InstaBidsFor homeowners
Types of chimney: which one fits your home?
In one federal test series of five chimneys: Masonry chimney (clay tile liner) is better for keeping the wood enclosure around it cooler during a chimney fire (NBS, 1983). The right choice depends on how hot the enclosure around the chimney gets in a chimney fire and how the cap, cricket or roof flashing keeps water out.
| Type | Best for | Main advantages | Main drawbacks |
|---|---|---|---|
| Masonry chimney (clay tile liner) | keeping the wood enclosure around it cooler during a chimney fire (NBS, 1983) | NBS (1983): "because of the chimney's high mass, temperatures on the outside brick surface never approached an unacceptable level" | NBS (1983): "The fire clay flue lining of the masonry chimney was severely cracked during the chimney fire"; HUD (2000): without a hood it should have "stone or reinforced concrete caps at the top"; HUD (2000): on the side of a pitched roof, "a cricket is needed on the higher side to divert water around the chimney" |
| Air-insulated factory-built metal chimney | no official source names one | NBS (1983): after four creosote burnouts, "Flue linings were undamaged." | NBS (1983): "The highest enclosure temperatures were noted during tests of the air-insulated chimney"; NBS (1983): its galvanized outer pipe dulled; not an immediate problem, but "the loss of galvanization would lead to corrosion over longer periods of time"; HUD (2000): if it is not encased, "check the adjustable flashing at the roof" |
| Solid-packed factory-built metal chimney | no official source names one | NBS (1983): for two solid-packed chimneys, "no damage was apparent on the interior or exterior of the chimneys" | NBS (1983): one solid-packed chimney, tested outdoors, had damage that was "more significant"; HUD (2000): in a chase, "water should drain off the enclosure" |
InstaBids is an AI-run marketplace for homeowners and property managers: describe a home job once, by chat or through your own AI assistant, add photos, and get multiple written quotes on the same scope, compared apples to apples, with no phone calls or home visits before you pick.
Post your job on InstaBids, and contractors can bid in writing on one written scope.
- Describe it onceBy chat, or through your own AI assistant, and add photos.
- Post it and send itContractors bid in writing on that scope.
- Compare line by lineEvery quote is written against the same scope.
- You chooseContact details stay hidden until you pick and they confirm.
For your AI assistant
MCP connector · REST API · plain HTMLHand any of these to your assistant and it can help you write this job's request; you send the request yourself. What you type in the job box above goes into the prompt these buttons carry. The connector asks you to sign in to your InstaBids account the first time.
- MCP connector URL
https://instabids.ai/api/agent/mcp - Agent API (OpenAPI)
https://instabids.ai/openapi.json - Start-request link
https://instabids.ai/intake?from=options-chimney&utm_source=us&utm_medium=page&utm_campaign=options&page_type=options#job=chimney%20repair%20or%20rebuild - Prompt for any AI, with your job
- ChatGPTOpens with the prompt
- ClaudeOpens with the prompt
- GrokOpens with the prompt
- GeminiCopies the prompt, then opens
Every page is plain HTML. Steps for every assistant: add to your assistant.
| Priority | Choose |
|---|---|
| a wood enclosure that stays cooler during a chimney fire (NBS, 1983) | Masonry chimney (clay tile liner) |
Get written bids
Contractors who take part bid on one written scope card, so nobody visits before you see any prices.
The contractor you pick may visit once before settling the final price against the percentage the bid stated.
Contractors in your trade see the scope card and your 5-digit ZIP code.
Contact details stay hidden until the homeowner picks a contractor and they confirm the connection.
Homeowners pay InstaBids nothing.
Sources for the facts on this page
- National Bureau of Standards (now NIST), Center for Fire Research, Intensity and Duration of Chimney Fires in Several Chimneys, December 1983, prepared for the U.S. Consumer Product Safety Commission and the U.S. Department of Energy, government, read 22 October 2026.
- U.S. Department of Housing and Urban Development, Residential Rehabilitation Inspection Guide (February 2000, prepared by the National Institute of Building Sciences), government, read 22 October 2026.