Why is my building leaking?

Water intrusion is one of the most common problems affecting San Francisco buildings.

Leaks may originate from:

• Roof systems

• Windows and doors

• Balconies and decks

• Stucco façades

• Exterior cladding

• Waterproofing failures

• Drainage systems

• Expansion joints

Water often travels long distances before becoming visible inside the building, making the source difficult to identify without a systematic investigation.

A qualified engineer can perform testing and inspections to determine:

• The source of the leak

• The extent of hidden damage

• Repair options

• Long-term waterproofing strategies

What is building envelope consulting?

The building envelope includes all exterior systems that separate the interior of the building from the environment.

These systems include:

• Roofs

• Exterior walls

• Windows

• Doors

• Waterproofing systems

• Sealants

• Stucco

• Cladding systems

Building envelope consultants investigate:

• Water intrusion

• Moisture problems

• Air infiltration

• Thermal performance

• Material deterioration

• Construction defects

The goal is to identify deficiencies and design repairs that improve durability and sustainability.

What causes stucco cracks?

Stucco cracks are common throughout the Bay Area and may result from:

• Building settlement

• Thermal movement

• Seismic activity

• Moisture intrusion

• Improper installation

• Structural movement

• Aging materials

Small hairline cracks are often cosmetic, but larger or recurring cracks may indicate:

• Hidden moisture problems

• Framing movement

• Structural distress

• Waterproofing failures

Engineers evaluate cracking patterns to determine whether repairs are cosmetic or structural in nature.

What causes window leaks?

Window leaks are commonly caused by:

• Failed sealants

• Improper flashing

• Frame movement

• Stucco cracks

• Waterproofing deficiencies

• Deteriorated gaskets

• Wind-driven rain

Water may enter:

• Around window frames

• At sill connections

• Through wall assemblies

• Through adjacent façade materials

Window water intrusion investigations often involve testing to determine precisely how and where water is entering the building.

What is window water intrusion testing?

Window water intrusion testing is a controlled investigation used to reproduce leaks under monitored conditions.

Testing may involve:

• Spray rack testing

• Chamber testing

• Controlled water application

• Moisture mapping

• Thermal imaging

• Interior inspections

The purpose is to:

• Identify the source of leakage

• Evaluate window performance

• Determine repair requirements

• Develop long-term waterproofing solutions

Testing helps avoid unnecessary repairs by focusing on the actual source of the problem.

Why are balconies deteriorating?

Balconies are among the most vulnerable components of a building because they are exposed to:

• Rain

• Sunlight

• Temperature fluctuations

• Moisture

• Seismic movement

• Occupant loading

Common balcony problems include:

• Dry rot

• Wood decay

• Corrosion

• Cracked coatings

• Waterproofing failures

• Structural deterioration

In California, balcony safety has become a major concern due to SB-721 and SB-326 inspection requirements.

What causes deck failures?

Deck failures are often caused by:

• Water intrusion

• Rotting wood framing

• Corrosion of fasteners

• Improper construction

• Lack of flashing

• Deferred maintenance

Because many exterior elevated elements contain concealed framing, deterioration may remain hidden until significant damage has occurred.

Regular inspections help identify problems before they become safety hazards.

What is SB-721 repair design?

When inspections identify deficiencies under SB-721, engineers prepare repair documents that may include:

• Structural drawings

• Waterproofing details

• Framing repairs

• Material specifications

• Permit documents

• Construction notes

The goal is to restore structural safety and extend the service life of the exterior elevated element.

Repair designs must address both:

• Visible damage

• The underlying causes of deterioration

What causes retaining wall failures?

Retaining walls in San Francisco are exposed to:

• Soil pressure

• Groundwater

• Earthquakes

• Differential settlement

• Corrosion

• Drainage failures

Common warning signs include:

• Cracks

• Leaning walls

• Bulging

• Separation

• Drainage issues

• Movement

Retaining wall failures can threaten:

• Buildings

• Sidewalks

• Roads

• Neighboring properties

Early engineering evaluations can identify problems before catastrophic failures occur.

What causes hillside movement?

Hillside properties throughout San Francisco are susceptible to:

• Soil creep

• Landslides

• Water infiltration

• Seismic movement

• Erosion

• Retaining wall failures

Warning signs include:

• Cracks in foundations

• Tilting retaining walls

• Uneven floors

• Separating sidewalks

• Sloping floors

• Expanding cracks

Geotechnical and structural engineers often work together to investigate hillside movement and develop stabilization strategies.

