Okay, let's break down the firestopping requirements for a single-family home rough-in inspection in Tennessee, focusing on the most likely scenarios and interpretations of the codes. It is important to always consult the official documents provided by your local and state authorities.

General Understanding

The purpose of firestopping is to slow down the spread of fire and smoke within concealed spaces of a building, giving occupants more time to escape and firefighters more time to respond. The specific requirements vary based on the building type, construction materials, and occupancy.

What Code Cycle is Tennessee Using?

This is the MOST IMPORTANT starting point. Tennessee generally follows the International Codes (I-Codes), and you need to know which edition is currently adopted by the state. As of November 2024, Tennessee is using the 2018 International Building Code (IBC) and the 2018 International Residential Code (IRC).

The 2018 International Residential Code (IRC) and Firestopping

Since you are building a single-family dwelling, the IRC is likely the controlling code document here. Here's what you need to know:

Section R302.11 Fireblocking

This is the section that pertains to firestopping. Read it closely.



General Requirement

Fireblocking shall be installed to cut off all concealed draft openings and to form an effective barrier between stories, and between a top story and the roof space.

Locations Requiring Fireblocking

In concealed spaces of stud walls and partitions, including furred spaces. (In other words, walls between studs) At all interconnections between concealed vertical stud wall or partition spaces and concealed horizontal spaces such as soffits, drop ceilings, cove ceilings, and similar locations. In interior stud walls and partitions at the ceiling and floor levels. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level. Fireblocking must be installed in concealed locations, such as attics and furred walls.

Acceptable Materials for Fireblocking

Two-inch (51 mm) nominal lumber. Three-fourths-inch (19.1 mm) wood structural panels with joints backed by 3-inch (76 mm) lumber. Three-fourths-inch (19.1 mm) particleboard with joints backed by 3-inch (76 mm) lumber. One-half-inch (12.7 mm) gypsum board. One-fourth-inch (6.4 mm) cement board. Mineral wool, glass fiber or rock wool insulation. Other approved materials.

R602.8 Fireblocking. States more or less the same thing as above.

Interpreting the Requirements for Your SituationLet's translate the code into practical terms for your house build:1.

Wall Cavities

The spaces inside the stud walls need fireblocking. This is primarily achieved by the top and bottom plates, but you might need additional fireblocking in certain situations if the wall cavity is unusually tall. For example, if your wall exceeds 10ft, you must add a firestop at that point.2.

Penetrations Through Walls, Floors, and Ceilings

This is where the fire caulk/foam comes in. The code requires that openings around pipes, ducts, cables, and wires at ceiling and floor levels be fireblocked. This means that if you have plumbing pipes or electrical wires running from the basement (or crawlspace) up into a wall cavity, the gap around the pipe or wire where it passes through the top plate of the floor below needs to be sealed. The same applies if these services penetrate the ceiling.3.

Attic and Crawlspace

These areas need to be properly fireblocked, especially at connections between walls and the attic/crawlspace.

How to Comply with Firestopping Requirements



Gaps around penetrations

Use a fire-rated caulk or foam specifically designed for this purpose. Make sure the product is listed and labeled for its intended use (e.g., sealing penetrations through gypsum board or wood). Follow the manufacturer's instructions for application (joint width, depth, etc.).

Wall Cavities

Ensure the top and bottom plates of the walls are tight-fitting. If there are gaps, you may need to fill them with fireblocking materials.

Around Fireplaces and Chimneys

Pay special attention to firestopping around chimneys and fireplaces, as these are potential fire hazards.

Addressing the Conflicting InformationThe conflicting information you're seeing likely stems from:

Different Code Interpretations

Inspectors can have varying interpretations of the code.

Local Amendments

Even though Tennessee follows the I-Codes, local jurisdictions may have amendments that add or modify requirements. This is rare in TN, but ALWAYS verify.

Misinformation

Online forums and DIY articles can sometimes contain incorrect or outdated information.

What to Do Now1. Confirm the Code Cycle



Contact your local building department or the Tennessee State Fire Marshal's Office to definitively determine which edition of the IRC (or IBC) is in effect for your project. This is the single most important step.2. Consult with the Inspector

Talk to the inspector who will be performing the rough-in inspection. Ask them specifically about their expectations for firestopping penetrations. Get it in writing if possible.3.

Review the Plans

If you have architectural plans, review them carefully. They may specify firestopping details.4.

Over-Prepare (Slightly)

If you're unsure, it's generally better to over-prepare than under-prepare. Sealing around penetrations with fire-rated caulk/foam is a relatively inexpensive and easy task, and it can save you from failing the inspection.

Example Scenario

Let's say you have a plumbing pipe running up from the crawlspace and through the bottom plate of a wall. Here's what you should do:1. Clean the Area

Make sure the area around the pipe penetration is clean and free of debris.2.

Apply Fire-Rated Caulk

Use a fire-rated caulk specifically designed for sealing penetrations through wood. Apply it generously to completely fill the gap around the pipe.3.

Smooth the Caulk

Use a wet finger or a putty knife to smooth the caulk and ensure it adheres properly to the pipe and wood.

Important Considerations Product Selection

Use only fire-rated caulk and foam that are listed and labeled for their intended use. Read the manufacturer's instructions carefully.

Installation

Follow the manufacturer's instructions for installation. This includes joint width, depth, and curing time.

Documentation

Keep records of the fire-rated products you used, including the manufacturer's name, product code, and listing information. This may be helpful if the inspector asks for documentation.

Final Recommendations Err on the side of caution: Apply fire caulk / foam to penetrations at ceiling and floor levels. Focus on the most common areas

Pay special attention to sealing around pipes and wires, especially where they pass through top and bottom plates.

Be proactive

Talk to the inspector early in the process to clarify their expectations.

Have documentation on hand

Keep copies of product data sheets and any relevant code sections.By taking these steps, you can increase your chances of passing the rough-in inspection and ensuring that your house is properly firestopped. Remember, firestopping is a critical safety feature, so it's worth the extra effort to get it right.

Disclaimer: I am an AI chatbot and cannot provide professional building code advice. This information is for general guidance only. Always consult with a qualified building inspector or code official for specific requirements in your area. Flag for review