Masonry Waterproofing NYC

Masonry waterproofing in NYC for brick and mortar walls that let water into your home or building. We find exactly where the water is getting in, repair the masonry that’s letting it through, and protect the wall with breathable materials that won’t trap moisture inside.

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What Masonry Waterproofing Really Means

Masonry waterproofing is the work of stopping water from passing through a brick or stone wall into the building behind it. Brick is porous and was never meant to be completely watertight. Older walls handle rain by absorbing some of it and letting it dry out again, so real waterproofing means repairing the places where water gets in faster than the wall can dry.

That’s why a coat of sealer is rarely the answer on its own. In NYC, leaks through masonry almost always trace back to something specific, such as open mortar joints, cracked or spalled brick, a failed flashing at a window sill or lintel, or coping that lets water into the top of the wall. Fix those, and most leaks stop. Paint over them with a heavy coating, and the water gets trapped inside the brick, where it causes the spalling and damage that brought you here in the first place.

Stopping Leaks Through Brick Walls in NYC

Water inside a wall rarely shows up where it came in. A stain on a third-floor ceiling can start at a parapet, and a damp patch by a window can start at an open joint several feet above it. We treat every masonry leak as a problem to trace, not a spot to patch, so the repair lands where the water actually enters.

Finding the Entry Point

Close inspection and controlled water testing to pin down exactly where the wall is letting water through.

Repairing the Masonry

Open joints repointed, damaged brick replaced, and failed flashings at sills, lintels, and coping restored.

Breathable Protection

Where a wall needs it after repairs, a penetrating water repellent that lets the brick dry instead of sealing moisture in.

Clues That Water Is Getting Through Your Walls

Masonry leaks can take a long time to show inside, and by the time a stain appears, water has usually been moving through the wall for a while.

These clues, inside and out, point to water getting through the brick rather than coming from the roof or plumbing.

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Damp or Stained Exterior Walls Inside

Marks on the inside face of an outside wall.

White Powder on the Brick

Salt deposits left behind as water moves through the masonry.

Leaks Only in Windy Storms

Water that shows up only when rain is driven sideways.

Peeling Paint or Bubbling Plaster

Finishes lifting on walls that face the weather.

Leaks Below Window Sills

Water appearing under windows after heavy rain.

Musty Rooms Along Exterior Walls

Persistent damp smells in rooms with outside brick walls.

How We Track Down and Stop Masonry Leaks

Leak work goes wrong when the fix comes before the diagnosis. Ours always starts with finding the source.

01

Inside & Outside Survey

We map the damage inside and inspect the wall outside, from the base to the coping.

02

Controlled Water Testing

Sections of wall are tested one at a time to confirm where water is getting in.

03

Masonry Repairs

Joints, brick, and flashings at the entry points are repaired properly.

04

Recheck & Protect

Repaired areas are checked, and a breathable repellent is applied only where it helps.

NYC Rules to Know Before Waterproofing Masonry

A leak isn’t just a maintenance problem in New York City. Depending on the building, it can also be a legal one.

Leaks in Rental Buildings

In buildings with three or more apartments, NYC's Local Law 55 requires owners to fix the underlying causes of mold, and leaks through the walls are a common one.

Landmarked Facades

On landmarked buildings and in historic districts, coatings and repellents change how a facade looks and weathers, so they generally need LPC review.

FISP Buildings

On buildings over six stories, water getting into the masonry is often behind the conditions listed in FISP reports.

Masonry Waterproofing Cost in NYC Depends on the Source

Because every leak has a different cause, the price follows what the testing finds, not a flat rate per wall.

Number of Entry Points

One open joint versus problems spread across the wall.

Type of Repair

Repointing, brick replacement, or flashing work at sills and lintels.

Wall Height & Access

Ground-floor walls versus upper floors needing staging.

Testing & Protection

Water testing, and whether a repellent is needed after repairs.

Why Owners Call Us When Other Leak Fixes Failed

Many of the walls we work on have already been caulked, painted, or sealed by someone else, and they’re still leaking. The difference is where we start.

Source Before Solution

No repairs until we know where the water enters.

Breathable Materials Only

Nothing that traps water inside the brick.

Repairs, Not Just Coatings

The masonry is fixed first, every time.

Honest About the Source

We tell you if the leak is coming from somewhere other than the wall.

(+1) 917-355-8556

What Owners Say About Our Masonry Leak Repairs

4.6 /5

“We kept getting moisture through one exterior masonry wall during heavy rain. The problem areas were repaired first and the waterproofing work was completed very neatly.”

Frank M. Owner

“Our brick wall had cracks and weak mortar joints where water was getting in. The team addressed those areas properly before applying the waterproofing treatment.”

Adam K. Owner

“We wanted to protect the exterior masonry before another winter caused more damage. The crew explained the vulnerable areas clearly and completed the work without changing the appearance of the brick.”

Sean R. Owner