St. Louis averages 40 freeze-thaw cycles per winter. Water seeps under damaged shingles, freezes, expands, and cracks flashing and decking. The next thaw allows that water to penetrate deeper. Within two seasons, a small leak becomes structural rot. Partial reroofing services that overlay new shingles on top of damaged underlayment trap moisture between layers, accelerating rot you cannot see. Full tear-off roof replacement exposes that hidden damage and eliminates the moisture trap. Gateway region homes older than 15 years almost always show concealed deck rot during tear-off.
St. Louis roofing contractors who skip deck inspections leave you vulnerable. Local building codes require sheathing replacement when water damage exceeds 25 percent of a panel. We follow those codes because the city inspector will fail your permit if we do not. Installing a new roof over compromised structure is not just bad practice. It is a code violation. Pioneer Roofing St. Louis has worked with city inspectors in every ward and county inspectors in every municipality. We know what passes inspection because we built relationships with the people who enforce the rules.