Quick Answer
A wood stove chimney installation follows seven decisions in a fixed order: match the chimney diameter to the stove's flue collar, choose a through-the-ceiling or through-the-wall route, hold the listed clearance to combustibles at every point, land the system's weight on one listed support, brace the vertical run, meet minimum height above the roof, then seal and cap the penetration.
For Shasta Vent All-Fuel HT Chimney, the numbers are specific. Clearance to combustibles is 2 inches. Each load-bearing support is rated for up to 50 feet of chimney. Wall brackets go on at least every 10 feet. Anything more than 5 feet above the roof penetration needs stabilizing.
Connector pipe is a separate product with separate clearances: 18 inches for single-wall, 6 inches for double-wall. The first two decisions, diameter and route, are the only ones you cannot revise without starting over.
What a Wood Stove Chimney Installation Actually Involves
Most people picture the install as the day the pipe goes up. The install is really a planning problem that ends in a few hours of assembly.
Every decision below constrains the ones after it. Diameter constrains which parts exist. Route constrains what components you need and how the weight is carried. Clearance constrains where the pipe can pass. Height constrains how much bracing you need above the shingles.
Work them in order and the parts list writes itself. Work them out of order and you will be buying twice.
This page is the map. Each step links to the full article on that step, and to the parts that step needs. If you want the assembly procedure rather than the planning sequence, start with our step-by-step Class A chimney pipe installation guide.
Step 1: What Size Chimney Pipe Do You Need?
The answer comes from the appliance, not from the space, the budget, or the internet.
Your stove's installation manual specifies a flue collar diameter. The chimney matches it, from the collar to the cap, with no reductions anywhere in the run. Most modern EPA-certified wood stoves use 6 inch. Larger fireboxes and older non-EPA stoves often use 8 inch.
Reducing below the collar size restricts flow, weakens draft, and puts the installation outside the tested and listed configuration of both the stove and the pipe. That is not a judgment call. There is no short section where it becomes acceptable.
Shasta Vent All-Fuel HT Chimney is manufactured in 6 inch and 8 inch inside diameters.
Go deeper: what size chimney pipe do I need for my wood stove and 6 inch vs 8 inch chimney pipe. If your stove has a 4 inch collar, read what 4 inch chimney pipe is actually for before ordering anything. Pellet appliances follow different rules entirely, covered in our pellet stove venting guide.
Shop by diameter in chimney pipes.
Step 2: Through the Ceiling or Through the Wall?
There are two routes, and they need different parts.
Through the ceiling. The pipe rises straight from the stove, through a ceiling support box, through the attic, and out the roof. Straight vertical runs draft best because there is nothing slowing the flow. This route needs a ceiling support box, an attic insulation shield, roof flashing, a storm collar, and a cap.
Through the wall. The connector runs horizontally through a wall thimble, meets a tee outside, and turns vertical up the exterior of the house. Common in retrofits and cabins where cutting through an upper floor is not practical. This route needs a wall thimble, a tee with cleanout cap, a tee support, wall brackets, and a cap.
Through-the-wall runs put the chimney in outdoor air, which cools the flue. That is a real draft consideration, not a small one, and it is one reason insulated Class A pipe matters more on exterior runs than interior ones.
Go deeper: planning a through-the-wall installation and the ceiling support box guide. If you plan to enclose an exterior run to match the house, read the chimney chase guide before framing anything.
Complete kits for both routes: 6-Inch Thru-The-Ceiling Kit, 8-Inch Thru-The-Ceiling Kit, 6-Inch Thru-The-Wall Kit, and 8-Inch Thru-The-Wall Kit. All of them live in full system kits.
Step 3: What Clearances Do You Have to Hold?
There is no single clearance number for a wood stove install. There are three, and they differ by more than a foot.
- Class A chimney pipe: 2 inches to combustibles for Shasta Vent All-Fuel HT, held for the full height of the run, in the open or inside a chase.
- Double-wall connector pipe: 6 inches to combustible walls and ceilings.
- Single-wall connector pipe: 18 inches to combustible walls and ceilings.
