How Many Roofs Can I Have on My Building?

According to State Regulations in North and South Carolina and IBC Guidelines you can only have 2 roofs on a building. 

When considering a roof replacement or renovation, a common question arises: how many roofs—or roof layers—can I legally have on my building? The answer depends on a mix of structural safety, local building codes, and best practices. Let’s break it down according to the North Carolina and South Carolina building codes and International Building Code (IBC).

What the International Building Code (IBC) Says

The International Building Code (IBC) is the model code used in most U.S. states, including NC and SC. Under IBC Section 1511.3, titled Recovering versus Replacement, the IBC limits the number of roof layers to two.

This rule exists to avoid excess structural weight, prevent moisture entrapment, and ensure fire and wind resistance aren’t compromised.

Roof Recovering vs. Roof Replacement

• Recovering: Installing a new roof over an existing one or tearing off the current second roof and then laying down a new roof over the original roof. 
• Replacement: Removing the old roof or roofs down to the deck and starting fresh.

You cannot recover a roof if it has:

• Water damage or saturated insulation
• More than two existing layers
• Fire or structural concerns

North Carolina Roof Layer Regulations

North Carolina follows the IBC in the North Carolina State Building Code. The rules are clear:

• No more than two layers are allowed
• A tear-off is required after two layers

South Carolina Roof Layer Regulations

South Carolina also follows the IBC via the South Carolina Building Codes Council:

• Maximum of two roofing layers
• Removal required beyond two layers

Why WNC Roofing Often Recommends Full Roof Replacement

While recovering a roof may be allowed, we typically recommend full tear-offs for:

• Any roof with wet insulation 
• Facilities with structurally compromised, rotten or rusting roof decking