EXPANSION CONTROL JOINTS
Expansion control joints are vertical seams in brick work. The purpose of an expansion control joint is to create an intended weak spot within the wall. This allows energy from the expansion and contraction of the soil to pass through the brick work, vertically, without cracking the brick and mortar.
The energy that’s released from the movement of the soil will always take the path of least resistance. In brick work, this is a straight line. Therefore, the expansion control joint is a straight, vertical line where two brick panel sections meet. With the requirements of the ASTM building code, an expansion control joint must be installed every 20 feet, linear. For example, if a wall on your home was 60 feet long, it should have two expansion control joints along that wall, dividing the wall into three, equal 20-foot sections. By following these requirements, it allows energy to be effectively released.
The secondary purpose for the expansion control joint is that if damage does occur within the brick, it would be limited to that panel. Any horizontal fracturing would stop at the expansion control joint since the two panels are not connected to each other.
Expansion control joints can be filled with mortar or caulking, each having their own benefits. Often, we hear people proclaim that an expansion control joint can only be filled with caulk. Their belief is that the house is swelling and the caulking will stretch with that swell. This is incorrect. The sole purpose of the expansion control joint is to crack so other things don’t. Therefore, no matter what material you put in an expansion control joint, it will crack.
Because the expansion control joint is approximately a half an inch wide, we normally install mortar, initially, because a half an inch (in width) of caulking will sag out as you’re installing it, and it has a tendency to break down in UV light from the sun and shrink, causing an ugly opening on the side of your home. Later, once the mortar in the expansion control joint develops a hair line fracture, the home owner can install a thin bead of caulk along the seam, creating easy maintenance for the home owner.
Most homes have inadequate expansion control; however, this is easily remedied. Advantage Masonry can install expansion control joints on pre-existing homes. In fact, expansion control joints are added on nearly every home that Advantage Masonry repairs. By doing this, it significantly reduces the likelihood of future cracking once the home has been repaired. Simply put, nature won’t change its laws because a home is built on a certain property type. Instead, the home must have adaptations to allow nature to act upon the home without destroying it. Expansion control joints are not very expensive to install, but they will save a fortune on future maintenance.
NOTE: If you would like to schedule a free, no obligation inspection by one of our qualified technicians to see how your home could benefit from adequate expansion control, please click on the link below.