Foundation Crack Repair in Lancaster, PA

Foundation crack repair is the work of sealing a crack that lets water through a poured concrete or concrete block wall. It is for Lancaster homeowners who see a crack weeping, staining or leaving a damp streak down the wall after rain.

How a leaking foundation crack gets fixed

Concrete cracks. It shrinks as it cures, the soil under and beside it moves, and water in the ground freezes and thaws against it. Many cracks are harmless and stay dry. The ones that matter are those that go all the way through the wall, because groundwater pressing on the outside then has a direct path into your basement.

A leaking crack is sealed by filling it from the inside with a liquid that flows into the full depth of the gap and then sets. The filler bonds to both faces of the crack, so water has nowhere to travel. This is one of the less invasive jobs under basement waterproofing, because it needs no digging and usually no cutting of the floor.

Sealing only works when we know why the crack opened. A hairline shrinkage crack in a stable wall is a simple repair. A crack that keeps widening is telling you something about the soil or the footing, and we will say so before we seal anything.

Types of foundation cracks and what each one means

The direction and shape of a crack tell us a lot about its cause. We look at this before choosing a repair.

Vertical cracks in poured walls

A straight or slightly angled crack running from the top of the wall toward the floor is the most common kind. It is usually a shrinkage crack from when the concrete cured, or a minor settlement crack. These are the best candidates for injection, and they often leak only in heavy rain.

Horizontal cracks

A crack running sideways along the wall, often near the middle, usually means soil pressure is pushing the wall inward. Sealing it stops the water but does not stop the movement. If the wall is bowing or the crack is stepping out of line, we will recommend an engineer's opinion and likely a structural repair first.

Stair-step cracks in block walls

In concrete block, cracks tend to follow the mortar joints in a stepped pattern. Water travels through the joints and down the hollow cores of the block. A single joint can be repointed or injected, but a long run of stepped cracks points to settlement or pressure that needs a closer look.

Floor and cove joint cracks

Where the floor slab meets the wall there is a joint that often seeps when the water table rises. Cracks in the slab itself can leak the same way. These are sealed differently from wall cracks, and water here is often a sign that drainage along the footing needs attention.

Epoxy and polyurethane crack injection

Most leaking cracks are repaired by injection. The two materials do different jobs, and choosing between them is a matter of whether the crack is wet, and whether the wall needs strength restored.

Polyurethane injection for active leaks

Polyurethane is a flexible resin that reacts with water. It expands as it meets moisture, fills the crack and cures into a watertight foam or gel. Because it stays slightly flexible, it keeps sealing if the wall moves a little with the seasons. It is our usual choice for a crack that is wet or running.

Epoxy injection for dry, stable cracks

Epoxy is rigid and strong. It bonds the two sides of a crack back together and can restore much of the wall's strength across that line. It needs a dry crack to bond well, so it suits a stable crack that is not leaking at the time of the visit. Because it does not flex, a crack that keeps moving can reopen beside the repair.

Hydraulic cement and surface patches

Hydraulic cement sets fast, even against flowing water, and is useful to stop a leak long enough to work. On its own, a surface patch rarely lasts, since water pressure behind it pushes the patch off the wall. We use it as a stopgap or as a cap over an injection, not as the repair.

How a crack injection visit goes, step by step

Most single-crack repairs are done in one visit. The steps are the same whichever resin is used.

• We clear the area and inspect the full length of the crack, inside the wall and along the floor.
• The crack is cleaned with a wire brush and the surface is dried where we can.
• Small injection ports are fixed along the crack at regular spacing.
• The crack face between the ports is sealed with a surface paste so the resin cannot run out.
• Resin is pumped in port by port, starting at the lowest, until it shows at the next port up.
• Once the resin cures, the ports are removed and the surface is ground flush.

When sealing the crack is not enough

Sealing one crack stops water at that spot. If the water is also arriving at the cove joint, through block cores or from several cracks at once, the crack was only one symptom. In that case the better fix is a drain along the footing with a pump, so water is collected and removed instead of chased from crack to crack. Wet basement repair covers that wider diagnosis.

If your basement already floods when it rains, a pump may be part of the answer. We can look at sump pump installation if the crack is one of several entry points.

Roof water matters here too. Downspouts that empty beside the wall and soil that slopes toward the house load the foundation with extra water, and that is often what opens or reopens a crack. Fixing those can protect the repair.

Foundation cracks in Lancaster homes

Lancaster sits in the Piedmont and gets about 42 inches of precipitation a year, with September the wettest month. Soil beside a foundation can stay saturated for long stretches, and that pressure finds every crack. Winters add freeze and thaw, which pries at small cracks and widens them season after season.

Lancaster was settled in the 1720s, and many neighbourhoods around the city, such as the West End, the Historic East Side and Chestnut Hill, have older homes. Some of these stand on stone or old block foundations with mortar joints that have worn away over time. Those walls leak differently from a poured wall, and a crack injection does not apply to rubble stone. We will tell you what your wall is made of and what repair fits it.

Newer homes in the surrounding area usually have poured concrete walls, where a single vertical crack is the usual complaint and injection is typically the right repair.