Protecting Heritage Oak During Concrete Slab Construction

100+ year old western black oak in Oregon; concrete slab planned 10 ft from trunk. Owner heard perforated pipes under slab let roots "breathe."

Pipes Don't Help

Problem is root severance, not air. Roots in top 6-18 inches. Cutting >20% of root zone causes canopy dieback.

Root Zone Math

Imagine circle at drip line. Slab cuts through like a pie slice. If >20% of circle damaged, expect dieback. At 10 ft from trunk of large oak, likely exceeds 20%.

Better Alternative

Raised wood deck instead of concrete—minimizes root disturbance.

Expert Consultation

Contact Oregon Dept of Forestry or city urban forester for on-site assessment.

Oregon Forestry Contacts