Older brick chimneys on Mercer Island often need more than just a sweep. The top upgrades—relining, capping, and crown sealing—address age-related wear, moisture intrusion, and fire hazards specific to our climate and housing stock. Investing in these now prevents costly repairs and keeps your fireplace safe and efficient for decades.
Why Mercer Island’s older brick chimneys need upgrades more than new ones
Mercer Island’s housing stock includes many pre-1980s brick chimneys, built before modern building codes and materials. These chimneys were often constructed with lime mortar that erodes faster in our damp, marine-influenced climate, leading to cracked flues, deteriorating crowns, and missing or damaged caps. Unlike newer chimneys, older masonry absorbs moisture, which freezes and thaws, spalling bricks and accelerating deterioration. The Chimney Safety Institute of America (CSIA) notes that older chimneys are also more likely to have undersized or unlined flues, increasing creosote buildup and fire risk. If your home is on Mercer Island’s East or West side, where homes are closer to Lake Washington or Mercer Slough, moisture exposure is even higher. Upgrading isn’t just about safety—it’s about preserving the historic character and structural integrity of your home’s masonry. Learn more about our inspections for older homes
A chimney inspection is the first step before any Mercer Island upgrade
A chimney inspection is a thorough assessment of your chimney’s condition, identifying cracks, creosote buildup, water damage, and structural weaknesses. For Mercer Island homeowners, this step is critical because older chimneys often hide problems beneath the surface. The National Fire Protection Association (NFPA) recommends a Level 2 inspection for chimneys in homes older than 20 years or after a chimney fire, property transfer, or major storm. On Mercer Island, where many homes are over 50 years old, a Level 2 inspection often reveals hidden damage from past earthquakes or moisture intrusion. We use cameras and moisture meters to detect issues in the flue and masonry that aren’t visible from the ground. Skipping this step risks installing upgrades on a compromised foundation, which could void warranties or fail inspections. Schedule your inspection today
Upgrade #1: Install a stainless steel chimney liner for safety and efficiency
A chimney liner is a protective layer inside your flue that improves draft, reduces creosote buildup, and prevents heat transfer to combustible materials. For Mercer Island’s older brick chimneys, a stainless steel liner is the gold standard. It’s corrosion-resistant, flexible enough to navigate tight bends, and compatible with both wood and gas appliances. The Chimney Safety Institute of America (CSIA) recommends relining chimneys with damaged or unlined flues to meet modern safety standards. In Mercer Island, where many homes have converted from wood to gas fireplaces, a liner ensures proper venting and prevents carbon monoxide leaks. Costs range from $1,200 to $3,500, depending on flue length and condition. We often pair this upgrade with a new chimney cap to prevent debris and animals from entering the flue. See our relining services
Upgrade #2: Replace your chimney cap to block Mercer Island’s rain and pests
A chimney cap is a small but mighty upgrade that keeps rain, snow, leaves, and animals out of your flue. Mercer Island’s wet winters and proximity to Lake Washington make a high-quality cap essential. Without one, water pools in the flue, accelerating brick erosion and mortar decay. Animals like raccoons and squirrels often nest in unprotected chimneys, creating fire hazards and blockages. The best caps are made of stainless steel with a mesh screen to block embers and debris. We recommend replacing caps every 10–15 years, especially on older chimneys where the original cap may be corroded or missing. Costs range from $200 to $600, depending on size and material. A properly installed cap also improves draft and reduces downdrafts, which are common in Mercer Island’s windy areas like the island’s north end. Get a free estimate for a new cap
Upgrade #3: Seal your chimney crown to stop water damage in its tracks
A chimney crown is the concrete or mortar slab that sits atop your chimney, shielding it from rain and snow. In Mercer Island, where freeze-thaw cycles are common, a cracked or deteriorating crown allows water to seep into the masonry, causing bricks to spall and mortar to erode. Unlike a chimney cap, which protects the flue opening, the crown shields the entire top of the chimney. We recommend resealing or rebuilding the crown every 10–15 years, especially for older chimneys with original mortar crowns. A modern crown is made of a flexible, waterproof material that expands and contracts with temperature changes. Costs range from $500 to $1,500, depending on the size and condition of the chimney. Skipping this upgrade risks costly water damage to your home’s interior and structural masonry. Learn how to spot crown damage
