Professional Repairs for Chimney Leaks
Porous bricks, cracks in mortar, cracks in crown, openings at top edge of flashing, the improper use of flashing, improper use of house wrap (Tyvek, tar paper, etc.), cracks in flashing cement(tar) and/or failure in roof shingles are all possible causes of a chimney leak. Diagnosing the leak’s frequency in accordance with recent and past storm history will help determine the most likely cause. With the right clues and a thorough inspection of all threats visually, a recommendation can then be made that will best repair the leak.
Brick, stone, rock, tile, stucco are popular chimney coverings. All of these surfaces require maintenance to ensure water cannot penetrate the outer surface. If the stucco or mortar fail, immediate leakage and/or erosion of mortar can occur. Re stucco, re-pointing, re-crowning or Silicone waterproofing are different ways of repairing these coverings.
Cedar shingles, clapboard, vinyl and stucco (Drivet) are common chimney coverings that utilize tar paper or house wrap (Tyvek) to shed penetrating water over metal roof flashing at bottom of wall. This is the common step, apron, wrap flashing method used along roofing/siding joints on 90% of new construction today (by code). When installed properly this metal flashing – roofing – vapor barrier combo can last up to 50 years using our standard aluminum flashing – Timberline HD roofing – 30 lb. wall felt paper.
Chimney chases are the new design in chimneys. They are hollow plywood boxes (usually encasing a gas fireplace/burner stack, but sometimes just for show) covered with any (brick, wood, stone, stucco, etc). The flashing is the common wall flashing system with house wrap. What makes these chimneys unique is the different ways the builder (finisher) covers the chimney top. Proper use of overlapping Bitumen roofing with proper use of primers, flashing, fiberglass, capping and coping is essential. Many leaks from chases occur right at these points. Frequency, age of roof/flashing and visual inspection of the chase top can help determine if the leak is occurring from the top, flashing or roof.
Proper chimney flashing is achieved first through continued motion and good pitch of roofing (usually we install crickets behind chimneys to divert water around back side). With pitch throughout we simply lay ice/water shield underlayment onto chimney, followed by Timberline HD roofing with aluminum apron, step and corner wrap flashings continuing onto chimney surface 4-8 inches. A final Counter flashing is than cut into chimney mortar (brick, stone and tile in some cases) and hung (from chimney) over roofing flashing. Chimney chases are wrapped with house-wrap that covers flashing and ice/water shield to form water-proof layering before façade is installed. This design utilizes the best roofing/wall flashing with an independent wall (counter) flashing allowing these opposing surfaces to move in high winds or through contraction and expansion of different seasons.
Chimney Re-pointing vs. Chimney Tuck Pointing
RE-POINTING: When a chimney leaks or to achieve our 25-year NO-LEAK Roof warranty, we recommend (INSIST with 25-year NO-LEAK) to remove mortar ½ inch deep in all brick joints along with all crown mortar. Re-crowning and re-pointing with this detail / prep work ensures thorough long lasting results (**Temps need to be 50 degrees and rising)
Tuck-Pointing: When a chimney is solid with minor cracks and holes in mortar tuck-pointing can save a customer the large expense of RE_POINTING. Tuck pointing is spot repair to the surface of existing crown and mortar without removal of all mortar and crown.
Other Common Roof Leak Situations
Click the links below to read about other common leaks that can affect your home.