What is Grading
Rough grading is what sets the slope of the yard. In most areas the soil is primarily clay base and is at times naturally mixed with sand and or stone.
Rough grade and backfill material should never be mixed with organic material. Organic material is permeable and grade water will flow through it quickly. Where as with good clay, water seals the clay as it permeates blocking off the flow of water.
Finish Grading is done by putting an even layer of topsoil over the rough graded clay. This allows the yard to have a lawn and allow rain water to percolate down to the clay and travel away from a properly grade building.
As the backfill of the home or business settles the rough grade and finish grade sink, many of our client have put decorative stone or additional topsoil in to fill the void.
By doing this a fish bowl has been created below the level of the lawn. As the backfill settled, it create a negative slope that allows water to sit or travel towards the structure.
What is Re-Grading
Re-grading requires that the topsoil be removed in the failed area and the appropriate back fill be installed before replacing the topsoil.
This is standard procedure that is overlooked by many.
The logic behind this process may seem obvious once a person has been informed to how differing soils react to water.
Failing grade doesn’t happen in the open areas only, under slabs, patio, decks where many people hid their leaf pile, or in good faith mud jack with a slurry of sand and now modern foams.
The problem with these products are that the sand slurry, even with a cement binder allows water to flow through it. The foam fills the void but does nothing to stop the water from traveling between it and the original gravel or sand base that may have held and was the base for the driveway or patio.
Determining Grading
When determining what to do with a water problem, your first consideration is that you do not want your problem to become someone else’s.
The best solution is to follow what was originally set as an original grade. That may not seem obvious. Typically the property slopes to the front or back or a combination of both including a swale.
On occasions in small communities and older areas of the city, grade programs were never established or the grades of roads and alleys have been raised leaving your home below the level of the street. This is more common than you would think.