Why are there holes in my basement wall?

Most holes in a basement wall come from one of a few places. Weep holes a contractor drilled to let trapped water out, pipe or service penetrations from when the house was built, anchor holes left by old form ties on a poured wall, or open mortar joints on a block or fieldstone wall. A few are harmless. Some are a water path you want sealed and drained. If water shows up at those holes, the real fix is interior drainage, not just plugging the hole.

Here is how to tell which kind you have, and what to do about it.

The kinds of holes, and what each one means

Weep holes. Small holes drilled near the bottom of the wall, usually in a line. Somebody put them there on purpose. On a block wall the hollow cores fill with water, and weep holes let it drain out at the floor instead of building pressure inside the block. A weep hole is a relief valve someone built in on purpose. The catch is the water still lands on your floor unless a drain catches it.

Form-tie holes. On a poured wall you may see small round holes in a grid. Those are from the metal ties that held the forms when the wall was poured. The builder patches them, and years later a patch can pop and weep in a hard rain.

Pipe and service penetrations. Where a water line, conduit, or the radon pipe comes through the wall, there is a hole around it. If that seal cracks, water and soil gas sneak in.

Open mortar joints. On block or fieldstone walls the mortar can crumble out over time and leave gaps. Same story on the floor wall joint, the seam where the wall meets the slab.

Why water finds those holes in the first place

The hole is only half of it. The other half is the water pushing on the wall.

Most homes sit on disturbed backfill, the looser soil the builder dug out and put back when the foundation went in. It drains slowly and holds water. After a hard rain or a spring thaw, water pools against your foundation, leans on the wall, and goes after every hole, crack, and joint it can find. NH frost heave makes it worse all winter. So a hole that stayed dry for years can start weeping.

What actually fixes it

Caulking a hole feels like the answer. It usually is not. Plug one spot and the water shifts to the next weak point. Without addressing the water, the problem does not get better. It gets worse.

For real water coming in at the wall, the durable fix is to catch it on the inside. That is our Forever Dry System, a basement job: a full perimeter interior drain, a sump pump at one 1/2 hp per 120 feet of drain, a 12-mil wall vapor barrier, and a dehumidifier. The drain sits at the floor wall joint, takes whatever comes through the wall or those holes, and carries it to the sump, which pumps it out. With that system we 100% guarantee you stay dry or we come back free of charge! Basement waterproofing runs $3,000 to $30,000, and the price tracks the length of wall we drain and the prep needed first.

If those holes are bone dry and the wall is sound, you may not need a system yet. A dry weep hole is doing its job. A single weeping crack on an otherwise dry wall is a crack injection, not a full system. When a full system is out of budget, fill the crack and don’t look back. Crack injection runs $1,000 to $3,000, with a 10-year warranty.

We do not dig up your yard to waterproof from outside. In our field experience those exterior jobs tend to fail in a couple of years and cost more. The fix that lasts is interior drainage. If a hole is around your radon pipe, that gets sealed as part of a radon system. Radon mitigation runs $900 to $6,000, and most homes land around $1,950 to $2,250 and a test is $50, credited toward the job if you move ahead.

The Forever Dry System carries a full transferable lifetime warranty, with the sump covered 3 years and the dehumidifier 5. Trusted by 5,000+ homeowners in New England, Google 4.9 across 250 reviews, BBB A+ accredited, licensed and insured.

Talk to us

Call us at 603-610-1770 or book your free inspection. We will look at every hole, tell you which ones matter and which ones don’t, and send a written quote within 24 hours.

More on the parts of the job: basement waterproofing, structural and foundation repair, foundation repair, radon mitigation, and the 603 guarantee. If the holes are in a crawl space, start with crawl space services. EPA covers radon at epa.gov/radon and the DOE has building basics at basc.pnnl.gov.

Related questions

Are weep holes in a basement wall a problem? Not on their own. A weep hole is a relief valve a contractor drilled to let water out of a hollow block wall so pressure does not build up. The catch is the water still lands on your floor. A perimeter drain at the floor wall joint catches it, so the wall can weep without wetting your basement.

Should I seal the holes in my basement wall? Seal the ones around pipes and the radon line, yes. But do not just caulk holes that are letting water in and call it done. Plug one and the water shifts to the next weak spot. For real seepage the durable fix is interior drainage. We sort out which holes need sealing and which need a drain when we are down there.

My basement wall has holes and gets wet. What does waterproofing cost? Basement waterproofing runs $3,000 to $30,000 in New Hampshire. The number tracks how much wall we drain and the prep the basement needs. A single weeping crack on a dry wall is smaller, a crack injection at $1,000 to $3,000. You get the exact number after the free inspection, in writing within 24 hours.