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Chimney Sheep & Fireplace Draught Excluders
Home Energy & Comfort
Chimney Sheep® & Draught Excluders: the complete guide
Chimney Sheep (and similar wool fireplace draught excluders) sit above the fireplace opening to curb cold draughts, heat loss and soot smells when a fireplace is not in use. This guide covers how they work, when to use them, how to size and fit, key safety rules, and how to pair them with the right chimney cowl for a fully weatherproof setup.
What is a Chimney Sheep (and why it works)
- Inflatable-free solution: a compressible wool pad with a handle/rod that wedges in the flue throat.
- Draught control: reduces warm air escaping up the chimney and cold air sinking into the room.
- Smell reduction: helps tame soot smells and dust on windy or low-pressure days.
- Removable: pull out instantly when you want to light the fire.
Important: a draught excluder is for periods of non-use. For live fires and stoves, manage wind/rain/wildlife at the top with the right cowl: anti-downdraught, spinning, bird-guard or rain caps.
Benefits at a glance
Energy & comfort
- Cuts stack-effect heat loss through unused flues.
- Rooms feel warmer; thermostats cycle less often.
Fast fit, no tools
- Wedge into the throat in minutes.
- Ideal for rented homes and quick wins.
Cleaner air
- Helps reduce soot smells and dust fallback.
- Simple to remove for sweeping or lighting.
How to size a Chimney Sheep (or similar)
- Measure the throat width × depth just above the fireplace opening.
- Go slightly oversize so the pad compresses for a snug seal.
- No ladder? Use our “brick gauge” estimate from the ground and choose the closest pad. See the fit basics in our Installation Guide.
Fitting & safety (quick steps)
- Ensure the fireplace and flue are cold.
- Locate the throat (narrow section 20–40 cm above the opening).
- Insert the pad and compress slightly so it grips around the edges.
- Leave a tiny bleed if the room is damp-prone (prevents condensation).
- Attach a reminder tag so nobody lights a fire with it in place.
Remove before lighting. Always take the draught excluder out before using an open fire or stove.
Draught excluders vs balloons vs cowls
| Need | Best option | Why | Where to look |
|---|---|---|---|
| Stop room draughts when not in use | Chimney Sheep / wool pad | Fast, reusable, no inflation needed | This guide |
| Temporary seal, exact throat sizes | Chimney Balloons | Inflatable, great for seasonal closure | See our Chimney Balloons guide |
| Smoke blow-back when burning | Anti-downdraught / spinning cowls | Stabilise terminal airflow in wind | Anti-downdraught / Spinning |
| Birds, debris or rain ingress | Bird-guard / rain caps | Keep wildlife and water out | Bird-guards / Rain caps |
| Redundant flue needs to breathe | Vent terminal (not sealed) | Avoids condensation and damp | Pepper Pot Vent |
Care & maintenance
- Seasonal check: inspect pad for soot, odours or moisture; air it if needed.
- Keep it clean: vacuum/brush lightly; avoid soaking.
- Routine sweep: maintain your flue annually; remove the pad for access.
Chimney Sheep — FAQs
Will a Chimney Sheep stop downdraught when I light the fire?
No. It’s for non-use periods. For wind-related smoke issues when burning, fit an anti-downdraught cowl or consider a spinning cowl for very exposed sites.
Will it cause damp?
Used correctly with a tiny bleed (if needed) and removed during use, it shouldn’t. Permanently disused flues should have a vent terminal to let the stack breathe.
Is there a “one size fits all” pad?
No. Measure the throat width × depth and choose a size that compresses slightly for a snug fit.
Can I combine a draught excluder with a cowl?
Yes. Use the pad indoors for comfort when unused, and select the right cowl outdoors to handle wind, rain and wildlife while burning.
Next steps
Pair indoor draught control with the right chimney-top solution for year-round performance:
Shop Anti-Downdraught Cowls
Shop Bird-Guard Cowls
Shop Rain Caps
New to fitting? Start with The Ultimate Guide to Installing a Chimney Cowl for safe setup and maintenance tips.