Connector pipe is the black stove pipe between the appliance and the ceiling or wall. It is not chimney pipe, and it never passes through a wall, ceiling, or roof.
Clearance is an air space. It cannot be filled with insulation, caulk, framing, or anything else, and it applies on all sides. Where the chimney passes near building insulation, an insulation shield keeps that insulation off the pipe. On Shasta Vent systems the shield is required wherever insulation or debris could reach the chimney, which in practice means the attic on nearly every through-the-ceiling install.
Go deeper: chimney pipe clearances, how far from combustibles.
Parts: ceiling and firestop components and the attic insulation shield.
Step 4: What Carries the Weight, and What Holds It Steady?
Support brackets do two different jobs and people mix them up constantly.
Load-bearing supports carry weight. On an interior run that is the ceiling support box. On an exterior run it is the tee support. Each Shasta Vent support is rated for up to 50 feet of chimney, and a taller system may need an additional one partway up.
Bracing holds the chimney plumb. Adjustable wall brackets provide lateral stability and carry no weight. They go on at least every 10 feet unless the chimney is already secured at that point by a ceiling support box, tee support, or firestop radiation shield. The bracket adjusts from 2 to 8 inches of standoff, and 2 inches is the floor, not a suggestion.
Every bracket lands on framing, added blocking, or sound masonry. Siding and sheathing are not attachment points.
Offsets need their own support. Elbows cannot carry the chimney above them. Shasta Vent systems allow a maximum of two offsets and returns, four elbows total, at 15 or 30 degrees, and elbows cannot be stacked to make a steeper angle.
Go deeper: chimney support brackets, wall bracing vs roof bracing.
Parts: support and brackets, tees and accessories, and elbows and elbow kits.
Step 5: How Tall Does the Chimney Have to Be?
Two separate requirements govern height, and you have to satisfy both.
Clearance above the roof. The 3-2-10 rule: at least 3 feet above the point where the chimney passes through the roof, and at least 2 feet higher than anything within 10 feet horizontally. On a steep roof, or with the penetration low on the slope, the second condition governs and the required height climbs well past 3 feet.
Total system height for draft. Most stove manufacturers call for roughly 15 feet of total flue from the stove outlet to the cap. A chimney can pass both 3-2-10 checks and still draft poorly if the total run is short, which happens most often in single-story homes.
Height feeds straight back into Step 4. Once more than 5 feet of chimney stands above the roof penetration, it has to be stabilized, with additional supports at intervals of no more than 5 feet after that.
Go deeper: the 3-2-10 rule explained, how tall should your chimney be, and does a taller chimney draft better.
Step 6: How Do You Keep Water Out?
Chimney leaks almost never come from the pipe. They come from the roof penetration.
Flashing is matched to the roof pitch and installed under the shingles above it and over the shingles below it, so water sheds over the top of it. The storm collar goes on above the flashing, wraps tight to the pipe, and gets a bead of high-temperature sealant at the top edge. The cap keeps rain, debris, and animals out of the flue and holds sparks in.
On a through-the-wall install, the wall thimble does the equivalent job at the wall. Shasta Vent thimbles adjust for walls up to 10 inches deep, and the air space between the pipe and the thimble stays open. Filling it defeats the thing it exists to do.
Parts: flashing and roof components and caps and finishing pieces.
Step 7: What to Check Before the First Fire
Walk the whole system before you light it.
- Every locking band engaged and secured
- Vertical sections plumb, horizontal connector sloped at least 1/4 inch of rise per foot back toward the chimney
- Clearances verified at every penetration and every bracket standoff
- Insulation shield in place and insulation pulled back from it
- Flashing, storm collar, and cap installed and sealed
- All components from the same listed system, unmodified
That last one is not a formality. Mixing components from different chimney systems or manufacturers voids the listing and the warranty, and it is one of the first things an inspector looks for.
Build your first fire small and let the system come up to temperature gradually.
Full parts breakdown: chimney pipe components explained and the ultimate guide to wood stove chimney pipe.
