We have yet another obstacle to work around...sinkholes. All of a sudden a hole can open up in the yard, or under the house. My neighbor woke up one morning and the 12 foot shrub outside his front window was only two feet tall; no pruning required. When it is around the house, they come in and inject concrete into the ground. Sometimes it takes a hundred trucks worth of concrete to do the job and then it is not guaranteed. There are stories of entire houses falling into them and streets are often closed for sinkhole repair. Concrete patios and driveways are subject to cracking thanks to the unstable ground. That's why I am going with pavers on the new lanai.
Jim
