Grading in landscape architectural construction is the work of ensuring a level base, or one with a specified slope. For a construction work such as a foundation or landscape and garden improvements — the earthworks created for such a purpose are often called the sub-grade or finished contouring. In simpler terms, the grade around your house is the level of the ground. The ground level and how it’s graded is the deciding factor of where storm water will flow.
There are two types of grading — positive and negative. As you might gather; a positive grade is good, a negative grade is bad. Positive grading slopes away from your home, directing storm water away from your foundation. Negative grading slopes toward your home, directing storm water toward your foundation. When storm water consistently collects near the home only bad things can happen — that is why negative grading needs to be corrected as soon as it’s discovered.
First of all, individuals who are buying a home should have a home inspection prior to purchase. Checking for grading issues will be one of the things your inspector will do — he will look for visual signs of negative grading. If the ground is extremely dry, the evaluation on inspection day may not reveal all conditions. Most home buyers will make changes to landscaping, like putting in flower beds so they should pay careful attention to any grade issues. Upon moving in and as part of regular home maintenance, homeowners should review gutters, downspouts and grading after heavy rains — this is the perfect time to notice where storm water flows and if water is collecting near the home, then the grade should be corrected.
Observing the home is very important because looks can be deceiving — even beautifully maintained home exteriors with mulched beds and seemingly perfect landscaping could contain improper grading that could be damaging the home. Every homeowner must take the time to watch and see where the water goes as it flows around your property.
A negative grade can be repaired and it can be done fairly cheaply. It can be as simple as shovelling soil toward your house or bringing in soil from another part of your property — be careful not to cover your existing siding. If you must add soil from an exterior source, use top soil or it’s sometimes referred to as black dirt or grading soil. These soils will keep much of the water at grade level until it has a chance to move away or toward your house. Do not use sand, because water flows through sand very easily and can make a bad grading situation even worse. In order to divert water away from the walls of the house, the soil must be dense and must slope away from the house.