Do You Need a Permit?
In most jurisdictions, yes. A wood stove and its chimney are a permitted mechanical installation, and many insurers ask for proof of a passed inspection before they will cover the appliance.
Code adopts differently from state to state, county to county, and city to city. NFPA 211 is the standard most residential requirements trace back to, but what your inspector enforces is whatever your jurisdiction has adopted, and that changes over time. Call the building department before you buy, not after the walls close up.
Go deeper: chimney code requirements for wood stove installations.
What Shasta Vent All-Fuel HT Chimney Is
If you are comparing systems, here is the spec in one place.
- 6 inch and 8 inch inside diameters
- Double-wall, solid-filled construction with a 1 inch wall
- .020 inch type 304 stainless steel inner and outer walls
- 2 inch clearance to combustibles
- Twist-lock end rings and locking bands
- ETL Listed by Intertek to the HT requirements of UL 103
- Limited lifetime warranty to the original homeowner
Type 304 stainless resists corrosion better than the 430 stainless or aluminized steel used in some competing systems, which matters most on the exterior runs and the cooler top sections where condensation forms.
Not sure which components your layout needs? Our chimney planning guide walks through it, or browse the full catalog.
Frequently Asked Questions
Can I install a wood stove chimney myself?
Many homeowners do, and the assembly is not complicated. The planning is where installs go wrong, and roof work carries real risk. Check whether your jurisdiction permits homeowner installation and whether your insurer requires a professional installer, because both answers vary by location.
How long does a wood stove chimney installation take?
The assembly is usually a day for a straightforward run. Planning, permitting, and inspection scheduling take considerably longer, and that is the part worth starting early. Lead times get long once burning season begins.
What is the difference between stove pipe and chimney pipe?
Stove pipe, also called connector pipe, runs from the appliance to the ceiling or wall and is designed to radiate heat into the room. Chimney pipe is insulated Class A pipe listed to UL 103 HT, and it is the only thing that passes through a wall, ceiling, attic, or roof. They are not interchangeable at any point.
How close can chimney pipe be to wood framing?
For Shasta Vent All-Fuel HT, 2 inches, held on all sides for the full height of the run. Connector pipe is different: 6 inches for double-wall and 18 inches for single-wall. The space has to stay as open air.
Do I need a chimney support box and wall brackets?
Usually both. One load-bearing support carries the weight, either a ceiling support box or a tee support, and wall brackets keep the run plumb against wind. They do different jobs and one does not substitute for the other.
How high does the chimney have to go above the roof?
At least 3 feet above the roof penetration and at least 2 feet above anything within 10 feet horizontally. On steep roofs the second condition often governs and pushes the height well past 3 feet.
Can I use elbows to get around a joist or rafter?
Within limits. Shasta Vent systems allow a maximum of two offsets and returns, four elbows total, at 15 or 30 degrees, with support at every offset. Every bend slows draft, so a straight run is better whenever the framing allows it.
Can I mix brands to save money on parts?
No. Chimney components are listed as a system and tested together. Mixing manufacturers voids the listing and the warranty, and inspectors check for it.
What maintenance does a Class A chimney need?
Annual inspection and cleaning by a qualified professional, which is also a condition of the Shasta Vent warranty. Stainless steel needs specific cleaning tools, covered in how to clean a Class A stainless steel chimney pipe safely.
Disclaimer
This article reflects our own research and our experience manufacturing Class A chimney systems. It is general education and a planning overview, not installation instructions for your specific product or your specific building.
The governing documents are your appliance manufacturer's installation instructions, your chimney system's installation instructions and listing, and the codes adopted in your jurisdiction. Code adopts differently from state to state, county to county, and city to city, and requirements change over time. Where any of those disagree with this page, they win.
Do your own research and verify it locally. Read both sets of manufacturer instructions before you buy anything, and talk to your local building official, a licensed installer, or a CSIA-certified chimney professional when the answers are not clear. Shasta Vent recommends confirming all measurements, components, and procedures with a qualified professional before beginning any installation.
