Crawl Space Foundation Repair: The Masonry Side

Crawl space foundation repair covers two different kinds of work. One is the masonry: the stone, block or brick walls and piers that hold the house up. The other is everything those walls carry or enclose: the wood framing, beams, posts, insulation, vapor barrier and air quality of the space. Knowing which part has failed tells you who to call.

In older homes north of Boston, crawl spaces often sit under additions, porches and sunrooms, with walls of fieldstone, rubble stone, block or brick. The masonry problems are usually the same ones basements have: mortar washing out, loose stones, cracks, a wall pushed in by soil pressure, and water getting through.

Gerrior Masonry & Landscape Construction Corp. of Woburn, MA repairs the masonry side of crawl space foundations and the outside drainage that keeps them dry. This guide explains what goes wrong, how those repairs work, and which jobs belong to other trades.

What goes wrong with crawl space foundations

• Failed mortar in stone walls. Old fieldstone and rubble walls lose mortar over decades. Joints open, sand collects at the base, and stones work loose.
• Cracks in block walls, especially stair-step cracks along the mortar joints.
• Walls pushed inward. Wet soil pressing on a short wall, and freezing in winter, can make it lean or bulge.
• Shallow footings under additions. Footings that were not set below frost depth can move with the freeze-thaw cycle every winter, which shows up as cracks and sticking doors in the rooms above.
• Water coming in through open joints and low spots, often because roof water or grading sends it toward that side of the house.
• Brick or block piers that have cracked, lost mortar or settled.

Signs to check for

• Sand, mortar crumbs or fallen stones along the inside base of the wall.
• Cracks you can see from outside, along the exposed foundation.
• Standing water or a wet floor in the crawl space after rain.
• A wall that is visibly out of line.
• Floors that slope or bounce, or doors and windows above the crawl space that stick. These can come from the framing as well as the foundation, so they are a reason to have both looked at.

How crawl space masonry is repaired

Repointing stone and block walls

When the stones or blocks are sound but the joints have failed, the old mortar is raked out and new mortar is packed deep into each joint. On old stone the mortar has to suit the wall: a mix much harder than the stone can trap moisture and cause new damage. Loose stones are reset as the work goes. Our stone foundation repair post walks through this in more detail.

Crack repair

Cracks in block and poured walls are cleaned and sealed. If the crack comes from a wall that is moving, sealing it is not enough. The cause has to be dealt with too.

Rebuilding a failed section

When part of a wall has bulged or collapsed, that section is taken down and rebuilt on a sound base. The house has to be supported while that happens, and the plan for that support is set before any stones come out. Where the cause is structural, a structural engineer should be part of the decision.

Keeping water away from the walls

Most crawl space water starts outside. Regrading so soil falls away from the wall, piping downspouts underground to a dry well, and adding a French drain on the uphill side all reduce the water that reaches the masonry. Any digging along a foundation starts with a Dig Safe notice so utility lines get marked. Dig Safe says Massachusetts law requires at least 72 hours' notice, not counting weekends and holidays.

What other trades handle

A lot of what is sold as crawl space repair is not masonry. These parts are often handled by other trades, so ask us whether they are part of your project:

• Sagging floors, rotted sill plates, beams and posts, and jacks or steel supports are carpentry and structural work. A structural engineer or framing contractor is the right first call.
• Encapsulation, vapor barriers, dehumidifiers and insulation are often done by crawl space and basement waterproofing companies.
• Mold is a job for a mold remediation contractor, and pests for a pest control company.

Often a crawl space needs more than one of these. The masonry and outside drainage should usually come first, since a dry, sound wall makes every other repair last longer.

Fixing foundation issues under an older home

Crawl spaces are tight. Access often means working on hands and knees through a small opening, and some repairs are easier to reach from outside by digging along the wall. That affects how the work is planned and what it costs. The foundation repair cost guide explains what decides the price without guessing at numbers.

If the same house has a full basement too, the problems are often connected. Our foundation leak repair guide covers how water gets through a foundation and how to read the cracks.

When to call a mason

Call when you see mortar or stones coming loose, a crack that is growing, a wall that is out of line, or water standing in the crawl space after rain. Our foundation and bulkhead repair page explains how we look at the wall and the drainage together. If the floors above are sagging, call a structural engineer as well; we are glad to work alongside their plan.

Common questions

Is crawl space foundation repair the same as basement foundation repair?

The masonry work is the same: repointing, crack repair and rebuilding sections. What differs is access, and the fact that crawl spaces add framing, moisture and insulation issues that other trades handle.

Can a stone crawl space wall be repaired instead of replaced?

Usually, yes. Most old stone walls need repointing and some reset stones. Only sections that have bulged or collapsed need rebuilding.

Do you install crawl space encapsulation or jacks?

Our crawl space work is the masonry and the outside drainage. Encapsulation is usually done by crawl space waterproofing companies, and jacks or beams by structural or framing contractors. We are glad to work alongside them.

Why is my crawl space wet after rain?

Usually because water is collecting against that wall outside: a downspout, soil sloping toward the house, or a low spot. Fixing that first is often the biggest improvement.

Gerrior Masonry & Landscape Construction Corp. is a family-owned masonry company in Woburn, in business for over 30 years. We are fully insured and our work is guaranteed. Call (781) 933-4157 or request a free estimate and we will look at the walls and the drainage together.