Brick Retaining Walls, Chimneys and Masonry Repair in Northbrook, IL

Brick Retaining Walls in Northbrook

We build and repair masonry retaining walls in Northbrook. Masonry retaining walls come in two kinds, and they hold back soil differently. A mortared brick or reinforced block wall is rigid: its footing resists overturning and sliding, and it should sit on firm undisturbed soil or compacted fill below the frost line, which Northbrook’s code sets at 42 inches. A segmental block wall is flexible: it does not need a frost-depth footing where the soil can bear it, but it needs a leveling pad of gravel or unreinforced concrete at least 6 inches thick and backfill compacted in thin lifts. Brick for a retaining wall should be Grade SW, laid in Type M or S mortar with full joints, and used brick only if testing shows it meets Grade SW, because most used brick does not. Either way, water works against a wall: the block industry warns that it can increase the loads on a wall, erode the soil around it and weaken the ground it stands on. For segmental walls, its guidance is at least 12 inches of clean gravel behind the units, a drain pipe of at least 4 inches running to daylight or a drainage system at a slope of 1 percent or more, and the ground graded to carry water away at the top and the bottom. For mortared walls, its guidance is a drain along the back where heavy rain is expected, a waterproofed back face where the backfill is relatively impermeable, and a cap on top to keep water out. That matters here: the stormwater district classes most of Northbrook’s soils as cohesive or highly cohesive clays that let very little water soak in, on ground that averages about a 1.5 percent slope. We also build and repair brick patios and walks, and handle concrete work, chimney repair, tuckpointing and masonry waterproofing.

Why Retaining Walls Lean, Bulge and Crack

An outward lean is a serious warning sign that a wall may be heading toward collapse, and many collapses have followed heavy rain. Bulging, cracks along the top of the wall and soil swelling up at its base are the other signs, and efflorescence on the face shows water moving through the masonry; in a wall against earth, the Brick Industry Association notes, the salts can come from the soil behind it. Northbrook knows heavy rain: the West Fork of the North Branch of the Chicago River reached its record crest of 10.1 feet on August 14, 1987, and the stormwater district’s study of Northbrook and Northfield Township counts 1,007 structures flooded by overwhelmed local drainage in a 100-year storm, against 141 from the rivers. Some walls need an engineer from the start: under the residential code, a wall that is not supported at the top and holds back more than 48 inches of unbalanced fill, or a wall more than 24 inches tall that resists lateral loads in addition to the soil, has to be designed to accepted engineering practice, and the block industry says segmental walls should be designed by a qualified engineer when they carry surcharge or live loads or sit on poor foundation soils.

Chimney Repair and Brickwork on Northbrook’s 1960s and 1970s Houses

Most Northbrook houses were built after the war, so the masonry questions are chimneys, veneer and lintels more than century-old brick. A chimney should have a sloped crown with a drip edge and a bond break at the flue, a lined flue, and base flashing at least 4 inches up where it meets the roof. Brick veneer drains through flashing and weep holes at the base and over windows, and steel lintels over openings can rust, and rust can take up to ten times the space of the steel, cracking the brick above. Winters add stress to wet masonry: NOAA readings at O’Hare average 74 days a winter that cross freezing, in a range of 47 to 91 (winters 2015-16 to 2024-25). Where cracks are wider than about 0.075 inch, run through several bricks, step or run diagonally, or where brick has moved out of plane, the Brick Industry Association says the damage generally warrants investigation by a professional engineer to find the cause and recommend the repair. When joints need repointing, we match the mortar to the existing wall on evidence, as in our historic mortar and stone matching work.

Serving Northbrook as Part of the Chicago Area

North Shore Masonry serves Northbrook from our Chicago operation, with work nearby in Highland Park, Northfield, Wilmette, Skokie, Prospect Heights, Des Plaines and Mount Prospect. Start at our Chicago masonry services hub for every service and town we cover.

Talk to a Masonry Contractor About Your Northbrook Project

If you have a retaining wall that is leaning or bulging, a patio or walk that has settled, a cracked chimney crown or open mortar joints, call us at +1 847-864-5990 or request a free on-site estimate. Retaining wall work, and installing or replacing a patio, walk or driveway, brick pavers included, needs a Village permit; chimney rebuilds and structural masonry may too, and we confirm permit needs with Development and Planning Services before work starts. We will tell you what needs attention now and what can wait, and where a wall is past the code’s engineering thresholds or shows signs of movement, we will recommend a professional engineer’s design or assessment before any work starts.

Retaining Wall, Brick Paver and Chimney FAQs for Northbrook, IL

Do I need a permit for a retaining wall in Northbrook?

Yes. The Village lists retaining walls, along with grade changes and drainage work, as Site Work that needs a permit, and its list does not give a height below which a wall is exempt. The application includes a plat of survey and a site plan and cross-section showing the wall’s size, its distance to the property line and its height above grade at the lowest grade. Grade or drainage changes need an engineering site plan approved by the Village Engineer, and the Village will not permit work that would unreasonably divert runoff onto neighboring property. We confirm the requirements with Development and Planning Services (847-664-4050) before work starts.

When does a retaining wall need an engineer?

Under the residential code Northbrook has adopted, a wall that is not supported at the top and holds back more than 48 inches of unbalanced fill, or a wall more than 24 inches tall that resists lateral loads in addition to the soil, has to be designed to accepted engineering practice. For segmental block walls, the block industry adds walls that carry a surcharge such as a driveway or a slope above, walls under live loads, walls on poor foundation soils, and walls past the heights at which the block maker’s own design information calls for an engineer. Those are minimums, not a promise that a smaller wall needs no engineering, so we confirm what the Village will require for your wall with Development and Planning Services before work starts.

Why is my retaining wall leaning or bulging?

Often because of water. Water that cannot drain out from behind a wall adds load to it, which is why the block industry calls for clean gravel behind a segmental wall, a drain pipe to daylight or a drainage system, and the ground graded to carry water away at the top and the bottom. An outward lean is a serious warning sign that a wall may be heading toward collapse, and many failures have followed heavy rain. Bulging, cracks along the top and soil pushing up at the base are the other signs. Adding mortar to the face of a dry-laid stone wall can make it worse by blocking its drainage. If a wall is leaning, have it looked at promptly rather than waiting for the next heavy rain.

What brick pavers hold up to Northbrook winters?

Class SX, the severe-weathering class: the Brick Industry Association says Class NX pavers should not be used where they are subject to freezing and that deicing salts can damage Class NX and MX pavers. It calls for a slope of at least 2 percent to shed water, an edge restraint with a vertical face to keep the pavers in place, and an extra 4 inches of base on clay soils, more where frost heave is a risk. In Northbrook, installing or replacing a driveway, patio, walk or stoop needs a Village permit, brick pavers included.

Do chimney repairs need a permit in Northbrook?

The Village’s permit list does not name tuckpointing, chimney or veneer work either way. Chimney rebuilds and structural masonry may need a Village permit, and smaller jobs such as crowns, repointing and relining are not listed either, so we confirm permit needs with Development and Planning Services (847-664-4050) before any chimney work starts. One rule to know: when a furnace is replaced and vents into a masonry chimney, the Village requires the flue to be re-sized as needed, which typically means a liner.

What mortar should be used for tuckpointing or repointing brick?

A mortar softer and more vapor permeable than the brick, and no stronger than the original, matched to the existing wall in color and joint profile. The Brick Industry Association points to Type N, O or K depending on the original, and the National Park Service describes mortar as the sacrificial part of the wall: it should wear before the brick does.