What is waterproofing?

Waterproofing refers to systems designed to prevent water from entering the building.

Examples include:

• Deck membranes

• Balcony coatings

• Roof systems

• Window flashings

• Sealants

• Below-grade waterproofing

• Expansion joints

Effective waterproofing:

• Prevents leaks

• Protects structural components

• Reduces maintenance costs

• Extends service life

Many structural problems begin as waterproofing failures.

What causes façade deterioration?

Exterior façades are exposed to:

• Rain

• Sunlight

• Wind

• Moisture

• Pollution

• Earthquakes

Common façade problems include:

• Stucco cracking

• Water intrusion

• Corrosion

• Material delamination

• Sealant failures

• Structural movement

Regular façade inspections help owners identify problems early and plan repairs proactively.

What is concrete spalling?

Concrete spalling occurs when pieces of concrete crack, loosen, or separate from the surface.

Common causes include:

• Corrosion of reinforcing steel

• Water intrusion

• Freeze-thaw cycles

• Carbonation

• Poor drainage

Spalling is frequently observed on:

• Balconies

• Parking structures

• Concrete façades

• Retaining walls

• Walkways

Although it may begin as a cosmetic issue, spalling can eventually affect structural integrity.

What is corrosion mapping?

Corrosion mapping is an engineering investigation used to determine:

• Where corrosion is occurring

• The severity of deterioration

• Repair priorities

• Future maintenance needs

Corrosion mapping is commonly used on:

• Reinforced concrete balconies

• Parking garages

• Waterfront structures

• Retaining walls

• Concrete façades

The results help engineers develop targeted repair strategies.

How do engineers investigate structural damage?

Structural investigations may include:

• Visual inspections

• Crack mapping

• Material testing

• Moisture measurements

• Structural analysis

• Destructive testing

• Non-destructive testing

• Drone inspections

The objective is to determine:

• The cause of damage

• Whether the damage is ongoing

• Repair requirements

• Long-term performance expectations

What is a repair specification?

A repair specification is a technical document that describes:

• Materials

• Construction methods

• Repair procedures

• Quality control requirements

• Testing requirements

• Contractor qualifications

Specifications help ensure:

• Consistent bids

• Higher construction quality

• Better long-term performance

Detailed specifications reduce uncertainty and improve project outcomes.

What is an Engineer of Record?

The Engineer of Record is responsible for:

• Preparing repair drawings

• Developing specifications

• Coordinating permits

• Reviewing contractor submittals

• Responding to field questions

• Observing construction

• Assisting with final approvals

The Engineer of Record helps ensure repairs are completed in accordance with the approved design.

How do contractors bid projects?

The engineer prepares:

• Repair drawings

• Technical specifications

• Bid documents

• Construction requirements

Qualified contractors submit proposals based on the same information.

Competitive bidding helps:

• Improve pricing transparency

• Compare contractors fairly

• Reduce misunderstandings

• Improve project quality

What is construction oversight?

Construction oversight includes:

• Site observations

• Progress meetings

• Shop drawing reviews

• Quality assurance

• Contractor coordination

• Testing reviews

• Change order evaluations

Construction oversight helps protect the owner's investment and improve the quality of repairs.

Why choose RAS Engineering for restoration projects?

RAS Engineering provides building restoration and forensic engineering services throughout San Francisco and the Bay Area.

Our services include:

• Building envelope consulting

• Window water intrusion testing

• Stucco failure investigations

• SB-721 repair design

• Retaining wall inspections

• Hillside investigations

• Waterproofing design

• Structural investigations

• Repair specifications

• Engineer of Record services

• Construction oversight

• Failure investigations

We help property owners, HOAs, apartment owners, and commercial building owners understand their buildings, identify problems early, and develop practical repair solutions that improve safety, durability, and long-term performance.

Schedule a Building Restoration Consultation

If your San Francisco property is experiencing leaks, structural deterioration, façade distress, balcony problems, or retaining wall concerns, RAS Engineering can help.

Our team provides engineering services designed to protect your property, preserve its value, and create long-lasting solutions for the unique challenges facing Bay Area buildings.