What is a raked brick joint?
In raked joints, the mortar is not compact against the surfaces of the joint. Instead, the front portion of the mortar joint is scraped out. Raking the mortar out can open up voids in the head and bed joints that increase water penetration.
How do you make a raked mortar joint?
Insert the nail head on the rake you made into a vertical joint. Pull the board straight down to created a raked joint. Remove any mortar you pull away from the joint. Repeat this process for all the vertical joints, and then move the rake from side to side do all the horizontal joints.
How often do you need a control joint in CMU?
The National Concrete Masonry Association (NCMA TEK 10-2C) recommends that control joints be spaced at 25 feet or 1.5 times the height of the wall, whichever is less.
Why are the joints in a concrete block wall tooled?
Proper tooling increases resistance to water penetration along the wall. The “jointer” tool compresses the mortar against the unit, helping seal any separation cracks that might form at the interface. The action of the jointer on the unset mortar brings the concrete fines in the mortar to the surface.
What is a raked joint used for?
Raked mortar joints Ledges collect water as it runs down the wall allowing it to pool and enter the brickwork. Additional voids may open up, increasing the possibility of water penetration.
How deep is a raked joint?
2.06 It is vitally important that the joint is raked out properly to its full height and full depth. The depth for raking out for repointing should be between 15mm, absolute minimum, to 25mm.
How deep should you rake out of mortar?
To repoint mortar joints, the old mortar must first be removed, generally to a depth of at least 15 mm, but often much deeper (more on this later). This removal of old mortar is generally referred to as raking out.
Why raking of joints is done?
Raked joint This creates more shadow between the joint and the brick and gives a very well-cared-for appearance. Can be done smooth or brushed.
What tooled joints?
Definition of tooled joint : a masonry joint in which the mortar is compressed and given a concave or V shape with a jointing tool while the mortar is still green.
Why raked joints are not advisable to use for an exterior wall construction?
Raked Joint: The raked joint is another joint not recommended for exterior use because its ledge may allow water/snow/ice to sit on top of the brick.