When many homeowners think chimney leak, they often think of damage to the chimney structure or exterior masonry. However, your firebox may be the part of your chimney system most affected by a leak. While your firebox is able to withstand the extremely high temperatures generated by a fire, it can be easily damaged by moisture.
If the bricks in the back of your firebox are moving, water entry may be to blame. Even small amounts of water in the fireplace can cause significant damage to the refractory brick, causing it to shift and lose the ability to contain heat from fires. Thankfully, the masonry in the firebox can be repaired so you can enjoy your fireplace again.
How water damages the bricks in your firebox
Although your firebox is built out of masonry, it is very different than the bricks and mortar found in the hearth or chimney. Fireboxes are built using a special refractory brick; this building material radiates and reflects the heat from fires back out into your home. Not only does this help keep you warm on cold winter days, but it also protects the surrounding building materials from the extremely high heat produced in the firebox.
While the masonry in your firebox can withstand extreme heat, it is not meant to withstand water. Because of this, moisture can quickly damage the delicate masonry in the firebox. Common signs of water damage from a chimney leak include cracked or spalling bricks, water stains, or shifting masonry. Even small amounts of water can be enough to cause damage to the delicate masonry.
Causes of chimney leaks
If a chimney leak has caused water damage in your firebox, it is important to uncover the source of the chimney leak. Once the source of the chimney leak is identified and repaired, the firebox can be fixed without worry about the damage reoccurring.
One of the most common causes of chimney leaks is a damaged chimney cap. While the chimney cap protects the flue, if it is damaged in any way water can freely flow into the chimney – and down into the firebox. Chimney crowns, damaged masonry, or faulty flashing have all also been known to cause chimney leaks.
Repairing damaged firebox bricks
If the masonry in your firebox has been damaged by water penetration, it is important to have it repaired as soon as possible to avoid exposing the surrounding building materials to the heat, smoke, and gas produced in the fireplace. One of the most effective ways to repair damaged firebox bricks is through tuckpointing. In the tuckpointing process, the old mortar between bricks is carefully removed before new mortar is applied. Doing this can reinforce the structural stability of the firebox as well as protect the surrounding bricks from damage.
The refractory bricks in your firebox are designed to withstand extreme temperatures, not water entry. If you have moving bricks in your firebox due to water penetration, it is important to call a chimney sweep as soon as possible. For more information on chimney leaks and firebox repairs, contact New Buck Chimney Services today.