Do you need control joints in stamped concrete?
As with any concrete surface, your most obvious way to control cracks is to cut control joints. They reduce the risk of random cracking by forcing the concrete to crack in vulnerable areas. Early-entry cutting will work with stamped concrete too, but with one big complication.
How often do you need control joints in brick?
Normally, horizontal control joints are placed every floor over the windows. However, they could also be placed at every floor line with loose lintels over the windows. The control joint could be spaced every two floors, however, the size of the shelf angle and the width of the joint would have to be larger.
Where are brick control joints placed?
Place expansion joints near corners to alleviate this stress. The best location is at the first head joint on either side of the corner; however, this may not be aesthetically pleasing. Masons can typically reach about 2 ft (600 mm) around the corner from the face where they are working.
How often do you need control joints in concrete?
Usually, expansion joints should be no farther apart than 2 to 3 times (in feet) the total width of the concrete (in inches).
What is the difference between control joint and expansion joint?
In building materials, a control joint is used to control cracking while an expansion joint is designed to handle structural movement. A control joint can be formed during placement of the building material or cut after the material is placed.
How do you keep stamped concrete from cracking?
Maintain moisture levels after pouring: A great way to prevent cracks is to keep the concrete damp for five to seven days afterwards to ensure that the concrete cures completely. This can be done by using a hose and then placing a cover on top that is held down by heavy objects, like stones or bricks.
How often do bricks need expansion joints?
With respect to horizontal expansion joints for vertical movement the outer leaf should be supported at intervals of not more than every third storey or every 9 metres whichever is less.
Is it too late to cut control joints?
WHEN TO SAW CONTROL JOINTS Cutting freshly poured concrete too late can lead to unwanted cracks in the concrete, rendering the joints ineffective. For most concrete work, cutting should take place within the first 6 to 18 hours and never beyond 24 hours.
What is the difference between expansion joints and control joints?
How deep do you cut control joints in concrete?
Cut joints 25% of the depth of the slab. A 4″ thick slab should have joints 1″ deep. Groover tools cut joints in fresh concrete. Saw cutting cuts joints as soon as the concrete is hard enough that the edges abutting the cut don’t chip from the saw blade.
What is a masonry control joint?
Control joints in masonry are vertical weak planes intentionally built or cut into masonry to control where cracking occurs. Control joints should be installed in any masonry assembly that expected to experience net shrinkage over time. Usually, we think of control joints in concrete masonry (CMU).
How do you fix hairline cracks in stamped concrete?
I recommend wetting color patch materials with a 50:50 blend of concrete bonding polymer and water. Use a wooden tongue depressor or gloved finger to smear the color patch into the cracks. Soften the edges with a damp rag or sponge to blend the patch and color into the slab. Let these repairs cure for 24 hours.
Where does a control joint stop on a brick wall?
(Right) View of a control joint in a concrete brick veneer where the control joint stops at a soldier course above a window lintel, leading to cracking at the soldier course. Another common control joint problem is stopping control joints short of the bottom of a wall or the top of a window/door opening (Figure 4).
What are the different types of movement joints used in brick construction?
The primary type of movement joint used in brick construction is the expansion joint. Other types of movement joints in buildings that may be needed include control joints, building expansion joints and construction joints. Each of these is designed to perform a specific task, and they should not be used interchangeably.
When are control joints required in concrete masonry?
Control joints are typically required in exposed above grade concrete masonry walls, where net aesthetic shrinkage cracking may detract from the appearance of the wall, and to limit moisture or air infiltration. Shrinkage cracks in concrete masonry are not a structural concern.
What are common control joint errors in concrete brick veneer?
View of concrete brick veneer showing control joint locations (indicated with green lines) and shrinkage cracking (indicated with dashed yellow line). This veneer did not contain bed joint reinforcing. Another common control joint error is the omission of bed joint reinforcing and/or control joints in concrete masonry veneer (Figure 5).