Why can't I just use regular concrete sealer on my historic brick?

Historic solid masonry walls rely on being able to 'breathe'—moisture that enters must be able to evaporate out. Film-forming sealers trap moisture inside the wall, which then causes the brick to spall (face layers pop off) when the trapped water freezes, heats, or reacts with salts. Always use breathable, penetrating treatments on historic masonry.

My brick home was built in 1920. What mortar should I use for repairs?

Pre-1930s homes typically have lime mortar, which is softer than the brick. You must use lime-based mortar (Type O or softer) for repairs. Using modern portland cement mortar will be harder than the brick, causing moisture to be trapped in the brick rather than escaping through the joints. This leads to brick spalling and accelerated deterioration.

How do I know if I have rising damp vs. rain penetration?

Rising damp creates a 'tide mark' of damage that's consistent around the building's perimeter, typically up to about 3 feet high. It's worse in winter when evaporation is slower. Rain penetration shows up on specific walls (usually weather-facing), follows irregular patterns, and appears after rain events. A moisture survey can definitively diagnose the source.

Can I power wash my historic brick to clean it?

Pressure washing is generally not recommended for historic masonry. High pressure erodes soft mortar and can drive water deep into the wall. Instead, use gentle methods: soft brushing, low-pressure water rinse, or specialized masonry cleaning chemicals designed for historic materials. The gentlest effective method is always preferred.

How often should historic masonry waterproofing be renewed?

Penetrating water repellents typically last 5-10 years on Florida's exposed masonry, with south and west elevations degrading faster. Lime washes need renewal every 3-7 years. Repointing, when done correctly with lime mortar, can last 50+ years. Annual inspection helps catch problems early before they require major intervention.

Should I waterproof the inside or outside of my historic foundation?

For historic foundations, exterior waterproofing is preferred when accessible—it stops water before it enters the wall. However, excavation may not be feasible or appropriate for some historic properties. Interior approaches like drainage systems and breathable coatings can manage symptoms, but addressing exterior grading, drainage, and below-grade moisture is the long-term solution.

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Waterproofing Historic Masonry

Protecting Tampa Bay's historic brick and masonry homes from moisture damage while preserving their character and architectural integrity.

Schedule Assessment (813) 420-7561

Historic Masonry Types in Tampa Bay

Different masonry types require different waterproofing approaches. Understanding your home's construction is the first step.

Solid Brick (Pre-1930s)

Characteristics:

Multiple wythes of brick, lime mortar, no cavity

Waterproofing Approach:

Breathable treatments only; avoid film-forming sealers

Common Issues:

Soft mortar erosion, rising damp, efflorescence

Tampa Examples: Hyde Park bungalows, Ybor City historic buildings

Brick Veneer (1930s-1970s)

Characteristics:

Single wythe over frame or block, air cavity, portland mortar

Waterproofing Approach:

Cavity drainage, weep holes, flashing repair

Common Issues:

Weep hole blockage, flashing failure, tie corrosion

Tampa Examples: Seminole Heights, mid-century ranch homes

Historic Stucco

Characteristics:

Lime-based original stucco over masonry or lath

Waterproofing Approach:

Lime wash or breathable coatings; match original system

Common Issues:

Cracking, delamination, incompatible repairs

Tampa Examples: Mediterranean Revival homes, Davis Islands

Coral Rock/Coquina

Characteristics:

Porous natural stone, common in older Florida buildings

Waterproofing Approach:

Consolidants and breathable water repellents

Common Issues:

Severe erosion, biological growth, salt damage

Tampa Examples: Historic waterfront structures, some Ybor buildings

Waterproofing Methods for Historic Masonry

Appropriate treatments that protect against moisture while maintaining historic integrity.

Breathable Water Repellents (Silane/Siloxane)

Penetrating treatments that repel liquid water while allowing vapor transmission

Best For: Most historic masonry; maintains breathability critical for old walls

Lifespan:5-10 years

Cost:$2-5 per SF

Considerations:

Must test compatibility; some products darken masonry

Lime Wash / Mineral Coatings

Traditional lime-based coatings that are fully vapor-permeable

Best For: Historic stucco, soft brick, where original appearance is priority

Lifespan:3-7 years

Cost:$3-8 per SF

Considerations:

Historically accurate; requires periodic renewal

Injection Damp Proofing

Chemical injection to create a barrier against rising damp

Best For: Rising damp in solid masonry walls

Lifespan:20+ years

Cost:$50-100 per linear foot

Considerations:

Invasive; requires drilling; may not be appropriate for all historic buildings

Drainage Plane Installation

Adding or repairing the drainage cavity behind veneer

Best For: Brick veneer buildings with cavity drainage failures

Lifespan:30+ years

Cost:$15-40 per SF (invasive)

Considerations:

Major intervention; requires removing exterior finish

Repointing with Lime Mortar

Replacing deteriorated mortar with compatible lime-based mortar

Best For: Pre-1930s masonry with eroded joints

Lifespan:50+ years when done correctly

Cost:$10-25 per SF

Considerations:

Critical to match original mortar; portland cement damages soft brick

Common Mistakes to Avoid

Well-intentioned repairs can cause more harm than good. Here's what NOT to do with historic masonry.

