One critical aspect homeowners often overlook when making plans for a new swimming pool installation is the nature of the ground beneath the pool. In South Florida, many municipalities have building codes that mandate a geotechnical analysis, commonly known as a “soil report”, for new swimming pool construction. In this article, we explain what’s in it and whether, why and how you should get yours.
What’s in a Soil Report?
A typical soil report for a swimming pool building project contains the following elements:
- Soil composition. South Florida features a variety of soil types due to its unique climate, geology, and environmental conditions. The soil in your property may be sandy, rocky, organic or clayey, for example. Most likely, we’ll find different soil types at different depths. Depending on the soil, different swimming pool engineering and construction approaches may be necessary to ensure the stability and durability of your pool. The soil report will tell us, your pool builder, what type of soil we’ll find in your property at different depths, all the way down to 20 feet or deeper.
- Load-bearing capacity. The soil report describes the soil’s ability to bear the weight of the pool, including the water, structure, and any additional loads. This is important to avoid settling, which can lead to structural damage or failure.
- Water table level. The report provides the level of the water table and drainage considerations. High water tables or poor drainage can cause hydrostatic pressure, leading to potential issues like “pool popping” or cracking. Also, if the water level is such that the pool hole will be partially filled with water as we excavate, we will need to set up a dewatering operation. These are crucial considerations in the engineering design and construction of your pool.
- Recommendations. Based on the soil test results, the geotechnical report will recommend specific construction techniques, such as over-excavating and replacing unsuitable soils, using geogrids, or designing special foundations like piles.
Do I Need a Soil Report for My New Swimming Pool Project?
You will definitely need a soil report if your property is located near a large body of water or swamp area; in a flood zone; in areas with high water tables or poor drainage; in areas known to have soil with highly decomposed organic matter (“muck”); and in municipalities where a soil report is mandatory when applying for a new swimming pool building permit.
Even if a soil report is not mandatory in your case, it is still a wise consideration in scenarios where there are uncertainties about the soil conditions or where the risk of future problems could outweigh the cost of the report. Also, without a soil report, the price any pool builder in South Florida will give you is essentially a preliminary estimate, subject to increases depending on the soil conditions.
Unless you don’t mind being surprised by an unbudgeted increase ranging from $5,000 to $20,000 or more in the total cost of your pool, you should order a geotechnical report in advance.
Pool Price Implications
In general, when a pool builder in South Florida provides you with a new pool estimate without a soil report in hand, they are basing their estimate on firm, dry soil. We may occasionally find firm, dry soil during excavation in Coral Gables and parts of Miami, but that’s not the usual case in Miami-Dade, Broward and Palm Beach counties.
More often that not, we find the soil to be either sandy or to contain some sections of highly decomposed organic matter (“muck”). It is also common to find groundwater at a depth of 4 to 5 feet.
These are the potential price implications from these findings:
- Shoring. In areas with loose, sandy, or wet soils, shoring is required to prevent the sides of the pool excavation from falling in, which could otherwise cause injury to workers or damage to the pool forms.
- De-mucking. The soil report will let us know whether we’ll find “muck” as we excavate. Any excavated muck must be trucked away from the jobsite, as it cannot be used for backfilling. Differently from clean dirt and sand, which are desirable and easy to dispose of, few disposal sites accept muck, and the ones that do demand higher fees due to the extra care needed to manage this type of waste.
- Dewatering. In pool construction, dewatering is crucial when the water table is high or when the soil becomes saturated with water, which can compromise excavation, construction, and structural integrity. The soil report provides guidance regarding the expected water table level. Pool builders incur extra costs, often substantial, in setting up a dewatering operation.
- Piles. If the load-bearing capacity of the soil is found not to be adequate for a swimming pool, the soil engineer will recommend the installation of piles to build what’s called a “deep foundation”. Piles are long, sturdy poles or columns made of steel or concrete that are driven deep into the ground to provide extra support for the pool. A deep foundation using piles typically add $5,000 to $10,000 to the cost of a pool.
All pool builders in South Florida have provisions in their contracts which exclude extra costs resulting from excessive dewatering, de-mucking, shoring construction and deep foundation requirements that could not have been anticipated without a soil report. Many pool contractors will not bring up the need for a soil report until it surfaces during the permitting process. Unless you don’t mind being surprised by an unbudgeted increase ranging from $5,000 to $20,000 or more in the total cost of your pool, you should order a geotechnical report in advance.
Firm Pricing
We’ll be more than happy to provide you with a preliminary quote based on the standard assumption of firm, dry soil. With a soil report in hands, we’ll be able to provide you with a firm quote to design and build your new pool, thus avoiding price surprises that may turn out to be quite unpleasant.
How Do I Get A Soil Report and How Much Does it Cost?
For pool building permitting purposes in Florida, the soil report must be prepared by a geotechnical engineer or geotechnical engineering firm.
Technicians will come to your property to collect soil samples from various depths using drilling rigs or hand augers. They will need access to your pool location and enough clearance to bring in the rigs. Collected soil samples are analyzed in a lab. The data gathered from site investigations and laboratory tests are then compiled into a comprehensive report by a soil engineer. The soil report includes the geotechnical engineer’s recommendation regarding the types of foundation we should consider for your swimming pool.
AQUAVIX Pools works with several reputable geotechnical engineering firms in South Florida. Here are a few that have been doing excellent work for us and our pool customers:
- Federal Engineering & Testing Inc.
- Dynatech Engineering Corporation
- Nelco Testing & Engineering Services, Inc.
Geotechnical engineering firms in South Florida typically charge somewhere around $1,000 to $1,500 for a soil report for residential swimming pool construction. The price varies from company to company and depends primarily on property location, accessibility and number of boreholes required. It typically takes 1-2 weeks to schedule a testing appointment.
AQUAVIX Pools can provide you with a soil report from one of these firms for a flat fee of $1,200. Most of our customers find this to be a convenient and economical option, but that’s entirely up to you. If you prefer, you can contact these firms directly, request quotes, schedule testing and pay them directly for their services.