Basement Waterproofing in Manchester, NH

Manchester basements, straight answers

The biggest city in New Hampshire, built on a river and a millyard, and most of its housing is older than the people living in it.

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The river runs the whole show

Manchester sits on the Merrimack, and the USGS gauges it just below the city at Goffs Falls (USGS station 01092000, Merrimack River near Goffs Falls, below Manchester, NH). When that river comes up, the water table across the low ground comes up with it.

The city grew downhill toward the water. The millyard and the older neighborhoods around it sit lowest, and those are the basements that flood first and dry out last. Get up onto the higher wards and the same spring is a nuisance instead of an event.

Snow does the rest. About 53 inches falls over a Manchester winter (NCEI 1991-2020 normals, via Current Results, nearest station Massabesic Lake). It melts in March into ground still frozen underneath, so it cannot soak down. It runs sideways instead, into the loose soil packed against your foundation, and it comes up at the floor wall joint.

The dirt against your wall

Here is the part nobody explains at the estimate.

When your house went up, a crew dug a hole, set the foundation and pushed the same dirt back in around it. That backfill never packs down the way the ground beside it did. It stays loose for the life of the building. Loose soil drains slowly and holds water right against the wall, which is why water shows up at your foundation and not out in the middle of the yard.

Frost heave spends every winter leaning on those walls and working the floor wall joint a little wider. That joint is a cold seam between two separate pours. It was never watertight to begin with.

Old brick, old stone, and a lot of triple deckers

Manchester housing is the oldest we work in outside of Lowell. The middle of it lands around 1964 and the neighborhoods near the millyard run far older. Barely a third of the housing here is a detached single family house, and under half of households own the place they live in.

So most of what we walk into is a two family, a triple decker, or a converted mill building, and the foundations are brick or stone as often as they are poured. That matters for the fix. On stone and brick, water works through the face of the wall and the mortar between, and it shows as damp patches partway up rather than a clean line at the floor. The vapor barrier carries more of the load on those walls. The drain and the pump still do the same job.

If you rent, the water belongs to your landlord and we are happy to talk to them. If you own the building, understand what the water is actually costing you. It is sitting against the sill and the posts that carry every floor above it, and rot in that framing is a far larger bill than drainage. (Housing age and ownership figures are in the sources below.)

What it costs to waterproof a basement in Manchester

$3,000 to $30,000 for a full system.

Perimeter drain length is the main driver, then the floor condition and whether you want a battery backup. A single wet wall in a small basement is a different job from a full perimeter under a three unit building. Free inspection, free estimate, written quote inside 24 hours. Hearth handles financing if you want it, subject to approval, and we make nothing on it.

How the Forever Dry System keeps it dry

A full perimeter drain along the inside edge of the floor at the floor wall joint. One 1/2 hp sump pump for every 120 feet of that drain. A vapor barrier on the walls. A dehumidifier so the air dries out and not just the slab.

100% dry for life or we come back free of charge, and it transfers to the next owner under our conditions. The sump system carries 3 years, batteries excluded.

Take the battery backup in this city. The storm that puts the river up is the storm that drops power on your street, and a charged backup moves roughly a residential pool’s worth of water before it needs charging. Battery only. We do not sell water powered units.

We do not dig up the outside. On a Manchester lot there is frequently no room to, and where there is, the dig settles and fails inside two or three years. Interior drainage lasts because you can reach it and service it.

If your basement is dry and you have one crack, we will fill the crack and leave. You do not need a system for that, and we will not pretend you do.

The parent service here is basement waterproofing. We also cover crawl space encapsulation, radon mitigation, basement finishing and foundation crack repair in Manchester. Sagging floors point at a different job, priced out in our guides to lally columns and sill beam replacement.

What we hear from Manchester homeowners

Two things come up on nearly every call in this city, and both are worth answering before you spend money.

The first is the sump that was already there when you bought the place. Somebody dropped a pump in a hole years ago with nothing feeding it. It handles a damp corner and it has handled every year until this one. Then a wet spring arrives, water comes in twenty feet from the pit, and the pump sits there dry while the floor is soaked. That pump is not broken. It never had a drainage system behind it, and adding the drain to the pump you already own is usually cheaper than starting over.

The second is the finished basement somebody put in before you got there. Studs and drywall straight onto a wall that was never dried out. You cannot see what is happening behind it, and by the time the smell reaches the stairs the framing has been wet for a long time. We open a section, look, and tell you honestly whether it is a drainage job or a demolition job. Sometimes it is both, and you should hear that from us at the estimate and not halfway through the week.

Work we have done nearby

Old New England housing stock, and the two things that go first on it. These are different houses, not one job photographed start to finish.

Frequently asked questions

What a recent customer said

I initially called 603 Basement Solutions when my basement was flooding during a recent rainstorm. Brenden came out and put a temporary solution in place. He explained options for a permanent sump pump system. He handed me off to Justin for scheduling. The installation crew, Gerald, John, and Kelvin came out several days later. They were very courteous, professional, and did an excellent job.

Tom Walsh, 5 stars, Google review

Sources

Merrimack River streamflow: USGS 01092000, Merrimack River near Goffs Falls, below Manchester, NH. Snowfall: NCEI 1991-2020 normals, via Current Results (nearest station Massabesic Lake, 52.8 in/yr). Housing age and tenure: US Census ACS 2023 5-year, tables B25035 (median year structure built, 1964), B25003 (49% owner occupied) and B25024 (36% single unit). The cost range, the warranty and what goes into the system all come from 603 directly.