How to Break-In Your New Fireplace
Using a new fireplace
Congratulations on your new fireplace or fire pit. Let the summer evenings of marshmallow roasting and fall sunset snuggling begin! A fire feature is a worth-while investment in your property and quality of life. Here’s how to appropriately break in your new investment:
As tempting as it is, don’t build a fire the day your new fireplace is installed. For a fire pit, wait 24 hours before building your first fire. This allows the construction adhesive used to secure the block to set. The first three fires need to be small, starting with a fire that lasts about 20 mins and then slowly cools. The following fire can be progressively bigger, burning longer. By your fourth fire, you can use your fire pit as often as three times a day with longer burning fires.
New fireplace needs much more time to cure. Wait 10 days prior to starting a fire in your new fireplace. Fire places, due to their height are built using mortar. Concrete and mortar made with Portland cement, cures to about 60% of full strength in 24 hours and nearly all of the water used to mix the mortar has been used up in the “hydraulic”, or chemical, reaction. Portland based concrete and mortar, however, doesn’t reach full strength until cured for 28 days, so many masons tell you to wait 28 days until you use the fireplace to be on the safe side. If there has been excessive moisture from humidity, rain or snow, wait the full 28 days.
The refractory materials (firebrick, throat, smoke chamber, & flues) which are the only materials in the new fireplace likely to get very hot, have been made and fired in a kiln, don’t need to be cured and are fully ready to use. The refractory mortar used to lay the firebrick and lining components has not been cured but it is a modern refractory product that can be dried or cured and fired within 10 days.
So, after 10 dry days, or 28 wet days, build a modest wood fire in your new fireplace. It would be best to do this for the first 3 fires and then progressively build larger fires till you’ve reached a reasonable size fire for your fireplace structure.