Do I Need a Tear Off or Can I Do a Layover on My Flat Roof in Chicago?

This is a great question, and it is one that many homeowners get conflicting answers on. In Chicago and Cook County, building code allows a maximum of two roofing layers on a flat roof. That means if you already have two layers in place, you cannot legally install a third roofing membrane. This is not a contractor preference—it is a city and county ordinance, and it matters.

So why do we see so many flat roofs around Chicago with four, five, or even more layers? In many cases, those roofs were installed without permits or without proper inspections. Over time, too much weight from multiple roofing layers can stress the structure and lead to deflection, cracking, or other structural issues. Just because it exists does not mean it is correct or safe.

If your roof currently has one layer and that layer is in good condition, a layover may be allowed. There are important conditions that need to be met. The existing roof must be dry, insulation below must not be wet, and the decking or substrate needs to be sound with no widespread rot or deterioration. If those boxes are checked, installing a second layer can be a code-compliant and cost-effective option.

Once you already have two layers, a full tear-off is required for any new roofing membrane. In some situations, a roof coating like silicone or acrylic can be applied, since coatings do not count as an additional layer. That said, coatings are not always the best solution and depend heavily on roof condition and long-term goals. A proper inspection is the only way to know which option truly makes sense for your roof.

For more roofing tips and helpful guidance, visit our YouTube channel: https://www.youtube.com/@AnchorPointRoofing

Service provided: Roof Replacement

Location: Chicago, IL