Grading and Drainage
The best time to do grading is when you undertake construction of your house. It is a simple matter to ask for a few more inches between the entrance level and the ground level that will insure the easy development of a grade away from the house which will improve the appearance of your surroundings and help protect your basement from flooding. It is very important to have a inspector over see the complete project.
Anthony Perry's Inspections will make sure you do not have any problems with grading during construction. On older home we can give you ideas on how to correct any issues you may have. Grading is one of the most important issues of a home.
Rough Grading and Drainage
In lawn, garden or terrace construction rough grading is the first step. The extent of the grading depends on the condition of the ground, the desired ground levels and the attention that must be given to any extreme slopes. Adhering as closely as possible to the natural contours in grading will cut expenses considerably.
The first step is to strip and separate topsoil from the areas where the level is going to be changed. Even if the grading is for a stone or concrete terrace the topsoil should be saved for other areas that are thin or in the flower garden. Once the topsoil is stripped away, the subsoil should be graded to the desired contours, leaving sufficient space for adding the topsoil that was removed.
Be sure to plan on a slope. For lawns, a gentle slope works best, most experts recommend a minimum of six inches in slope for every 100 feet in lawn. This same guideline can be applied to stone terraces as well, to prevent pools of water in rainy weather.
Sub-Soil Drainage for Lawns and Gardens
Where the subsoil is thick or heavy clay, a drainage system should be installed. Even in sandy soil, it is a good idea, since it helps create a more even distribution of moisture throughout the lawn or garden area.
The first step in developing a drainage system is to find an area to receive the flow. A run off area is even more important if you are on low ground, on which water from higher areas flows. If you are on high ground, an underground pipe leading out over a slope will be enough.
For do-it-yourselfers, perhaps the easiest drainage run-off is the dry well. The dry well is nothing more than a pit, four to six feet in depth and diameter, filled with gravel. This area should be marked after it is covered, so that you know where it is if water starts to back up on your lawn.
Several sizes of corrugated pipe are available for subsoil drainage and should be used according to the manufacturers specifications paying attention to the minimum effective grade for effective drainage.
When back filling, put all the subsoil you have removed back in and tamp it down, if necessary. Any slight rise left after restoring topsoil will disappear after the first winter.
Measuring Your Grading
If you have a grade to level, rather than eyeballing it, use a piece of twine or string that is pulled tight between two stakes imbedded in the ground as a guide. Once you have done the rough work, use a long board as a straight edge along the ground to insure accuracy.
In leveling an area for a terrace, there is no need to add subsoil drainage. For almost all terraces, it is a good idea to tamp down the soil, and pour a quantity of gravel or crushed rock as a base. Terraces require a level area as a rule, but the grade sloping away from the house should be maintained.