boxes and window-well drains, as part of an exterior waterproofing project. Interior French drains and sump-pump systems are not our standard offer; when a property genuinely needs one, we tell you during the inspection and you can source it with a clear scope in hand. Yard French drains for a soggy lawn are landscaping work, not waterproofing.

Yes. The work is outside; you lose the use of the excavated side of the yard and sometimes a walkway or a door for the duration, and the basement rooms along that wall stay off-limits only if interior repairs are part of the scope. A short section at one corner takes several working days; a long or complex excavation along two walls, with window wells, drainage and siding repairs, takes one to several weeks, scheduled around rain and ground conditions. You receive a project-specific schedule after the inspection.

A project estimate is free: when you can show us where the water comes in, a wet wall after storms, a weeping crack, a window well that fills, we inspect it and give you a written price for the exterior work. A diagnostic assessment is different: when the source is unknown, several symptoms overlap, or leaks have survived other repairs, the visit maps the moisture inside and surveys the exterior before anyone can say what the job is; it carries a fee that is credited toward the work if you proceed. We tell you which one applies when you book.

Spring through fall, when the ground can be excavated and backfilled properly and the membrane cures within its temperature range; frozen ground stops exterior work in the coldest weeks of winter. The inspection can happen any time, and the best diagnostic visit is the one made within a day of a heavy rain, when the entry points are still showing. If water is in the basement now, the drying and protection of the finishes come first, whatever the month.

Two causes, and the fix is different for each. Condensation: warm, humid summer air meets a slab and walls that sit at the ground’s temperature and the floor sweats; the water appears on humid days regardless of rain, often under rugs or boxes, and a hygrometer reads above 60%. That is a humidity problem, solved with dehumidification and by keeping the basement closed on humid days, not with waterproofing. Groundwater: water pushing up through the slab, the floor-wall joint or a floor crack after rain or when the water table is high; it tracks the weather, shows first at the lowest point and leaves mineral deposits as it dries. Our inspection reads the moisture pattern and the weather history before anything is proposed.

If the window is still under the manufacturer’s warranty, call the installer or the manufacturer first. For an older window, call us: most rain leaks are not the glass but the envelope around it, failed exterior caulking, missing or damaged head flashing above the frame (the classic rain leaking through the top of the frame), rotten trim or siding that lets water run behind the window, or a sill that slopes the wrong way. Those are repaired without replacing the window: sealants removed and replaced, flashing corrected, rotten trim and siding replaced, and the wet drywall and insulation inside restored. A failed seal inside a double-pane unit, fog between the panes, is a window replacement, which we coordinate. Insurance usually covers the interior water damage from a sudden leak, not the window itself.