Can flexible gas line (CSST) be used to connect a fireplace?
Yes — CSST (flexible corrugated stainless-steel tubing) is a code-approved way to run gas to a fireplace, and it's often easier to route through finished walls and joists than rigid black pipe. It must be installed by a licensed contractor, sized for the load, protected from fasteners, and — critically in our thunderstorm-prone mountains — bonded and grounded for lightning protection.
What CSST is and why we use it
CSST is flexible corrugated stainless tubing, usually in a yellow or black arc-resistant jacket, that snakes through framing where rigid pipe would need a fistful of fittings and elbows. For a fireplace tucked into an interior wall or a long run across a finished home, it can be the cleaner, faster route. It's fully code-listed when it's installed to the manufacturer's instructions — which is the important part.
The rules that keep it safe
CSST has to be sized for the appliance load, shielded from screws and nails with strike plates where it passes through framing, and — the big one in Western NC — bonded and grounded so a nearby lightning strike can't arc through the thin tubing wall and puncture it. Our ridgelines and afternoon thunderstorms make that bonding non-negotiable; we do it on every CSST job. This is precisely the kind of detail that makes gas piping licensed work rather than a hardware-store project.
CSST versus black pipe
Neither is 'better' everywhere — we choose based on the route, the load, and the structure of your home. The final connection at the fireplace is typically a listed flexible appliance connector either way. Whatever we run, we size it, protect it, bond it, permit it, and pressure-test it before gas flows. Call (828) 545-0525 or request a free quote.
How we can help
Related questions
- Does flexible CSST gas line need to be bonded and grounded for lightning protection?
- Can I run a gas line to my fireplace myself?
- Does my existing gas line have enough capacity to add a fireplace?
- Does a new fireplace gas line need to be pressure tested or inspected?
- How much does it cost to run a gas line for a fireplace?
- How do I know if my house has natural gas or propane?
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