How Do You Install Double Wall Stove Pipe?

What Is a Double Wall Stove Pipe?

Double wall stove pipe (also called close-clearance connector pipe) is a two-layer pipe used inside the room to connect your wood stove to a chimney system. The air gap between the inner and outer walls insulates the pipe, keeping the outer surface cooler and allowing reduced clearances to combustible materials per NFPA 211.

It is not the same as Class A insulated chimney pipe, which is UL 103 HT listed and designed to pass through walls, ceilings, and roofs. Double wall stove pipe stays inside the room only.

Double Wall vs. Single Wall Stove Pipe

For a detailed look at single wall installation, see our guide on how to install single wall black stove pipe.

What You Will Need

• Double wall stove pipe sections (typically 6" or 8" diameter - match your stove's flue collar)
• Stove adapter (connects the stove collar to double wall pipe)
• Elbows (45-degree or 90-degree, if bends are needed)
• Telescoping pipe (for adjustable lengths - makes fitting much easier)
• Ceiling support box or wall thimble (pre-installed before pipe work begins)
• Manufacturer-approved screws
• Drill or screwdriver
• Measuring tape
• Heat-resistant sealant (optional, for the stove collar connection)

Before You Start

Read the manufacturer's instructions for your specific pipe brand. Each brand may have different requirements for screws, overlaps, and support points. Always follow the stricter of either the manufacturer's specs or your local building code.

Check your clearances before buying materials. Double wall stove pipe requires 6 inches from combustible walls and 8 inches from combustible ceilings per NFPA 211. If your walls or ceiling are non-combustible (like bare concrete or brick), clearance can be reduced to 0 inches, but never allow direct contact.

Plan your layout on paper first. Measure the distance from your stove collar to the ceiling support box or wall thimble. Keep the run as short and straight as possible. Every elbow and horizontal stretch reduces draft and increases creosote risk. If you need help planning, use our free chimney design service for a custom layout within 24 hours.

Step-by-Step Installation

Step 1: Attach the Stove Adapter

Place the stove adapter onto your wood stove's flue collar. This adapter transitions from the stove outlet to the double wall pipe system. Secure it with the provided screws. Some adapters have a twist-lock mechanism instead.

Step 2: Add Pipe Sections Upward

Stack additional double wall pipe sections upward from the adapter. Follow the seam arrows printed on the pipe - they show the correct assembly direction. Each section locks into the one below it. If you need a custom length, use a telescoping section rather than cutting the pipe (most double wall pipe cannot be cut).

Step 3: Install Any Elbows

If your stove is not directly below the ceiling support box, use elbows to offset the pipe. Stick to 45-degree elbows whenever possible - they cause less draft restriction than 90-degree bends. For help calculating elbow offsets, see our elbow offset measurement guide.

Step 4: Secure Where Required

Screws are generally only used at the stove connection and at the ceiling support box, depending on your manufacturer's guidelines. Do not over-secure the pipe with screws along its length unless the instructions call for it. Wall brackets or support straps may be needed for longer vertical runs to keep the pipe stable.

Step 5: Maintain Proper Clearance

Double-check all clearances before making final connections. Keep 6 inches from combustible walls and 8 inches from combustible ceilings at every point along the pipe run. Use a measuring tape at multiple spots. Never allow the pipe to touch wood framing, drywall, or other combustible surfaces.

Step 6: Connect to the Transition Point

Insert the final pipe section into the ceiling support box or wall thimble. The inner liner of the double wall pipe should extend into the transition fitting. At this point, the system transitions to Class A insulated chimney pipe (UL 103 HT listed), which continues through the ceiling, attic, and roof with just 2 inches of clearance to combustibles.

Step 7: Final Checks

Before firing up your stove, verify every connection point. All seams should be tight and aligned. No inner liner should be exposed between sections. Apply heat-resistant sealant at the stove collar if recommended by your pipe manufacturer. Make sure you can see no daylight through any joints.

Safety Rules to Remember

• Never use stove pipe (single or double wall) through walls, ceilings, or roofs. Switch to Class A chimney pipe at the transition point. For more details, see our building codes guide.
• Horizontal pipe must rise at least 1/4 inch per foot toward the chimney.
• Keep runs short and straight to improve draft and reduce creosote buildup.
• The chimney must meet the 3-2-10 rule: extend at least 3 feet above the roof penetration and at least 2 feet higher than anything within 10 feet.
• Inspect and clean your chimney system at least once per year to prevent creosote buildup and chimney fires.

Not Sure Which Setup Is Right for You?

If you are unsure whether you need double wall or single wall stove pipe, or if you want help planning your full chimney system from stove to rooftop, use our free chimney design service. Send us your room measurements and stove specs, and we will send you a custom recommendation within 24 hours. You can also call us at 888-834-0880 (9 AM - 9 PM, 7 days a week) or browse our complete chimney kits for a ready-to-go solution.

Frequently Asked Questions

Can double wall stove pipe pass through a wall or ceiling?

No. Double wall stove pipe is only rated for use inside the room, from the stove to the ceiling support box or wall thimble. At that transition point, you must switch to UL 103 HT listed Class A chimney pipe, which is insulated and rated to pass through combustible walls, ceilings, and roofs with just 2 inches of clearance.

What is the clearance for double wall stove pipe to combustibles?

Double wall stove pipe requires 6 inches of clearance to combustible walls and 8 inches to combustible ceilings, per NFPA 211 and most manufacturer specifications (such as DuraVent DVL). Single wall stove pipe requires 18 inches to all combustible surfaces.

Can I mix single wall and double wall stove pipe in the same run?

Generally no. Most manufacturers do not allow mixing single wall and double wall pipe in the same connector run. If you start with double wall, the entire connector from stove to transition point should be double wall. Always check your manufacturer's installation manual.

Do I need double wall stove pipe for a manufactured home?

Yes. HUD standards require double wall (close-clearance) connector pipe in manufactured homes and mobile homes. Single wall stove pipe is not permitted. For a full guide, see our article on installing a chimney in a mobile home.

Need More Information?

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