REFRACTORY MORTAR (HEAT STOP)
High Temperature-Resistant Refractory Mortar
Heat Stop® Products are ready to use high temperature mortars designed specifically for residential fireplace construction. This refractory cement/mortar is specified by building codes because it can withstand fireplace operating temperatures in excess of 800-dm F. The following Heat Stop® products are available.
• Heat Stop® -premixed
Water soluble and ready to use as a regular refractory cement. Available in 15 lb can or 50 lb pail.
• Heat Stop® II -Dry Mix
Non-water soluble mix for firebrick and flue installations. Sets fast and resists flue joint washout. Ready to use with the addition of water. Available in 10 lb pail.
• Heat Stop® 50 -Dry Mix
Same as Heat Stop II only in a 50 lb bag
• Heat Stop® "Flue Glue" -Dry Mix
Non-water soluble mix designed specifically for the maintenance and repair of existing masonry such as clay flues and firebrick. "Flue Glue" is stronger, less porous, and more water and chemical resistant than any other refractory mortar for residential and commercial service. This product works particularly well for replacing broken firebrick, refilling old mortar joints, repairing broken or chipped clay flue lining. "Flue Glue" is available in 5 lb pails.
All Heat Stop products including Insul Stick meet or exceed the requirements of ASTM C-199, ASTM C-1283, ASTM E-136 and NFPA-211.
The Top Ten Most Frequently Asked Questions
Regarding Heat Stop Refractory Mortar Products
by Bob Rucker, 2006
1. Q. How long should we wait after installation before heat may be applied to fireplace or chimney?
A. With regard to firebrick, clay flue lining or any of the Heat Stop refractory mortar products simply wait one day after all of the masonry in the fireplace or chimney has been installed.
2. Q. What are the Heat Stop product types?
A. There are only two as follows:
1. Heat Stop in a 1 gallon (15 lb.) pail or a 3 gallon (50 lb.) pail. Premixed and ready to use.
2. Heat Stop-II in a 1 gallon (10 lb.) pail and Heat Stop-50 in a 50 lb. bag. Same producte but different size container. Add water, mix and ready to use.
3. Q. Which of the Heat Stop products is the least expensive?
A. Heat Stop-50, the dry mix in the 50 lb. bag is least expensive. A 50lb. bag when mixed with water yields approximately 60 lbs.
4. Q. Which of your products is the best for installation of clay flue lining and why?
A. Heat Stop II or Heat Stop-50 are the best for installing clay flue lining because they are completely non water soluble in service after the initial set. This type of product is specified by the NFPA-211 (National Fire Protection Association).
5. Q. What A.S.T.M. (American Society for Testing Materials) specifications are called out by local and national building codes regarding fireplace and chimney construction?
A. For refractory mortar ASTM C-199 (medium duty). All Heat Stop products meet or exceed this requirement. Firebrick ASTM C-27. Clay Flue Lining ASTM C-315. Clay Flue Lining Installation ASTM C-1283.ASTM C-105 is a discontinued specification for fireclay and should not be used. Fireclay mixes with regular mortar do not meet any building code, anywhere.
6. Q. Where are Heat Stop refractory products available?
A. Wherever firebrick and clay flue lining are sold. Try your favorite masonry supply yard and or concrete block manufacturer.
7. Q. Which of your Heat Stop products may be colored and how?
A. Heat Stop-II or Heat-50 will work with mortar color just like any regular masonry mortar. Follow the mortar color manufacturers instructions as if Heat Stop-II or Heat Stop-50 was a regular mortar.
8. Q. How thick should the Heat Stop refractory mortar products joint thickness be?
A. Joint thickness is recommended at --1/16" to 1/8" thick. If a thicker joint is required (up to 3/8" thick) we recommend the use of the dry mix Heat Stop-II or Heat Stop-50.
9. Q. Which of the Heat Stop refractory mortar products is most popular.
A. Every year Heat Stop-50 is used more than any of the other products. The reasons why follow:
1. Heat Stop-50 is the least expensive.
2. Heat Stop-50 (or Heat Stop-II) may be used for firebrick or clay flue installations with up to 3/8" thick joints.
3. Heat Stop-50 (or Heat Stop-II) may be easily colored with mortar color.
4. Heat Stop-50 (or Heat Stop-II) is non water soluble in service.
5. Heat Stop-50 (or Heat Stop-II) has an indefinite shelf life.
6. Heat Stop-50 (or Heat Stop-II) has excellent drying characteristics no matter the humidity.
10. Q. How long have the Heat Stop refractory mortar products been in service?
A. Since the 1970's in several hundred thousand residences all over the world.