What’s the cheapest way to put a drain in a basement?

The cheapest drain that actually keeps a basement dry is an interior perimeter drain tied to a sump pump, and 603 installs that as our Forever Dry System starting around $3,000 to $30,000. It costs less than digging up your yard from the outside, and it lasts. A cheaper patch like a single floor drain or hydraulic cement on the wall may run a few dollars at the hardware store, but it does not move the water that pushes in under your floor. So you pay twice.

Let us walk you through it.

Why water shows up in the first place

When your house was built, the crew dug a hole, poured the foundation, then shoveled the dirt back in around it. That backfill is loose. It drains slow and it holds water against your wall. Add a New Hampshire winter and frost heave pushes the wall inward. Water finds the weak spot, usually the floor wall joint where the wall meets the slab. That is where most basements leak.

So a real drain has to catch water at that joint and carry it away. A drain in the middle of the floor will not do that.

The drain options, cheapest to most durable

A floor drain to a sewer or pit is the cheapest single fixture. It only helps if water is already pooling right on top of it. It ignores the joint where water actually comes in.

Exterior excavation is the most expensive. You dig down the full outside of the foundation and install drain pipe and membrane. We do not do this one, and here is why. In our field experience that fix tends to fail in about two to three years as the soil settles back and the membrane gives. You spend the most and you redo it soonest.

Interior perimeter drainage sits in the middle on price and beats both on staying dry. We channel along the inside footing, route every drop to a sump pump, and pump it out. That is the core of the Forever Dry System. Full perimeter drain, a sump pump sized at one half horsepower per 120 feet of drain, a 12-mil wall vapor barrier, and a dehumidifier. It is 100% guaranteed to be dry for life!

What drives the price

Three things move the number. How many feet of wall we drain. Whether your slab is thick or has obstacles we cut through. And add-ons like a battery backup pump. A charged backup battery can move about a residential pool’s worth of water, roughly 15,000 to 20,000 gallons, on a power outage. Our backup is battery, not water-powered.

You do not need every add-on. If you have one wet corner and a dry rest of the basement, say so. We will tell you if a partial run covers it. We would rather scope it right than sell you the whole perimeter you do not need yet.

If your problem is actually a crawl space and not a finished basement, that is a different job. Crawl spaces get crawlspace encapsulation, not the Forever Dry System. See /crawl-space-services/ for that.

Why not just the hardware store fix

Hydraulic cement, sealer paint, a bag of patch. Those are cheap and they feel like progress. They block a little surface seepage. They do not relieve the water pressure building under your slab and behind your wall. The water comes back through the next weak spot. The cheapest path that holds is the one you only pay for once.

We back the Forever Dry System with a full transferable lifetime warranty. The sump pump system carries a 3-year warranty, batteries excluded, and the dehumidifier carries 5 years. See /the-603-guarantee/ for the details.

Want the real number for your basement? We do a free inspection and a free estimate, and you get the quote within 24 hours. Financing is available through Hearth, subject to approval, and we make nothing on it.

Call us at 603-610-1770 or book your free inspection. We will measure your basement, find where the water gets in, and price the drain that keeps it dry. Read more on /basement-waterproofing/.

Related questions

Is a French drain the same as an interior perimeter drain? Not quite. A French drain usually means a buried gravel-and-pipe trench outside. Interior perimeter drainage runs inside along the footing and feeds a sump pump. Inside is the version we install because it lasts here. See /basement-waterproofing/.

Do I need a sump pump if I put in a drain? Almost always yes. The drain catches the water, the sump pump removes it. A drain with nowhere to send the water just relocates the puddle. Ours runs one half horsepower per 120 feet of drain.

Can I just use the floor drain my basement already has? Only if water reaches it on its own, which it rarely does. Existing floor drains sit mid-slab and miss the floor wall joint where leaks start. A perimeter system catches water at the source.

Will outside drainage be cheaper long term? No. Exterior excavation costs the most up front, and in our experience it tends to fail in two to three years as backfill settles. Interior drainage costs less and holds.