How to pump water out of the basement

To pump water out of a basement, set a submersible pump (or a wet/dry shop vac for shallow water) at the lowest spot, run the discharge hose outside to ground that slopes away from the house, and keep going until the floor is clear. That clears today’s flood. It does not stop the next one. The lasting fix is a sump pump set in a pit fed by perimeter drainage, which catches water under the slab and pumps it out before it ever reaches your floor.

So here is the order. Safety first. If the water is anywhere near outlets, the panel, or the furnace, cut the power to that area before you step in. Standing water plus electricity is dangerous. When in doubt, call an electrician or your utility.

Power sorted? Now you pump.

For a few inches of water, a wet/dry vacuum works fine. For a flooded floor, you want a submersible utility pump. Set it at the lowest point. Most basements pitch toward the middle or toward an old drain. Run the hose out a window or a bulkhead, and aim it well away from the foundation. If you dump it right next to the wall, it soaks back in and you pump the same gallons twice. Push it 10 feet or more from the house, downhill.

When the water gets too low for the pump to grab, switch back to the shop vac for the last bit. Then mop. Then run fans and a dehumidifier hard for a few days so the slab and framing dry out.

That is the cleanup. Here is why it happened.

Water pools at your foundation because the soil right against the house is disturbed backfill. It is the loose dirt that got put back when the house was built, and it drains slower and holds more water than the packed ground around it. Add a heavy rain or spring melt, and that wet soil pushes against the wall. Water finds the weakest seam, usually the floor wall joint where the slab meets the wall, and seeps in. Up here, NH frost heave makes it worse by shoving the walls inward over the winters.

A utility pump on the floor treats the symptom. A sump system treats the cause.

That is what our Forever Dry System does. We cut a channel around the inside perimeter of the basement, lay drain pipe that carries water to a pit, and set a sump pump in that pit (1/2 hp per 120 feet of drain). We add a 12-mil vapor barrier on the walls and a dehumidifier so the room stays dry, not just unflooded. The water gets collected and pumped out before it can ever pool on your floor. Basement waterproofing with the Forever Dry System runs $3,000 to $30,000, and what drives that number is mostly the length of wall we have to drain and how many pumps the layout needs.

You probably do not need all of that yet if this was a one-time event from a freak storm or a failed pump. Sometimes the fix is a new pump and a check valve. We will tell you that when we look. We would rather right-size it than sell you a full system you do not need.

One thing we do not do is dig up the outside and seal the foundation from the exterior. In our experience that fix fails in two or three years once the soil settles back. Interior drainage lasts. That is why our basement waterproofing is built from the inside.

What about a power outage? A sump pump is useless when the grid drops, which is often exactly when the storm hits. So we add a battery backup. A charged backup battery can pump roughly a residential pool’s worth of water, around 15,000 to 20,000 gallons, which buys you through most outages.

If your basement floods often, check your homeowners policy too. Standard policies usually do not cover groundwater or surface flooding, so know what you have before the next storm (see the Insurance Information Institute, iii.org).

The Forever Dry System is 100% guaranteed to be dry for life, and the guarantee is transferable. See the 603 guarantee for the details.

Related questions

Will a sump pump alone keep my basement dry? A sump pump helps, but it only works if water can reach the pit. Without perimeter drainage feeding it, water can still come in at the floor wall joint and never make it to the pump. We pair the pump with full perimeter drainage in our basement waterproofing so every drop gets collected.

Should I waterproof from outside instead? We do not recommend exterior excavation waterproofing. In our field experience it fails in two or three years as the backfill settles. We fix basements from the inside with interior drainage, which holds up long term.

What if I have a crawl space, not a basement? A wet crawl space needs crawlspace encapsulation, not the Forever Dry System. That means a 12-mil wall and 20-mil floor vapor barrier, dimpled drainage matting, a dehumidifier, and a sump. Different problem, different fix.

Can a flooded basement cause foundation problems? It can. Constant water pressure and frost heave push on walls and can crack them. If you see bowing or cracking, that is a job for structural and foundation repair, not just drainage.

Got water now and want it gone for good? Call us at 603-610-1770 or book your free inspection. We will look at your basement, tell you what it actually needs, and give you a quote within 24 hours.