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Pittsburgh Foundation Repair Co.

Serving Pittsburgh and nearby areas

Crumbling Stone Foundation in Pittsburgh, PA

Mortar turning to sand and stones coming loose are signs your stone foundation needs repair, and a free inspection shows how far it has gone and what it will take to fix.

Call now: (412) 990-2570 or book your free inspection online

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Tell us what you are seeing. A local specialist calls you back the same business day.

Local to Pittsburgh

We connect property owners in Pittsburgh and nearby areas, including Mount Washington, Polish Hill, Spring Hill, Lincoln Place, Bon Air and Lawrenceville, with one independent local foundation repair specialist.

What it costs

Typical published ranges for Pittsburgh. The contractor's written estimate is the price, and the inspection is free.

WorkTypical range
Inspection and written estimate Free
Repointing masonry $3 to $15per square foot
Interior drain $40 to $120per linear foot
Sump pump, installed $600 to $2,500
Basement waterproofing, whole job $3,000 to $7,500
Structural engineer visit $250 to $500

See typical foundation repair prices in Pittsburgh

Many older Pittsburgh homes stand on walls of stacked stone held together with lime mortar. These walls were built long before poured concrete was common, and many still do their job. But the mortar between the stones slowly turns back to sand. When enough of it is gone, water pours in, stones loosen and the wall can start to lean.

What you will notice

Sand on the basement floor

It collects along the base of the wall, especially after wet weeks.

Mortar you can scrape out by hand

Or with a key, sometimes inches deep.

Loose or missing stones,

Or gaps you can see light or feel air through.

Water seeping through the joints,

Not just at one crack.

White crust or powder

On the stones where water dries.

Old cement patches peeling off

In sheets.

A wall that leans in or bulges,

Often on the uphill side of the house.

Musty air and mold

On wood that touches the wall.

Why stone foundations crumble in Pittsburgh

They are old. About half of the homes in the city were built before 1940. Sandstone from the region was used for bridge piers, streets and buildings around Pittsburgh. One of the oldest houses in the city, a 1792 farmhouse in Hazelwood, is built of random-cut sandstone.

Water does the damage. Old foundations were laid without a footing drain or an outside coating. Rain soaks the soil, and water moves through the joints. As it does, it slowly washes the lime out of the mortar. Pittsburgh had its wettest year on record in 2018, and wet years speed this up.

Freeze and thaw. The Pittsburgh History and Landmarks Foundation points to freeze and thaw, which opens cracks as water gets in and freezes. That is hard on mortar near the top of the wall, where the ground freezes.

The wrong patch. Many stone walls were covered or patched with hard cement over the years. The National Park Service warns that mortar harder than the masonry can damage it. Cement over a wet wall can also trap water and make the old mortar behind it break down faster.

Uphill pressure. On a hillside lot, soil on the high side pushes on the wall. Once the mortar is weak, that side may start to bulge.

When it is minor and when it is urgent

Usually minor: a little sand at the base of the wall, shallow joints that need work, and some dampness in wet weather. Plan for repointing and better drainage.

Call soon:

  • Mortar is gone deep into the joints in large areas.
  • Stones wiggle or have fallen out.
  • Water comes through after most rains.
  • The wall has a bulge or lean you did not notice before.

Urgent: a section of wall has fallen in, stones are falling out of a wall that is bulging, or the floor joists above have pulled off the top of the wall. Keep people out of the basement and call (412) 990-2570.

How stone foundations usually get fixed

Repointing

Loose mortar is raked out, often about two inches deep, and new mortar is packed in. Engineers often suggest testing a sample of the old mortar so the new mix matches. The work goes in short sections, because pulling out too much at once can loosen big stones.

Rebuilding a section

Where stones have fallen or a corner has failed, that part of the wall is taken down and relaid.

Interior drain and sump pump

Water that comes through the wall is caught at the floor edge and pumped out. This is the most common way to dry a stone basement.

Outside drainage

Gutters, downspout lines and grading that slopes away from the house cut the water at the source.

Bracing

A wall that leans or bulges may need steel braces or anchors, or a rebuilt section, before it is repointed.

What it costs

These are typical ranges from published cost guides, not quotes. Stone work varies a lot with how deep the joints are and how much of the wall needs it.

What to do before the inspection

  1. Sweep the floor along the wall and see how much sand builds up in a week.
  2. Photograph loose stones, deep joints and wet spots, with a ruler for scale.
  3. Check from one end of the wall for a bulge or lean.
  4. Fix gutters and downspouts so roof water goes away from the house.
  5. Do not coat the wall with paint or cement before the visit.

Then call (412) 990-2570 or send the short form to book a free inspection of your stone foundation.

Frequently asked questions

Is a stone foundation bad?

No. Many stone foundations in Pittsburgh have held up houses for more than 100 years. They do need care. The mortar wears out long before the stone does, and it has to be replaced from time to time.

Why is there sand on my basement floor?

Old lime mortar breaks down when water moves through it. It falls out of the joints as sand. A little sand is normal wear. Piles of it, or joints you can poke deep into, mean the wall needs work.

Can I parge or cement over my stone walls?

A coat of cement on a damp stone wall often traps water behind it. The coat can crack and fall off, and the mortar behind keeps crumbling. Fix the water first, then repoint with the right mortar.

What kind of mortar should be used on an old stone foundation?

One that is softer than the stone and close to the old mix. Engineers often suggest testing a sample of the old mortar first. Hard modern cement mortar can damage old masonry.

Can I repoint the stone wall myself?

Some owners do small areas. Pros warn that a stone wall done wrong can be damaged for the long term, and pulling out too much at once can loosen big stones. Work in short sections or have a crew do it.

Will a stone basement ever be dry?

It can be much drier. Most stone basements in Pittsburgh get an interior drain and a sump pump, plus better gutters and grading. Expect less water, not a sealed, finished-room basement in every case.

Other services

Common foundation repair problems in Pittsburgh

Areas we serve around Pittsburgh

(412) 990-2570 Free inspection