You start the foundation with a footer or footing.
Joing new concrete wall to older one.
Over time this expansion and contraction especially if they occur at different rates due to the sections of concrete being exposed to different temperatures will work the sections apart and the crack will widen.
The intend of the dowels are to pull together the old and new concrete together such that their bonding become inseparable.
This footing will soon have a foundation wall on it directly over the keyway groove in the concrete.
Dump out all of the concrete onto the old concrete and spread it out with a hand trowel or a paver to form an even layer.
Even some require application of bonding agent to enhance the bonding.
Both walls are 8ft high 10in width.
Connect new foundation to existing.
After you ve brushed your slurry mixture onto the old concrete you can apply the new concrete that you mixed.
You can join the new concrete right to the old concrete this is called a concrete construction joint.
Those two pieces of vertical rebar help lock two different pours of concrete together.
I imagine it requires grouted pins.
Some engineers require the edges of the existing footings and foundations where the new and old concrete meet be roughened.
What is standard practice for joining a new poured concrete wall to an old poured concrete wall.
The new wall must sit on the same level foundation as the old wall.
The edge of the existing concrete that was sawed should be drilled and doweled so the new concrete won t separate lift or settle from the old concrete.
Pour the new concrete on top of the old concrete.
Make sure the braces are level and lay down a barrier of wire mesh over the existing concrete inside of the barrier.
To lay new concrete sweep and clean the old concrete and saturate the old concrete with water.
Where no foundations exist the new wall will not be on solid footings and will sag or crack.
A single wall no higher than 1 8 metres requires a 300mm deep x 300mm wide footing while a double wall or a wall higher than 1 8 metres should be 600mm deep x 300mm.