Using Portland Cement Mortar on Historic Brick

Hard mortar damages soft brick; moisture trapped; spalling and cracking

Correct Approach:

Use lime-based mortar softer than the masonry units

Applying Film-Forming Sealers

Traps moisture inside wall; accelerates deterioration; peeling

Correct Approach:

Use only breathable, penetrating water repellents

Pressure Washing Historic Masonry

Drives water deep into wall; erodes soft mortar and brick

Correct Approach:

Use gentle cleaning methods; low-pressure rinse only

Ignoring Interior Moisture Sources

Exterior treatment fails because moisture comes from inside

Correct Approach:

Address interior humidity, plumbing leaks, and vapor drive

Painting Over Moisture Problems

Paint traps moisture; blisters and peels; underlying damage continues

Correct Approach:

Solve moisture problem first; use breathable mineral paints if painting

Florida-Specific Challenges

Tampa Bay's climate creates unique challenges for historic masonry that require specialized solutions.

High Humidity Year-Round

Constant moisture stress on masonry; condensation on cool surfaces

Solution:

Maintain interior humidity below 60%; ensure adequate ventilation

Wind-Driven Rain

Horizontal rain penetrates joints and cracks; hurricane pressure differentials

Solution:

Quality repointing; breathable water repellent on exposed elevations

Salt Air (Coastal)

Salt crystallization damages masonry; accelerates corrosion of ties

Solution:

Regular gentle washing; desalination treatment for severe cases

Intense UV Exposure

Accelerates coating degradation; thermal cycling stresses mortar joints

Solution:

UV-stable treatments; consider shading from landscaping

High Water Table / Flooding

Rising damp; flood damage; salt contamination from floodwater

Solution:

Below-grade waterproofing; drainage systems; damp proof courses

Masonry Condition Assessment

What to look for when evaluating your historic masonry's condition.

Inspection Item	What to Look For	Recommended Action
Mortar Joint Condition	Erosion depth, cracking, missing mortar, previous repair quality	Repoint with lime mortar where erosion exceeds 1/4 inch
Efflorescence	White salt deposits on masonry surface	Identify and eliminate moisture source; dry brush to remove
Spalling / Face Loss	Brick faces flaking off; pieces missing from masonry	Determine cause (usually moisture); consider consolidant or replacement
Cracks	Structural vs. surface cracks; active vs. dormant	Structural cracks require engineer evaluation; surface cracks may need filling
Biological Growth	Algae, moss, lichen, plant growth in joints	Gentle removal; treat underlying moisture; consider biocide
Previous Repairs	Incompatible materials; failed patches; coating buildup	May need to remove previous repairs before proper restoration

Frequently Asked Questions

Protect Your Historic Home from Moisture Damage

FCS understands the unique challenges of waterproofing historic masonry in Florida's climate. We use appropriate methods that protect your home while preserving its historic character.

Schedule Assessment Call (813) 420-7561

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Waterproofing Historic Masonry

Historic Masonry Types in Tampa Bay

Solid Brick (Pre-1930s)

Brick Veneer (1930s-1970s)

Historic Stucco

Coral Rock/Coquina

Waterproofing Methods for Historic Masonry

Breathable Water Repellents (Silane/Siloxane)

Lime Wash / Mineral Coatings

Injection Damp Proofing

Drainage Plane Installation

Repointing with Lime Mortar

Common Mistakes to Avoid

Using Portland Cement Mortar on Historic Brick

Applying Film-Forming Sealers

Pressure Washing Historic Masonry

Ignoring Interior Moisture Sources

Painting Over Moisture Problems

Florida-Specific Challenges

High Humidity Year-Round

Wind-Driven Rain

Salt Air (Coastal)

Intense UV Exposure

High Water Table / Flooding

Masonry Condition Assessment

Frequently Asked Questions

Related Historic Restoration Resources

Hyde Park Renovation Guide

Historic Restoration Services

Exterior Waterproofing

Protect Your Historic Home from Moisture Damage

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