Spalling FAQs

Spalling or the crumbling of chimney masonry is a sign that moisture has managed to infiltrate your chimney masonry. Normally, a chimney’s built-in features would prevent water from entering chimney masonry. However, years of exposure to the elements can cause cracks in the masonry and weaken the mortar, creating openings through which water can infiltrate your chimney. 

Aside from wear and tear, what are the usual culprits behind spalling? Why is it bad for your chimney? And, how do you fix and prevent it? We answer your questions here.

What Are the Main Culprits Behind Spalled Bricks?  

• Climate – The freeze-thaw cycle can cause mortar to swell and release, causing the brick to pop and flake off. The chimneys on homes in wet and cold climates are especially prone to spalling. 
• Poor chimney construction – Water can easily seep into chimney masonry if salvaged bricks were used or the chimney wasn’t constructed properly. 

Why Are Spalled Bricks a Problem? 

Moisture weakens the bricks forming your chimney. And, left unattended, it can seep into unaffected parts of the chimney and may even cause it to collapse. Not to mention there’s the risk of mold formation. 

How Do You Fix and Prevent Spalling? 

If the spalling is still in its early stages, tuckpointing or chimney masonry repair can still be done. A chimney professional will remove the old mortar and damaged bricks and replace them. And, to prevent spalling, you can have the chimney masonry waterproofed. A chimney professional will apply sealant to the bricks to keep moisture out. 

It’s also important to have your chimney inspected routinely. Mortar begins to deteriorate after 25 years, but several factors can speed up its deterioration. The sooner chimneys damage can be fixed, the better. 

Chimney Doctors, a locally owned and operated company, offers professional chimney relining, masonry repair and cleaning services. To request an estimate, call us at (518) 882-5009, or fill out this form. We serve homeowners in Saratoga Springs, NY, as well as the surrounding communities.