Chimney Seal – re-grouting or waterproofing?

Chimneys need waterproofing, sealing or re-grouting over time

Flat roof leak caused by chimneys
Flat Roof Leaks caused by chimneys

All chimneys need waterproofing or sealing over time. Sealing the crown and flashing will generally fix the chimney leak. The crown consists typically of a cement slab on top of the chimney that cracks and separates from the rest of the chimney. The flashing is the metal at the bottom that loosens up from the mortar and causes leaks.

Waterproof the cap or crown of a chimney. This will help save the chimney from leaking

Watch this video to see where to look for issues on a chimney and how to seal or waterproof a cracked chimney.

It is good to have someone check the chimney every 5 years for defects.

Use the following checklist for a chimney repair and inspection

  1. Flu pipes – Those square or rectangular clay pipes that go down the middle of the chimney. It so happens that many times they disintegrate due to ice build-up around them during winter.
  2. Crown – that the cement slab on top of the stone or bricks surrounding the flue pipes. That is almost the first thing that will go wrong on a chimney. When a mason pours that cement slab, it’s not well reinforced. Therefore they crack over time and let water into the chimney. The best is to remove that cement and replace it with concrete.
  3. Bricks or Stone face – Very often the grout will be falling out from between the bricks or stone. That’s when the old grout needs to be removed and replaced with new grout. – Chimney pointing. So often people will just use caulking to seal the cracks around the stone or bricks.
  4. Flashing – That is the most critical part to keep water from leaking into the roof. Counter flashing is above the flashing. The counter flashing has a small lip bend to fit into a groove, and this is where most chimneys have issues. The material that most mason’s use to secure the flashing is cement. When that cement is of poor quality or not mixed correctly, it will become brittle and fall out, causing a leak.

Over the years chimneys need some maintenance. Most of the time the crown on top will have to be sealed. The flashing at the bottom also separates and causes leaks.

The best is to remove all loose cement and re-point the chimney. We use grinders and pneumatic hammers to remove old cement grout.

Chimney repairs - Over the years chimneys need some maintenance
Repointing a chimney with grout cement

We replaced the flashing with a new copper flashing. The flashing is the heart of all chimneys and roofs. If not done correctly, it will leak.

chimney repair - It is important that the flashing is well seated into the brick or stone. We serve all of Fairfield county.
Removing the flashing skirt to get to the flashing

It is common for a chimney to be the cause of a leak. Most of the time it will be the flashing that is not well sealed. You can see the black marks on the flashing and know how many times people attempted to repair this flashing on the chimney. Removing of old tar was necessary.

It is common for a chimney to be the cause of a leak.
Notice the brown streaks on the chimney. that is water was leaking in

The flashing around the chimney is the most important part. When that is compromised then the chances of a leak is bigger.

You can see new copper flashing that is longer than the old one.

The flashing around the chimney is the most important part.
Notice there is no cement slab on the crown

Most of the time the existing flashing on a chimney can be reused. In this case, we had to make new flashing. The copper flashing extends further from the chimney and now covers the ridge area.

Most of the time the existing flashing on a chimney can be reused.
New flashing made that will reach over the top of the roof

After installing the new flashing, the counter flashing is re-installed. The best way to secure it is with cement. The skirt flashing was re-installed.

After the new flashing is installed, the counter flashing is re installed.
New flashing being fitted

The counter flashing is put back. It is important to secure the area where the flashing is attached to the chimney. Cement is used to seal that from water getting in. We removed the crown that was loose and cleaned it. When a crown goes bad, the rest of the chimney starts to fall apart due to ice.

The counter flashing is put back.
After installing the flashing, the skirt flashing is placed back

The body of the chimney, in this case, the bricks have to be re-grouted. The flashing is also grouted in to make for a secure seal.
The preparation of fixing a chimney is what takes time.

The body of the chimney, in this case the bricks have to be re grouted. The flashing is also grouted in to make for a secure seal.
Repointing or grouting. Over the years the cement grout will come out

After removing the loose cement, new grout is mixed, and the chimney is re-pointed. After the flashing, we then Installed fresh cement on the crown.

After removing the loose cement, new grout is mixed and the chimney is repointed.
New Chimney grouting making a good seal

One of the areas that start leaking is the cement slab on top. We removed the old cement and is preparing for a new cement crown. The flashing is sealed, and the pointing is new again.

One of the areas that starts leaking is the cement slab on top. We removed the old cement and is preparing for a new cement crown.
Preparing the crown for a new cement slab

Most of the time chimneys need maintenance. It is essential to remove the old grout and repoint the chimney with new cement grout. This is what the final chimney looks like. The owner himself can do something like this. Lol maybe not.

Most of the time chimneys need maintenance.
Flashing is now sealed with fresh cement grout

The chimney repair is complete. Flashing is secure, the grout is fresh, and the crown is new. We also installed a stainless flue cap to keep squirrels out.

The chimney repair is complete.
Job well done
It is not important but if you wish a flu cover can be installed
The last thing to install is the Stainless Steel flu cap
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