Because the top of the chimney takes a beating from the elements over the years i recommend using type s masonry cement mortar which has an increased amount of portland cement.
What type of mortar to use for chimney cap.
Look for a specially prepared chimney mortar mix from a hardware or home improvement store and use it to fill these gaps.
If any mortar comes loose from the brick cap underneath the wash make sure that you repoint with fresh mortar.
Brick chimney crown a brick chimney crown also known as a chimney termination cap cement wash or just a chimney cap seals the chimney top opening around the flue and sheds rainwater prevents moisture from deteriorating the chimney.
Remove any mortar which is loose or has been previously used for a different chimney cap.
The first tip to remember when mixing chimney mortar is the four different types of mortar that are commonly used in building projects.
Before attempting this type of project chisel out any loose or damaged mortar to create a minimum 1 inch deep space in the remaining mortar.
This sweep said that when he does a replacement he.
The different types of mortar.
The basic mortar ingredients remain the same.
Install cap and screen at top of chimney.
It is used primarily interior above grade non load bearing walls.
You should sweep off as much of the excess mortar as you can using a hard bristled brush.
Step 1 prepare the chimney.
Portland cement to bond water to turn it into a paste sand and hydrated lime.
Mortar however is not the best material to make a chimney crown with because mortar crowns will often crack due to.
The first step is to ensure that the chimney is got ready for the cement cap.
Often masons will use leftover mortar to make the chimney crown.
Type o mortar mix has relatively low compressive strength at only about 350 psi.
I ran into a chimney sweep who explained that the reason so many caps crack is that since the mason is up there finishing the top of the chimney and he s got a batch of mortar and he s all set up to mix mortar he creates the cap out of mortar which doesn t last as well when exposed horizontally as it does when exposed vertically.
Type o can be used as an alternative to type n for some interior applications but its exterior use is limited due to its low structural capacity.
Type o mortar mix.
And to prevent rain water from entering the flue install a cap and screen at the top of the chimney.
Chimney repair projects may require a slightly different mortar mix.
Mortar typically comes as a large bag of powder that must be mixed with water per.
The chimney cap also called a rain cover is a stainless steel metal cage like box with a roof like top which fits directly on top of the chimney flue liner.
Use mortar to seal up any holes around crown.
Depending on the type of weather cap and or damper bought follow the manufacturer s instructions.
The most common use for mortar in chimneys is for mortar repair between the bricks or tuckpointing.