Beautiful homes. Better questions.

Love the home.
Ask how
it dries.

Brick outside. Wood behind it. A rooftop deck above it. What happens when moisture gets into the places you can’t see?

A buyer’s guide to Chicago masonry homes with concealed wood roof and floor assemblies.

Ask these before you buyUnderstand the moisture issue
Illustrative Chicago brick residential buildings with flat roofs
Chicago architecture, illustrated.
Exterior appearance alone cannot establish moisture condition.
Water gets in.
The real question is: can it get out?

Rain, indoor humidity and cold surfaces interact inside a building. Drainage, air control and drying potential determine what happens next.

Why this matters in Chicago

One building.
Several systems. A shared moisture problem.

Chicago’s cold winters and humid summers challenge building assemblies in different ways. Masonry can absorb rain. Wood needs conditions that let it dry. Insulation, roofing and indoor humidity all influence that balance.

01

Masonry can hold water.

Rain-wetted brick and concrete block can store moisture. Flashing, drainage and drying paths help keep that moisture away from vulnerable materials.

02

Warm air meets cold materials.

In winter, indoor air leaking into a roof or wall cavity carries moisture to cold materials. Condensation forms when that air contacts a surface at or below its dew point. Hidden wood can become wet without a visible roof leak.

03

Less drying can change the balance.

Interior insulation can make masonry colder and reduce inward drying. The result depends on the assembly, rain exposure and control of air and water.

These are established moisture mechanisms—not a diagnosis of every masonry home. See the building-science references below.

Know what you’re looking at

A closer look starts with the assembly.

Pay particular attention to masonry homes built, rebuilt or substantially renovated since the 1990s when wood roofs, insulation, air sealing and roof decks may have changed the building’s moisture behavior.

The year is a screening cue, not a scientific cutoff. Older buildings and other assemblies can also merit review.

  • Brick or concrete-block walls with wood roof trusses or joists
  • Flat or low-slope roofs, parapets and rooftop decks
  • Wood members bearing on or extending into masonry
  • Insulation against masonry or within concealed roof cavities
  • Recurring staining, musty odors or elevated indoor humidity
  • Roof, HVAC or insulation changes with limited assembly documentation

These features help guide questions. They do not, by themselves, establish a defect or damage.

Before the offer. Before the closing.

Five questions worth asking.

Bring these to your inspector, seller and real estate team. When an answer depends on concealed conditions, ask what additional evaluation would help.

“If moisture gets into this roof or wall, where does it drain—and how does the wood dry?”

What is the roof-and-wall assembly?

Ask for drawings, roof replacement records, insulation details and photos taken before cavities were closed.

Where does water drain?

Review parapets, flashings, roof penetrations and transitions. A watertight roof surface is only part of the picture.

What keeps indoor air out of cold cavities?

Ask about the air barrier, roof ventilation strategy and humidity control, particularly after renovation.

Has concealed moisture been evaluated?

Find out what was measured, where, when and by whom. A dry accessible surface does not establish the condition of every concealed member.

What would a targeted review involve?

Clarify scope, cost, access and permission for any openings. Have your attorney address inspection timing and contract options.

A collaborative approach

Good professionals.
Difficult-to-see conditions.
Predictable moisture mechanisms.

A routine inspection may have limited access to concealed roof cavities and wood-to-masonry connections. A targeted building-envelope review can complement the work of your inspector, attorney, architect and contractor.

Sellers may be unaware of concealed moisture, too. Understanding the assembly helps everyone ask better questions, document findings and choose a practical next step.

Common questions

What this means for your home.

Does this mean every brick home has a problem?

No. Performance depends on the actual assembly, exposure, workmanship, maintenance and indoor conditions. The purpose of screening is to identify where more information could be useful.

Is spray foam the problem?

No single material explains every moisture condition. Foam type, location, thickness and installation matter alongside roof design, air leakage, masonry wetting and drying paths. Adding or removing insulation without understanding the assembly can miss the underlying issue.

Can a home look fine and still have concealed moisture?

Yes. Paint, drywall and finished ceilings can hide parts of the assembly. Visible conditions are useful clues, but a targeted evaluation may require measurements or agreed access to concealed areas.

Can these buildings be helped before major damage occurs?

Often, earlier investigation offers more options. A plan may address water entry, air leakage, humidity and drying. If damaged structural wood is suspected, a qualified structural professional should evaluate it.

Start with a conversation

Understand the building.
Then choose the next step.

Tom Decker · Chicago Green Insulation

Buying, owning or preparing to sell a Chicago masonry home? Share the property’s construction, renovation history and what you’re seeing. Ask about a targeted moisture consultation and the appropriate review scope.

This page provides general education. Property-specific conclusions require evaluation; structural findings require qualified structural review.

Request a consultation

Send to tomd6431+condensation@gmail.com. The button opens your email app with your request ready to send.

Read the building science

The mechanisms behind the questions.

These references explain assembly risks and moisture control. They do not estimate the share of Chicago homes with damage.

Building Science Corporation · Interior Insulation Retrofits of Load-Bearing Masonry Walls in Cold ClimatesBuilding America report · Internal Insulation of Masonry Walls: Final Measure GuidelineBuilding Science Corporation · Building Profile: New — Chicago