When to repair vs. replace your Mercer Island chimney’s masonry
Not all chimney damage requires a full replacement. For Mercer Island homeowners, repairing cracked bricks, repointing mortar, or rebuilding a damaged crown can extend your chimney’s life by decades. However, if more than 50% of the bricks are spalled, the flue is severely cracked, or the chimney is leaning, replacement may be the safer choice. We use a moisture meter to assess the extent of water damage and a camera to inspect the flue’s condition. For chimneys on older Mercer Island homes, especially those built before 1950, we often recommend a combination of repairs and upgrades to ensure longevity. Compare repair vs. replacement options
How Mercer Island’s climate affects your chimney upgrade timeline
Mercer Island’s climate—mild, wet winters and dry summers—accelerates wear on older chimneys. Moisture is the biggest enemy, causing bricks to crack and mortar to erode. The U.S. Environmental Protection Agency notes that chimneys in marine climates like Mercer Island’s need more frequent maintenance to prevent water damage. We recommend scheduling upgrades in late summer or early fall, before the rainy season begins, to ensure your chimney is ready for winter. For homeowners in neighborhoods like North Mercer or East Mercer, where homes are closer to the lake, we often recommend additional waterproofing treatments to protect the masonry. Plan your upgrade with our seasonal guide
What to expect during and after your Mercer Island chimney upgrade
Upgrading your chimney is a multi-step process that typically takes 1–3 days, depending on the scope of work. We start with a Level 2 inspection to assess the chimney’s condition, then proceed with relining, crown sealing, or cap replacement as needed. For relining, we use a stainless steel system that’s inserted into the flue and sealed in place. For crown repairs, we remove the old mortar, rebuild the crown with a waterproof material, and seal it to prevent future water intrusion. After the upgrade, we perform a final inspection and provide a warranty for our work. Most homeowners notice improved draft and reduced creosote buildup immediately. Get a free estimate for your upgrade
| Upgrade | Typical Cost | Lifespan | Best For |
|---|---|---|---|
| Stainless Steel Liner | $1,200–$3,500 | 20–30 years | Older chimneys, unlined flues, gas conversions |
| Chimney Cap (Stainless Steel) | $200–$600 | 10–15 years | All chimneys, especially older or damaged caps |
| Chimney Crown Sealing/Rebuild | $500–$1,500 | 10–15 years | Cracked or deteriorating crowns, water damage |
| Mortar Repointing | $300–$1,200 | 15–25 years | Loose or missing mortar joints, spalled bricks |
Frequently Asked Questions
My Mercer Island brick chimney is 60 years old and has never been relined. Is it too late to install a stainless steel liner?
It’s never too late to install a stainless steel liner. In fact, older chimneys benefit the most from relining because they’re more prone to creosote buildup and heat transfer to combustible materials. We’ve relined chimneys in Mercer Island homes built in the 1920s with no issues. The key is a thorough inspection first to ensure the flue is structurally sound.
Why does my Mercer Island chimney crown keep cracking every few years?
Mercer Island’s freeze-thaw cycles are hard on chimney crowns. Original mortar crowns aren’t designed to handle constant moisture and temperature changes. We recommend resealing with a flexible, waterproof material that expands and contracts with the weather. If your crown is cracked, it’s allowing water into the masonry, which will eventually cause bricks to spall.
Can I install a chimney cap myself, or should I hire a pro for my Mercer Island home?
While DIY chimney cap installation is possible, it’s risky on Mercer Island’s older brick chimneys. A poorly installed cap can leave gaps that allow water and animals in, or worse, damage the flue liner. We recommend hiring a professional to ensure a secure, watertight fit. Plus, we can inspect the chimney for hidden damage while we’re up there.
How much should I budget for a full chimney upgrade in Mercer Island?
For a full upgrade—relining, crown sealing, and cap replacement—budget between $2,500 and $6,000, depending on the chimney’s size and condition. Relining is the most expensive part, followed by crown repairs. We offer free estimates and can work with you to prioritize upgrades based on your budget and needs.