Why Seasons Matter
Temperature and moisture affect concrete and soil in predictable ways.
Temperature and Concrete
Concrete expands when warm and contracts when cold. Not by much. Maybe an eighth of an inch over a long wall between summer and winter. But that tiny movement concentrates at cracks. Cracks open wider in cold and close in heat.
This is why my January crack measurement was higher than my July measurement. The concrete had contracted, pulling the crack open slightly. Normal physics, not structural failure.
Soil Moisture Cycles
Wet soil pushes harder against walls. Dry soil shrinks and pulls away. In spring when the ground is saturated, hydrostatic pressure peaks. In late summer after a dry spell, soil shrinks away from the foundation.
My friend Dave in Texas deals with extreme versions of this. His expansive clay swells dramatically in wet weather and cracks in dry. His seasonal variation is much more pronounced than mine.
Freeze-Thaw
Water in concrete pores expands when it freezes. Repeated freeze-thaw cycles degrade concrete over time. This is why exterior concrete shows more weathering than protected basement walls. But even basement walls can suffer if they're wet going into winter.
Plant Activity
Tree roots are most active in spring and summer, pulling water from soil. A large tree near a foundation can cause seasonal soil movement as roots take up and release moisture. Gary's neighbor's willow tree was worst in summer when it was drinking the most.
My Spring Routine
April is my first inspection of the year, after everything thaws.
Post-Winter Damage Check
First thing I look for: any damage from winter. Did the freeze-thaw cycles cause new spalling on exterior concrete? Any new cracks that appeared over winter? My foundation has weathered 45 winters, but each year could bring new damage.
So far, no new winter damage in my five years of monitoring. But I check anyway.
Snowmelt and Water
Spring is when water pressure is highest. Snow melting plus spring rain equals saturated soil. I check for any new water entry, staining, or moisture. This is when my basement would be wettest if something were wrong.
Before I fixed my grading, I had water coming in every spring at the northeast corner. Now it stays dry. But I still check that corner first, every April.
Crack Measurements
I take my spring measurements knowing they might show slightly narrower cracks than winter. Concrete has started warming, cracks closing a bit. I compare to last April, not to January. Season to season is the valid comparison.
Drainage Assessment
I watch where water goes during a spring rain. Does it flow away from the house? Any puddles forming against the foundation? Spring is when drainage problems become obvious. The ground is saturated and every low spot holds water.
Summer Monitoring
Easier access, different concerns.
Minimum Crack Widths
Summer is when my cracks are at their seasonal narrowest. The concrete is warmest, most expanded. Cracks are tightest. This is a good time to establish how narrow a crack gets at its best. If even the summer minimum looks bad, that's more concerning than a winter maximum.
Soil Shrinkage Watch
Extended dry periods cause soil to shrink. I've seen gaps open between soil and foundation in hot, dry summers. Not a crisis, but worth noting. Extreme shrinkage could cause settlement. Dave in Texas actually waters around his foundation during droughts to prevent clay shrinkage.
Tree Root Effects
Trees are drinking hardest in summer. If you have large trees near your foundation, summer is when they're pulling the most moisture from soil. Watch for settlement or crack changes on the tree side of the house.
I don't have trees close enough to worry about, but Gary's neighbor's tree damage showed up most in late summer.
Exterior Inspection
Summer is the easiest time to walk around the outside of the house. I check visible foundation above grade for cracks, spalling, deterioration. Look at grading, gutters, downspouts. Everything's accessible and visible.
Fall Preparation
October is my second formal inspection. Getting ready for winter.
Pre-Winter Check
I want to know the state of my foundation before winter stress hits. Any problems I find now, I can address before freeze-thaw cycles make them worse. This is the last chance for easy repairs before things get cold and wet.
Moisture Control
I make sure water can't accumulate against the foundation going into winter. Clean gutters. Check downspout extensions. Verify grading still slopes away. Wet soil freezes and expands. Dry soil doesn't push as hard.
A neighbor had ice push against his wall one winter because his drainage was terrible. The frozen, wet soil expanded into his foundation. Could have been prevented with fall drainage work.
Seal What Needs Sealing
If any cracks need sealing, fall is the time. Products cure better in moderate temperatures. And you want cracks sealed before water can get in, freeze, and expand. I sealed one crack in October a few years ago. Perfect timing.
Baseline Measurements
My October measurements establish where things stand going into winter. When I measure in April, I can see if anything changed over winter. The fall baseline makes the spring comparison meaningful.
Winter Awareness
I don't do formal inspections in winter, but I stay aware.
Maximum Crack Widths
Cracks are widest in winter. Cold concrete contracts. This is when my 1/8 inch crack might look like almost 3/16. First time I saw that, I panicked. Now I know it's just thermal contraction. By summer, it'll be 1/8 again.
Interior Checks
Too cold to poke around outside, but I can walk through the basement. Monthly glance at my tracked cracks. Looking for anything dramatically different, any new water, any concerning changes. Usually nothing.
Frost Heave Signs
If the frost line gets deep enough, it can heave the soil under a foundation. Signs include doors suddenly sticking, floors feeling uneven, new cracks appearing. I've never experienced this, but I know what to watch for.
Ice Dam Problems
Ice dams on the roof can force water into walls and eventually to the foundation. If water appears in the basement during winter but not during rain, ice dams might be the cause. Worth checking the roof situation.
Understanding My Baseline
Five years taught me what's normal for my house.
My Seasonal Range
My widest crack varies from about 1/8 inch in summer to maybe 1/8 inch plus in winter. Small variation, consistent every year. I know this because I've measured through every season for five years. That range is my normal.
Year Over Year Stability
The seasonal pattern repeats, but the baseline doesn't drift. January 2024 matches January 2020. Summer 2024 matches summer 2019. No progressive change over the years. That's what stable looks like through seasonal cycles.
When Patterns Change
If my January measurement suddenly showed 1/4 inch instead of my usual winter maximum, something changed. That would concern me. Or if summer didn't close the crack back down to normal minimum. Change in pattern, not just seasonal variation, is the warning sign.
The First Year Challenge
You can't know your baseline without a full year of data. That first January scare happened because I didn't have previous winters to compare. Now I have five. I know exactly what to expect each season.
Helping Gary Understand
His seasonal pattern was different because his crack was active.
Not Seasonal Variation
Gary's horizontal crack was growing every month regardless of season. May, June, July, all showed increasing width. That wasn't thermal expansion and contraction. That was progressive failure.
The Difference
My cracks: winter wider, summer narrower, same range every year. Gary's crack: consistently widening regardless of temperature or season. Mine was cyclical and stable. His was linear and progressing.
Seasonal Confusion
Gary initially hoped his summer measurements would show the crack closing. Nope. It was wider in July than June, wider in August than July. The seasonal pattern that would indicate stability wasn't there. The crack didn't care about the weather. It just kept growing.