How to Seal Your Chimney Cap

What You'll Need
Non-flammable material, such as refractory cement
Broom or brush
Safety glasses
Protective overalls and working gloves

gular inspection of the flue helps to maintain its good condition, the chimney cap or any other part can easily be identified and repaired. It is an effective method of enhancing the safety of the fireplace and making sure that is works effectively to conserve energy. Damage on chimney caps affects the efficiency of smoke leaving the chamber. This can easily leak back into the house and cause an unpleasant atmosphere.

Step 1 - Clean the Chimney

Put on safety glasses, working gloves and overalls. Use a broom to clean the inside of the chimney. Cover the front of the fireplace with suitable material so as to keep the house clean. Gently brush the inside of the fireplace to get rid of creosote or the black particles that remain after burning fuel.

If you are fit then prop the ladder in the chimney so as to clean the entire place as well. Be very careful when doing this. Make sure that the ladder is securely placed against the wall. Ask for assistance from a mature person to keep the ladder in place.

After cleaning the entire surface of the chimney, remove the debris and dirt and dispose them appropriately.

Step 2 – Inspect Chimney Cap

Use the flashlight to check the surface of the chimney for any cracks or gaps. If it is made of clay or brick, check if there are missing or broken pieces. For chimneys made from metals, look for holes that could have been caused by rust or corrosive elements.

Step 3 - Seal Chimney Cap

If there are spaces, joints or openings on chimney cap, use non-flammable material to seal it off. For best results, buy high refractory cement from a hardware store and confirm with the store attendants that the product is fire-resistant.

For gaps located on chimney cap, seal the areas using bricks or clay blocks. This is applicable for chimneys made from clay or brick. Use refractory cement to secure them in place. Use the cement to seal other joints that are poorly done.

Step 4 - Inspect the Entire Chimney

Check if there are other gaps or spaces within the chimney as well. Common problems occur at the flue’s opening and the fireplace or stove. If there are gaps in the chimney are as a result of the damper, correct the fault by securing it in place. Make sure it is fast enough to prevent any more leakages. This can help to conserve heat when the fireplace is on. For leakages or gaps on the surface of the chimney, use refractory cement to seal them off.

Leave the chimney to dry for about 2 days after carrying out the repair job. Do not light a fire as it might affect how well the seal on the chimney cap dries.


  • Only use high temperature or refractory cement to seal gaps in the chimney
  • Do not burn wet wood or pellets in the chimney as they emit harmful gases
  • Inspect chimneys regularly to keep them working in good condition. It helps to save energy and prevents harmful gases from leaking into the house