Waterproofing, Crown Rebuilding & Sealing

Water damages chimneys more than any other single factor.

Water penetration through cracked crowns, missing rain caps, blowing rain, or other causes leach lime out of the mortar and turn it back into sand. Freeze-thaw cycles with water in the masonry may crack the flue and cause spalling.

Chimney saver products stop water penetration and have a ten year warranty. Don't use products such as Thompson's sealer or paint on your chimney. They will trap moisture in the masonry and will accelerate damage from water to your chimney rather than prevent it. Besides, the life of Thompson's sealant is less than a year in many climates. Chimney Saver protection adds long life to your masonry. 

Waterproofing

Protective coatings can reduce the amount of water that is allowed to enter your chimney. Bricks are porous and once they are worn they will allow water to penetrate deep into and even through the chimney.

Water, left unchecked may cause deterioration, corrosion, spalling, and efflorescence, (see below). This will result in long-term damage to your chimney and ultimately water can cause complete failure of the chimney. Masonry chimneys should be treated in order to prolong their useful life. The cost of treatment is far less than treating the problems that may arise if water gets in.

Evidence of Water Penetration

	Efflorescence - The white stains on the outside of a masonry chimney indicate that water has penetrated the brick and salts are pouring out of the chimney.
	Spalling - Water entering the brick, saturating it and then freezing and thawing will separate the facing from the bricks and pieces of brick will fall off of the chimney. This is a very serious problem and should be addressed as soon as you notice any problems.
	Erosion - Bricks just begin weakening and falling apart along with the mortar that should be holding your chimney together. Again the culprit is moisture, wind and rain combined with harsh temperature changes that occur seasonally.

 

Cracked chimney crown in need of repair

Chimney crown after successful waterproofing efforts

Crown Repair

The crown is the very top of the masonry chimney which slopes away from the flue to drain water away. Deteriorated crowns let water into the masonry. This may leach the lime out of the mortar - lime is what holds it together - and it turns back into sand and runs out of the joint. The resulting gap is literally a hole in the flue. When can fix it however it is cheaper and easier to make sure the crown is sealed. Crown seal products keep the water on the outside where it belongs.

Your chimney crown is the area that is around the top of the chimney. It tops the masonry walls of the chimney, usually with a wider masonry or cement area. This solid covering stops moisture from filtering down through your brick or stone work. It protects the mortar that holds everything together.

There are chimney crown sealants that are able to be applied to a chimney crown that still has structural integrity, but needs to be waterproofed. Larger cracks are filled with high bond patching material and then Crown Sealing in applied over the top of the whole chimney crown. The sealant forms a waterproof membrane between the elements and your chimney. When properly applied these solutions can add up to 15 years to the life of a chimney crown that has begun to wear.

 

Flashing

The flashing keeps water from running down the outside of your chimney and into the house. Enough said. We are good at making sure that this does not happen.

Leaks present real problems for your home. The most common place for leaks is where the chimney meets the roof. The area surrounding the chimney as it goes through the roof needs to be sealed with flashing so no moisture enters your roofing, attic or ceiling areas.

Torn, loose and missing chimney flashing can cause tremendous structural damage to your home including wood rot, mold and drywall damage. If you have any leaks at all around your chimney please allow us to do an inspection and make the proper repairs. Many times when leaks begin you won't even know it because the damage starts in areas that you don't see. A trip to the attic to inspect the area surrounding the chimney as it enters the roof may be a good preventative measure.

How does Chimney Flashing work?
Overlapping sections of metal that are custom fabricated to fit around your chimney at the roof line are called "Chimney Flashing". Flashing is installed in two layers and is fitted under the roof covering or shingles and then up along the wall of the chimney. Urethane caulking is used to create the water-tight bond needed to protect against damage. Chimney Flashing can be made of aluminum, stainless steel or copper, the longest lasting material.

 

* Link to Chimney Saver »