Chimney Crown Cement Mix

Combine dry concrete mix water and light aggregate such as gravel or crushed rock.

Chimney crown cement mix.

Then carry the wet concrete up to the roof in buckets small enough that you can carry them. Diy chimney crown repair. This serves two purposes. The best type of cement mortar is a mixture of portland cement sand water and a small amount of lime.

Mix the wet concrete in a wheelbarrow or other large container until it has the consistency of thick pancake dough. However the types are differentiated due to the different proportion of ingredients added. Fill the form half full with concrete. A brick chimney crown made out of concrete should be at least 2 thick and have a 2 1 2 overhang recommended by the brick institute of america to protect the face of the brick wall it sits on.

And if an air entrainment agent is added it will have added resistance to weather deterioration. First without the barrier the cement will just run down the chimney structure filling the airspace between the flue and the masonry walls. The most common material used to manufacture the brick chimney crown is concrete. Portland cement to bond water to turn it into a paste sand and hydrated lime to strengthen the mix are added to the product.

The crown should be made of concrete only and mortar should not be used. Most concrete mixes i think run between 3 000 4 000 psi but i do not know what mortar mixes are designed for. The thinnest part of precast concrete crowns must be at least 2 inches. Then lay sheet metal or cement board across the metal supports to form a thin bond break between the chimney crown and the masonry walls.

The chimney crown should extend up to a minimum of 2 5 inches beyond the chimney wall and a drip edge should be provided at the bottom of the overhang part of chimney crown. If the chimney has clay flue liners the crown or top concrete material should never touch the flue liners. Chimney crowns cement chimney crown repair while the very top of your chimney may fall into the category of things that are out of sight and out of mind this oversight could be detrimental to the condition of your chimney. I show you all the steps i used chipping out the old crown cutting plywood if you are worried about moisture use 1 2 hardie bac.

The mortar mix rarely has any stones in it. The chimney crown should be made using real concrete not the mortar mix used for the brick or stone.