How to Rebuild a Crumbling Chimney Crown
The chimney crown is the top most part of your chimney made out of concrete. It protects other integral and essential components of your chimney including bricks, joints, fireplace and mortar, helping you gain maximum benefits possible from your chimney. If you notice cracks or crumbling, follow the steps below to effectively repair and rebuild your chimney crown.
Step 1: Remove the Old Chimney Crown
To begin, cover your roof by placing drop cloth over to protect it as you work. Then remove the old or previously installed chimney crown by breaking away the concrete around it with a chisel and hammer. Starting in one corner is a good idea, and it is recommended that you work cautiously and gently so as not to strike around the flue of your chimney. Collect the scraped pieces in a bucket.
Step 2: Create Your Blend
Make a dry mixture of masonry cement with half a bag of pea gravel. Ensure that your blend is uniform throughout before you add water. Now, place the new crown into your wheelbarrow, adding it to the mixture. Add some water every now and then, minding the consistency. When you are about to reach your targeted or desired thickness, pour a single cup of bonding agent into the mixture and blend it thoroughly.
Step 3: Add Cement
Put some of the cement mixture in a bucket and carry it to your roof. Dig out your cement with a trowel and consistently pour it out over your chimney, covering the complete flue. Once done, chop off the cement using the corner of your trowel.
Step 4: Place the Crown
Determine whether your flue sticks out less or more than 6 inches in total. If it sticks out more than 6 inches, form your chimney crown about 4 inches higher than where it connects to the flue. If it sticks lesser than that, build the crown exactly 2 inches from the flue’s top.
Finally, use your trowel to create the shape of a pyramid sloping away from your flue. Make sure the flue becomes the center of your chimney crown and apply the cement around it, smoothing away any irregularities Lastly, apply a water sealant to your chimney to complete the project.