Saturated Soils, What to do.
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A common problem Hardscaping™ contractors face each spring is wet soils. If you work in the Mid Atlantic region you probably know what it is like to walk on a jobsite and sink two inches into saturated clay soil. So, the question is what can you, the contractor, do to successfully build a stable Hardscaping™ installation when confronted by these conditions. There are degrees of soil saturation. When an excavation fills with water that is draining into it as a result of a subsurface flow, there is no practical solution other than to wait until conditions are dryer. If the soils are "pumping", meaning that water accumulates around the sole of your boot when you stand on that spot, it may be possible to overcome that condition by increasing the depth of your excavation by 50-100% of the depth normally required and get more stable soils. If you succeed, it is important that you achieve excellent compaction and use geotextile to line the excavation before installing the dense graded aggregate stone used for the base. If you do not achieve stable soil after doubling the depth of your excavation, you may put down a layer of ballast. This layer should be clean stone ranging from a minimum of 1 ½" to a maximum of 3" and should be compacted into the soft sub-base soil to tighten it up before installing any dense graded aggregate stone for the first layer of the base. For the best results, spread a layer of dry Portland cement on the soft soils of the excavation prior to installing the ballast layer. Then apply the ballast and compact it. It will be a dusty job but improve the sub-base stability. So, have a dust mask on hand for this approach. You may also want to clean the air filter of your compactor after doing that. The extra time spent in servicing your equipment can greatly extend the life of the engine that powers the unit. After the Portland cement and ballast installation, proceed in the same fashion as described previously. Line the sides and bottom of the excavation with a good quality geotextile. And for you rookies that is not "weed matt". Geotextile is a much stronger and durable material that has to meet specific strength standards and testing. This same material is now used as an underlayment membrane in most major construction projects I have seen over the past 10 years. Don't be fooled into buying something that will be inadequate for the demands of the job. It is essential that the base stone not be allowed to migrate into the soft soils and thus weaken the base construction. Geotextile can prevent a job from failing years down the road or later that same year as the soils dry and settle. Excellent compaction is always essential, and in applications like these it is even more important to make sure that you have achieved that 98% density standard. Most contractors do no have a Proctor density tester in their truck and certainly not a nuclear density measuring device. So the best bet is to put down thinner layers of base stone and compact them as much as you can to make sure you have the base as tight as you possibly can. A little extra time here can save a customer call back and a real loss of income or a tarnished reputation in that neighborhood. And for most contractors, word of mouth recommendations and advertising are the best source of new customers. _______________________________________________________________________ Ideally, you have a backlog of projects in which case the best solution is to rearrange your schedule to work at a site where conditions are better suited to the requirements of the project. If this is an option, be sensitive to the fact that the customer being delayed has been anxious to see their Hardscaping project completed but let them know you have their best interests in mind. They will get the best possible outcome if they can be patient with weather conditions. If they need affirmation, ask your customer to call EP Henry's Technical Information line at 800-44-HENRY to get answers to their questions about construction in saturated soil conditions. It also helps to call us before your customer does and let us know to expect that customer's call. Having a contract that allows for a surcharge in exceptional circumstances will also play into your favor. An impatient customer that does not see the wisdom of waiting a few more weeks may see things differently if they are faced with the additional costs of construction in extremely wet soil conditions. This is not pulling a fast one on the customer, simply managing a bad situation to the best possible out come for all parties involved. If you don't pile on more profits but simply pass along the additional costs you are being fair in trying to do the right kind of construction under poor conditions.
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