What is Thimble?
A UL-listed refractory or metal sleeve that lets a stove pipe pass safely through a combustible wall into the chimney. Improperly sized or installed thimbles are a leading cause of wall fires.
Related terms:Pipe ConnectorClearances
All glossary terms
Need a thimble inspection or repair?
We work on thimble every week across DFW. CSIA-certified, written quotes, financing available.
Other terms in the glossary
Creosote
Tar-like residue from incomplete wood combustion. Highly flammable.
NFPA 211
The US standard for chimney, fireplace, and vent system installation.
Inspection Levels
Level 1 (annual), Level 2 (sale/event), Level 3 (concealed damage).
Flue
The internal passage that carries combustion gases up and out.
Liner
Inner channel of the flue — clay tile, stainless steel, or cast-in-place.
Crown
The concrete cap at the very top of a masonry chimney.
10+
Years
4.9★
Rating
CSIA
Certified
< 2hr
Response
Ready when you are
Talk to a CSIA-certified expert today.
Free written quote. Same-week scheduling. 24/7 emergency response when you need it.
Licensed & Insured Same-Week Scheduling Written Quote, Always
Emergency
24/7 Response
Active leak, animal in flue, post-fire damage, or smoke event? Real humans on the line 7 AM to 12 AM every day — replies in under 2 minutes. Tech dispatch within 2 hours during business hours, subject to crew availability after-hours.
Emergency line