Unexpected peat deposit
Year Completed: 2018
Ed Stec with JV Vang Construction was working on Nompeng Academy’s expansion and a new
parking lot that was earmarked for the open field next to the stormwater pond.
When the construction crew ran into an unexpected peat deposit located where the parking lot was to be built, Curt Johnson with Northern Technologies, LLC recommended that rather than incurring the cost of excavating and replacing the deep peat layer with off-site conventional soil, they would instead float the parking lot over with lightweight fill.
The two lightweight materials evaluated were a two-foot layer of TDA (tire-derived aggregate) or
polystyrene (geofoam). When looking at the cost and ease of placement, TDA was faster to install and was less than 1/10 the cost of the alternative lightweight fill solution.
TDA’s lightweight property helps prevent the parking lot from sinking into the peat and will also
provide a capillary break to eliminate the risk of frost heave and related moisture problems.