A geomembrane with a low initial cost might cost you just as much, if not more than, a geomembrane that costs more upfront. Before signing the check, you should uncover the real geomembrane cost by looking at usual costs incurred over the lifespan of the product.
To illustrate the point, this article discusses the differences between high-density polyethylene (HDPE) and ethylene interpolymer alloy (EIA) geomembranes (like XR-5® Geomembranes). Regardless of the products you’re comparing, the geomembrane cost breakdown categories will be relatively similar.
Initial costs can be broken down into three main areas: material costs, installation fees, and the cost of construction quality assurance (CQA). Although material costs have a serious impact on the lifetime cost of your geomembrane, for less expensive materials, a good portion, if not the majority, of capital will be spent on labor. Below is a chart depicting some key differences.
The final segment of the price breakdown shows the cost impact of adding a geotextile to a geomembrane. EIA geomembranes inherently have superior puncture strength, as they can withstand over 800 pounds of ball tip puncture resistance, so they can often be used without a geotextile as depicted by the chart below. Other geomembranes on the market do not have that luxury, however, and need supplemental materials to increase puncture strength to the same level, resulting in additional geomembrane costs to the overall installation price.
Your geomembrane must be maintained regularly in order for it to continue performing at its best. The amount of maintenance necessary varies however from one geomembrane to another. Some geomembranes, like HDPE, are plagued by environmental stress cracking (ESC), while others, like EIA, are engineered with low thermal expansion properties making these geomembranes more dimensionally stable. ESC can occur anytime during the lifespan of your geomembrane, meaning you might have to replace the geomembrane entirely before seeing a return on your investment.
Ultimately, you should not decide on a geomembrane solely based on the initial cost. Extra expense will sneak up on you, resulting in a greater lifetime cost. Make sure to do your research and weigh your options to find a product that fits both your performance and budgetary requirements.
What other costs do you consider when determining the lifetime cost of a geomembrane? Share your thoughts in the comments.