Ever wonder how a driveway can push a house? This article explains what street creep is, how to detect it, and how to prevent it.
What Is Street Creep?
As a home inspector, I find evidence of street creep about 3-4 times a month on newer and existing homes. This occurs when the street has pushed the concrete driveway into the garage floor causing movement. Sometimes the movement can be minor causing hairline cracks in the garage floor and foundation wall, while other times the force has caused major buckling of either the driveway and the garage floor as well as pushed the foundation wall significantly out of alignment impacting its structural integrity. If a driveway is lacking properly installed expansion joints, then having a licensed contractor install a few expansion joints before the movement occurs can save homeowners thousands in repairs
down the road.
Characteristics of Concrete in relation to street creep
1. Concrete flows downhill
2. Concrete expands and contracts in cold winter months
Where can you find driveway creep?
The worst-case scenarios of driveway creep are found on houses with driveways on the downhill side of the curve in a street, at the bottom of a circle, or a house that is unfortunately located at the downhill end of a street that T’s into another. These scenarios will bare the brunt of most of the force of the movement, as the concrete naturally wants to shift downhill. I’ve also seen less serious instances of street creep commonly on homes that simply have inadequate expansion joints or lack expansion joints regardless of where they are situated in regards to the street. Street creep is not found on gravel driveways or asphalt driveways, but is found on concrete driveways covered over with asphalt.
How to prevent street creep
First, check for expansion joints. Expansion joints are supposed to be located between the street and the driveway, between the driveway and the garage floor, and between the driveway and any steps or sidewalks running off of the driveway. Expansion joints usually have felt paper ½”- ¾” in width. Take a screwdriver and push it downward into the expansion joint beyond 4” (as this is supposed to be the minimum thickness of your driveway) and if you’re successful, then you have a properly installed expansion joint. If the screwdriver hits concrete, then the expansion joint doesn’t properly go all the way through and won’t protect your driveway, garage floor, or home from future movement. Sometimes the
expansion joints have been squeezed and now have concrete touching concrete. Second, if you’ve determined that your driveway is lacking expansion joints or the expansion joints are inadequate, then you need to hire a licensed contractor to properly install the expansion joints. This
normally will cost only a couple hundred dollars to have a professional saw cut the concrete and install the felt paper or backer-rod with expandable caulk.