We inspected a newly built home and there were no expansion joints installed in the driveway or the sidewalk. The sidewalk joins to the driveway and has no expansion joint at this junction. There were no cracks as of yet. This doesn’t appear to be a proper installation to me. Does anyone have any comments?
Picture of sidewalk and (not so close driveway) attached
That house appears to have no slope away from the foundation, as well as no gutters/downspouts. The lack of slope is a problem that I know of no way to satisfactorily address. It would have been so easy to grade the site 6" higher at the beginning, just as it would have been easy to put in those expansion joints when pouring the walk and drive.
Something similar to this is what should have been done.
Crack Control Joints (Dummy Joints)
This type of joint is most commonly encountered on Pattern Imprinted Concrete paving, particularly residential driveways and patios.
For creation during construction, the control joints may be pre-formed using a timber strip and/or a Grooving Trowel. The inclusion of a crack inducer will help ensure cracking takes place in exactly the right place. Depending on the type of joint required, additional work may be necessary once the concrete has cured. If a timber or other temporary former has been used to create the wet-formed joint, it should be removed and the joint sealed with a suitable sealant, usually a polysulphide such as Thioflex.
Wet-formed crack control joint Sawn joints are normally cut a week or more after sealing, so that the concrete will have had a reasonable amount of time to cure and avoid ‘spalling’ at the cut edges, and for the sealant to protect the surface from the concrete dust. On no account should concrete dust be allowed to rest on the surface for any length of time as it will set and could damage the surface when forcibly removed. They are cut into the cured pavement using a power saw with diamond-blade, and should be between 25% and 33% of the depth of the slab. A trolley-mounted floor saw will ensure a neat and true cut is made; hand-held cut-off saws have a tendency to ‘wobble’ during the cutting operation, giving a cut with all the straightness of a dog’s back leg. If a hand-held cut-off saw is the only option, a suitable guide rail should be used to keep the cut straight and true.
Exactly. Cuts and grooves control (limiting how far a crack that may form can go) cracks. The expansion joint provides a place that is flexible allowing the concrete to expand and contract with temperature…in all directions.
Remember too, concrete shrinks when it cures. Improper preparation can cause the concrete to knit to blocks, bricks, etc. causing them to pull loose as the concrete cures.