Erosion Under Concrete Patio

There are various reasons why voids form underneath concrete slabs.

Erosion under concrete patio.

Left unchecked erosion can wash away soil on a slope cause channels in the slope s. Bury an aluminum flashing or redwood or other suitable material a couple of inches deep and about an inch from the concrete edge allowing it to extend above the bottom edge of the concrete approximately an inch. Improper water drainage can cause the issue. Voids can lead to a weakness in the slab causing dips in the surface tilting or cracks and breaks.

Erosion the gradual loss of soil to rain wind or runoff following a rain can create havoc in a sloped yard. Roofing and gutter experts make it a point to direct water away from your foundation and other concrete structures during utah s wet season the outpouring can easily wash away supportive soil from around your walkway driveway patio and foundation. While erosion is a commonly cited culprit there are also naturally occurring reasons for the presence of voids under slab foundations. Some nasty runoff eroded a cavity under the edge of my concrete patio and i became concerned about the lack of bearing along its edge.

Shrub and tree roots excel in preventing erosion way better than grass roots. Let s say that it s already too late to install some preventative measures or that you did. How to prevent soil erosion around a patio erosion causes. So what should you do if you notice erosion around or under your concrete slabs.

Concrete slabs can develop voids from a variety of reasons ranging from sliding soil beneath the slab displaced because of a lack of proper compression to water erosion slowly washing away the soil over time. To remedy the situation i used the apparatus shown in the drawing to pack mortar into the cavity. Many people will attempt to fill these voids with dirt sand or gravel and while something is better than nothing none of these solutions are able to generate any upward pressure on the concrete so not much support is possible. Steps to control patio soil erosion take preemptive preventative measures.

Another issue that could cause erosion under concrete is a burst water pipe. If the pipe is beneath the concrete the structure will no longer have firm dry soil underneath it just mud. Sooner or later the slab would break off where the soil had been washed away. Indeed the best way to address soil erosion is to try and prevent it from ever.

An unusual amount of cracking spread over a large area isn t normal however and usually indicates that the slab is sinking. If soil from around your patio washes down a hill then hardscaping will help keep it in place. In fact most slabs are constructed with control joints along which cracks are supposed to occur. Add ground cover.

Depending on its construction a patio is either of limited porosity or not porous at all.