DIY Chimney Waterproofing in Englewood: What You Can Safely Do vs. When to Call a Pro for Older Brick Chimneys

By Steven P Chimney LLC Team · Updated November 9, 2026

For Englewood’s older brick chimneys, DIY waterproofing like sealing minor cracks with silicone caulk or applying a waterproofing sealant to the crown can work, but only if the masonry is structurally sound. If you see crumbling mortar, rust stains on the liner, or water stains inside the flue, call a licensed chimney sweep immediately. Englewood’s freeze-thaw cycles and high humidity make leaks worse fast, so don’t wait until winter to address them.

What is chimney waterproofing, and why does it matter more in Englewood?

Chimney waterproofing is the process of sealing your chimney’s masonry and crown (the top layer) to prevent water from seeping in. In Englewood, where older brick homes with traditional masonry chimneys are common, this is critical because our climate, hot, dry summers followed by rapid freeze-thaw cycles in winter, accelerates wear. Water seeps into cracks, freezes, expands, and cracks the mortar or bricks further. Over time, this leads to rusted liners, weakened masonry, and even structural damage. The Chimney Safety Institute of America the Chimney Safety Institute of America (CSIA)|https://www.csia.org/)) notes that unsealed chimneys lose 80% of their lifespan to water damage, and Englewood’s brick chimneys, built decades ago, are especially vulnerable. If your chimney has a cracked crown or deteriorating mortar joints, waterproofing isn’t just about leaks, it’s about preserving the integrity of your home’s oldest (and often most historic) feature.

Can I waterproof my Englewood chimney myself? The 3 DIY fixes that work, and 3 that don’t

Yes, you can handle some waterproofing tasks yourself, but only if your chimney’s masonry is in decent shape. Here’s what you can safely DIY for an Englewood brick chimney: 1. Sealing minor cracks in the crown: Use a high-quality silicone or polyurethane sealant rated for masonry (like RedGard or SikaFlex). Scrub the mortar joint clean using a stiff wire brush, then spread the sealant into the gap and level it with a trowel. This works for hairline cracks less than 1/8 inch wide. 2. Applying a waterproofing sealant: Products like ChimneySaver or DryLok create a breathable barrier that repels water but allows moisture to escape. Brush or spray this onto the crown and upper masonry. Follow the manufacturer’s instructions. Englewood’s dry summers can make sealants dry too fast if you don’t apply them in the right conditions. 3. Replacing a damaged chimney cap: If your cap is rusted or missing, a stainless steel cap (not aluminum) is a straightforward DIY project. Just ensure it fits snugly over the flue and has a tight seal.

What you cannot DIY: - Repointing crumbling mortar: If your chimney’s mortar joints are powdery or missing, this requires a masonry pro. DIY repointing often fails because Englewood’s freeze-thaw cycles demand specific mortar mixes and techniques. - Fixing a cracked flue liner: If water is leaking into your home through the liner, you need a professional to inspect for rust, corrosion, or misaligned sections. A chimney sweep in Englewood can assess whether the liner needs relining or sealing. - Waterproofing a chimney with active leaks: If you see water stains inside the flue or damp spots on the ceiling near the fireplace, the damage is already severe. Call a pro to diagnose the source, it could be a failed crown, deteriorated flashing, or even a cracked liner.

Pro tip: If your chimney is over 30 years old (common in Englewood’s historic neighborhoods like the Cherry Creek North area), assume there’s hidden damage. A quick visual check isn’t enough, schedule a chimney inspection before attempting any DIY fixes.

How do I know if my Englewood chimney’s waterproofing needs a pro? 4 warning signs you’re ignoring

Englewood homeowners often miss subtle signs that their chimney’s waterproofing has failed until it’s too late. Here’s what to watch for: 1. Rust stains on the liner or smoke chamber: This means water is pooling inside the flue, likely from a cracked crown or failed sealant. Rust accelerates in Englewood’s humid summers, so don’t wait until winter to act. 2. Damp or discolored ceiling/wall near the fireplace: Water leaking from the chimney often stains drywall or plaster before you notice the chimney itself. If you see this, the crown or flashing is compromised. 3. Crumbling mortar joints: If the mortar between bricks looks like sand or powder, it’s failed. Englewood’s freeze-thaw cycles make this worse. DIY repointing won’t last. A licensed chimney sweep can assess whether the entire chimney needs repointing or if a waterproofing overlay will suffice. 4. Moss or algae growth on the chimney: This isn’t just cosmetic. Moss traps moisture, which seeps into the masonry and weakens the bricks over time. A professional can apply a breathable waterproofing sealant that prevents regrowth.

If you see any of these, skip the DIY fixes and call a chimney sweep in Englewood. The cost of a professional waterproofing job ($300–$800, depending on the chimney’s height and condition) is far cheaper than repairing water-damaged drywall, replacing a rusted liner ($1,500–$3,500), or even rebuilding part of the chimney. See our pricing guide for a breakdown of common chimney repair costs in Englewood.

