How to Build a Home, Step 52
Final Grade
Today we continue our series of articles that take you step-by-step through the process of building a new home. Step 52 is to establish a final grade around your dream home. By establishing a proper grade you will prevent standing water, foundation issues, and protect new landscaping. Let’s take a look at some builder tips to help you make sure your grading contractor gets it right the first time.
Schedule
The previous step in our “How to Build a Home” series was driveway paving. It’s important to get the driveway installed prior to establishing a grade as it gives the bulldozer operator a reference point. Depending on how much stone is required for the driveway, it’s elevation can change by several inches… which is enough to throw off the final grade. It may sound crazy but a grade that is off by a few inches can cause major problems (see below).
All patios and sidewalks should also be installed prior to setting the final grade for two major reasons. First, trucks will need access to these areas and if the final grading has been completed, it can be destroyed by heavy concrete trucks. This is especially true during wet, rainy weather. The second reason to have all sidewalks and patios installed before final grading is to give the grading contractor a reference point for setting the ground elevation. The contractor will also be able to back dirt up to the concrete slabs to protect the edges.
It’s also a good idea to have your surveyor out to the lot prior to final grading to set elevation stakes. These stakes will show the machine operator key elevations for establishing a positive grade that matches the plot plan. Remember, a grade that is off by just a few inches can create major problems.
Problems Created by Poorly Established Grade
In order to better understand why the final grade activity is so important, let’s take a look at some of the possible consequences of a poor job.
- Basement Leaks – One of the major causes of water in a basement is improper grading. Flat areas or grades that run back to the home are a major concern.
- Standing Water – A poorly graded lot may have standing water. This water will make it difficult to grow grass or other plants and may create a breeding ground for insects. To see what is required to correct standing, water check out this article, Water Drainage and Your Home.
- Neighbor Problems – If your final grade messes with the neighbors existing drainage, you may create problems for them. This will inevitably create problems for you in court.
- Usability – In many cases, the engineer will try to consider the use of the property when designing the plot plan. By limiting steep grades, the yard will be more usable for your family.
Engineered Plot Plan
The engineered plot plan is key for establishing a proper grade on a new lot. This plan shows the high and low points on the property and establishes a drainage plan. An experienced bulldozer operator can look at a plot plan and shape the soil to match the engineer‘s intentions.
Final Grade Quality Check
Once the final grade activity has been completed, the following items should be checked for quality.
- Swales: These should be established to allow the lot to drain properly
- Yard Drains: Grades should incorporate the yard drains so that low points are established at the drains.
- Foundation: Per the building codes, there should be a minimum fall in grade of 6 inches for the first ten feet around your home’s foundation. This will help keep your new basement or crawl space dry during heavy rain events.
- Lot lines: The grading should meet up to the existing grades on the lot lines. Because you don’t own the property adjacent to the lot line, it’s important to work within those existing grades. Your engineer takes those grades into consideration when creating the engineered plot plan. A guaranteed way to create an enemy out of your neighbors prior to move in is by allowing the dozer to run over their beautiful lawn. Need help finding your lot line? Check out this article, How to Find Property Lines.
- Protection: Bulldozers and other heavy equipment can weigh many tons so it’s important to be extremely careful near concrete and the foundation. The machine should never be operated parallel to the foundation in the over dig area…this can crack your new foundation. It’s also important to protect concrete sidewalks and curbs from those metal tracks on the bulldozer. One drive over a curb or sidewalk can cause several hundred dollars worth of damage. You should also check all other utilities for damage when the final grade activity is complete including the water stop box, storm water manholes, sewer cleanouts, foundation walls, retaining walls…etc.
Landscape Timing
You will want to have your landscaper follow right behind the grading contractor. If there is any time between the establishment of the final grade and when the ground is covered with seed or sod, there may need to be some grading touch ups. Rainwater washes the soil down into the swales when there is no grass to hold it in place. So, be sure to give your landscape contractor a copy of the engineered plot plan and hold them accountable for any drainage problems that existing when completed.
