10″ to 16″
The 10”-16” diameters are listed to UL 103 Type HT. That means our 10”-16” chimney system is perfectly suited for hightemperature appliances, making it ideal for factory-built fireplaces, large masonry fireplaces, and boilers.
18″ to 24″
The 18”-24” diameters are listed in the US to UL 103. In Canada, the 10”-24” diameters are listed to CAN/ULC-604. The DuraTech LDC may also be used on specific factory-built fireplaces listed to CAN/ULC-610 & UL 127.
US Listings:
- UL 103 Type HT in 10”-16” diameters
- UL 103 in 18”-24” diameters
Canada Listing:
- CAN/ULC-604 in 10” – 24” diameters