What’s the difference between waterproofing and repointing? Why Englewood’s older brick chimneys need both

Waterproofing and repointing serve different purposes, and in Englewood’s older brick homes, you often need both. Here’s how they differ: - Waterproofing focuses on sealing the surface of the chimney (crown, upper masonry) to repel water. This is what DIY sealants handle, but it only works if the underlying masonry is intact. - Repointing replaces the mortar joints between bricks. In Englewood, where many homes date back to the early 1900s, the original mortar (often lime-based) has degraded. Repointing with modern, freeze-thaw-resistant mortar is a must, but it’s labor-intensive and requires a pro.

The problem? Waterproofing alone won’t fix crumbling mortar, and repointing won’t stop water from seeping through cracks in the crown. A chimney sweep in Englewood will inspect both issues and recommend a solution. For example: - If your chimney has minor cracks but solid mortar, a waterproofing sealant might suffice. - If the mortar is failing but the crown is intact, repointing plus a sealant is the best approach. - If both are failing, you may need a full chimney restoration, including a new crown and relined flue.

Englewood’s historic districts, like those near South Broadway, often have chimneys built with softer, less durable bricks. These require more frequent maintenance. Learn more about masonry repairs for older homes to avoid costly surprises.

When should I waterproof my chimney in Englewood? The best time, and why waiting is risky

The ideal time to waterproof your chimney is late summer or early fall, before Englewood’s first heavy rains and freeze-thaw cycles. Here’s why timing matters: - Summer humidity: Englewood’s dry summers can make sealants dry too quickly if applied in extreme heat. Aim for temperatures between 50°F and 75°F for the best adhesion. - Fall prep: Waterproofing before winter gives the sealant time to cure fully before snow and ice test your chimney’s defenses. The National Fire Protection Association the National Fire Protection Association (NFPA)|https://www.nfpa.org/)) recommends inspecting and maintaining chimneys before the heating season begins. - Avoid spring: If you waterproof in spring, the sealant may not have time to cure before summer storms hit, reducing its effectiveness.

Pro tip: If your chimney has a stainless steel liner (common in homes built after the 1980s), waterproofing is even more critical. Steel liners rust when exposed to moisture, and Englewood’s high humidity accelerates this process. A chimney sweep can check for rust spots during an inspection, see our guide on liner health for signs to watch for.

Never skip waterproofing if you’ve recently had chimney work done. For example, if you replaced a chimney cap or relined the flue, the new materials are especially vulnerable to water damage until properly sealed.

What’s the cost of DIY vs. pro chimney waterproofing in Englewood? A realistic breakdown

Here’s what you can expect to spend in Englewood, where labor costs and material quality vary based on the chimney’s age and condition: | Task | DIY Cost | Pro Cost | When to DIY | When to Call a Pro | |-------------------------|--------------------|-----------------------|------------------------------------------|--------------------------------------------| | Sealant for crown | $20–$50 | Included in inspection | Minor cracks, intact mortar | Large cracks, crumbling mortar | | Waterproofing sealant | $50–$150 | $300–$600 | Cosmetic leaks, no structural damage | Active leaks, rusted liner, failed cap | | Chimney cap replacement | $100–$300 | $200–$500 | Simple cap, no liner issues | Rust, misalignment, or liner damage | | Repointing mortar | N/A | $800–$2,500 | Never (requires pro skill) | Crumbling joints, water stains inside flue |

Why the gap? DIY products are cheap, but pros use commercial-grade sealants and tools designed for Englewood’s climate. For example, a $50 DIY sealant might last a year in dry conditions, but a $500 pro-grade application with a breathable membrane can last 10+ years. Also, pros can spot hidden issues, like a cracked liner, that DIYers miss.

If you’re unsure, start with a free estimate from a licensed chimney sweep. Many offer inspections that include waterproofing assessments, so you’re not paying for guesswork. See our areas served to find a local expert familiar with Englewood’s older brick chimneys.

What happens if I ignore waterproofing in an Englewood home? The hidden costs of skipping it

Ignoring waterproofing in Englewood’s climate leads to a domino effect of damage, each step costing more to fix. Here’s what you’re risking: 1. Rusted flue liner: Water seeps into the liner, causing rust that weakens the structure. A rusted liner can collapse, forcing a full reline job ($1,500–$3,500). Englewood’s older homes often have clay liners, which are especially prone to moisture damage. 2. Masonry erosion: Bricks absorb water, freeze, and crack. This isn’t just cosmetic, it compromises the chimney’s stability. In extreme cases, you’ll need partial or full chimney reconstruction ($5,000–$15,000). 3. Fire hazards: Damp creosote (the tar-like buildup from wood burning) ignites more easily. The EPA’s Burn Wise program the EPA's Burn Wise program warns that wet creosote is a leading cause of chimney fires in older homes. 4. Indoor water damage: Leaks behind the chimney can rot framing, damage insulation, and even lead to mold. Repairing water-damaged drywall and replacing rotten wood can cost $1,000+.

Englewood’s historic neighborhoods, like those near South Platte Park, have homes with chimneys built in the 1920s–1950s. These were constructed with less durable materials and no modern waterproofing standards. If your chimney is over 50 years old, assume it’s at higher risk. Our guide on older home chimney maintenance details how to spot early warning signs before they become emergencies.

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