Masonry Waterproofing in Downers Grove, IL — Sealing Old Brick and New Veneer Differently

Downers Grove is unusual, and it makes waterproofing decisions unusually consequential.

Within a few miles you have genuine nineteenth-century brick — soft, porous, laid in lime mortar, on homes built when the village was a young rail suburb — and 1990s and 2000s brick veneer built to drain through a cavity. Those two walls manage water in opposite ways. Seal them the same and you'll damage one of them.

Masonry waterproofing in Downers Grove, IL starts with figuring out which one you own. Paul Lally's Masonry has been sealing Chicagoland brick since 1988, and we'll say the important part first: done right, over sound mortar, with a breathable product, it's excellent value. Done wrong, it destroys the wall.

What masonry waterproofing actually is

The application of a clear, penetrating sealer — typically a silane, siloxane, or blend — to brick, block, stone, and mortar. Not paint. Not a visible coating. It soaks into the pores, lines them so liquid water beads and runs off, and then disappears. The wall looks exactly as it did, just dry.

The property that matters is vapor permeability. Masonry always carries some moisture, and it has to be able to leave as vapor. A proper sealer blocks liquid water coming in while letting vapor pass out.

Silane, siloxane, and why one product doesn't fit every wall

• Silanes — smaller molecules, penetrate deeply; suited to denser, harder, less absorbent masonry.
• Siloxanes — larger molecules, perform well on porous, absorbent units, sitting nearer the surface.
• Blends — aim for useful behavior across a range of substrates.

Which belongs on your wall depends on how absorbent your brick actually is — something we assess on site. A product that performs beautifully on hard 1990s veneer can underperform on soft, thirsty Victorian brick, and vice versa.

Two Downers Grove walls, two different answers

The older stock — soft, porous, historic

The homes in and around the older sections near downtown and the Metra corridor: Victorians, four-squares, bungalows, Prairie-influenced houses. Soft locally-fired brick, lime-based mortar, limestone sills and trim.

These walls dry by breathing. They're meant to absorb some water and release it. The honest answer here is frequently that sealing isn't the fix — repointing with soft matched mortar, sorting the gutters, and fixing the grade will do far more. If sealing is warranted at all, it must be breathable, and it goes on only after the joints are sound.

A film-forming coating on this masonry is genuinely destructive. It traps moisture in soft, porous brick, and the next hard freeze pushes the face off.

The newer stock — brick veneer over frame

The large volume of homes from the 1970s through the 2000s: brick-veneer fronts and elevations over frame, with a drainage cavity, flashing, and weep holes behind the brick.

A veneer wall is designed to let water in and drain it back out. That changes everything. Leaks in veneer are frequently about blocked weep holes, failed flashing, or mortar droppings clogging the cavity — not the brick face. Sealing the face doesn't address any of that, and it can slow the wall's ability to dry. See brick veneer vs. solid masonry.

Never seal a veneer wall's weep holes. They're the drain.

The rule that governs everything: repair first, seal last

The overwhelming majority of water entering a brick wall comes through failed mortar joints — not through the face of the brick. A soft, receded, or cracked joint is an open channel. Sealer over that joint doesn't close it; it coats it, conceals it, and lets water keep running behind while the wall looks freshly maintained.

The order is not negotiable:

1. Fix the water paths — repoint failing joints, replace spalled brick, address the lintel, chimney crown, coping, and sealant at window heads.
2. Fix the drainage — gutters clear, downspouts discharging well away, grade sloping away.
3. Clean and let the masonry dry.
4. Then seal — if sealing is warranted at all.

If a contractor offers to seal a wall with visibly failing joints and never mentions repointing, that tells you what the rest of the work will be.

Signs sealing might help

• Efflorescence — white, chalky salt deposits on the brick
• Early spalling — faces beginning to flake, powder, or pop
• Damp or musty interior walls on an exterior-facing room
• Dark, slow-drying patches for days after rain
• Water stains near a chimney chase or above windows
• A chimney above the roofline never sealed — the most exposed masonry you own
• Heavily weather-exposed elevations, typically north and west
• A wall just repointed — sealing after tuckpointing protects the investment

How Paul Lally's Masonry waterproofs a Downers Grove home

1. Identify the wall type — solid historic masonry or veneer. Everything follows from this.
2. Inspect the whole system — joints, brick condition, sills, lintels, chimney, coping, weep holes, grade, gutters.
3. Tell you honestly whether sealing is right, and what must happen first. Sometimes the answer is that your wall doesn't need it.
4. Repoint and repair what's failing.
5. Assess brick absorbency to inform which sealer chemistry suits it.
6. Clean the masonry — efflorescence, dirt, biological growth, and old residue removed so the sealer can penetrate.
7. Let the wall dry. This step gets its own time.
8. Protect surroundings — windows, trim, landscaping, walks, drives.
9. Apply at the correct coverage rate, typically saturating wet-on-wet so the product goes into the masonry rather than sitting on it.
10. Cure, inspect, and walk the work with you, with a realistic re-seal interval.

Materials

Breathable, penetrating silane and siloxane-based sealers — clear, vapor-permeable, invisible once cured, matched to the porosity of your brick. Mortar for repointing matched for type, color, sand, and joint profile: soft lime-rich mixes on historic brick, standard Type N on most later work, Type S only where structure and exposure genuinely call for it.

Never a film-forming coating. Never masonry paint. Never sealer over joints we haven't made sound first.

What drives the cost

• Square footage and how many elevations
• Surface prep — cleaning, and whether efflorescence or biological growth has to come off
• Height and access — second-story elevations or a chimney above the roofline
• Repointing scope required before sealing
• Brick porosity — softer, thirstier brick absorbs more product
• Site conditions — mature landscaping, decks, tight side yards

Paul Lally's Masonry gives a free on-site estimate in writing, and we'll say plainly if sealing isn't what your wall needs.

Local context: DuPage County water

Downers Grove was settled in the 1830s and grew as a rail suburb, which is why its housing stock spans nearly two centuries within a compact area — and why a blanket approach to sealing does damage here.

What both populations share is DuPage County weather: repeated hard freeze-thaw cycling, wet springs, and heavy wind-driven rain from the west and northwest that pushes water at walls horizontally rather than letting it run down the face.

That's why the west and north elevations are almost always the first to show efflorescence and early spalling, and why chimneys — exposed on four sides above the roof — are the single most common thing we're asked to seal. It's also why the bottom courses near grade, taking snowpack, splashback, and de-icing salt, deteriorate faster than anything above them.

Related masonry services in Downers Grove

Waterproofing is the last step, not the first. Most projects here begin with tuckpointing and repointing, and often include brick repair, brick replacement, chimney repair and rebuilds, lintel repair and replacement, limestone and sill repair, caulking and joint sealant, and foundation masonry repair. For whole-house scopes, residential masonry restoration.

Worth reading: is masonry waterproofing worth it and do I need waterproofing after tuckpointing. Nearby: tuckpointing in Downers Grove, brick repair in Downers Grove, limestone and sill repair in Downers Grove, and masonry waterproofing in Naperville.

Find out whether your brick should be sealed at all

Paul Lally's Masonry Inc. is a family-owned, insured masonry contractor serving Chicago and the Chicagoland suburbs since 1988 — tuckpointing, brick repair and replacement, chimney repair and rebuilds, lintel replacement, masonry restoration, and waterproofing for residential and commercial properties. Built on Craftsmanship. Backed by Experience.

We'll identify what kind of wall you have, tell you what's actually letting water in, and recommend sealing only where it genuinely helps — in the right order. Our family name is on every job.

Free on-site estimates — call (708) 448-8866 or request an estimate online.