Designed in the 1960s by Pino Pizzigoni, the concrete tent-church, was subjected to a delicate restoration and conservation works of the reinforced concrete. The building consists of four identical and independent sections with joint that allows each of the four sectors to have statically independent behavior from the others. The structure of the church is composed by vertical and sub-horizontal pillars with a predominantly circular section, connected by double curve thin vaults. In aerial projection, each of five vaults is a twisted quadrilateral with a concave section stretched along one diagonals and a convex section subject to compression along the opposite diagonal. The peculiarity of tent-church’s vaults is the executive process; indeed, all the concrete structures were made by cast-in-place concrete using wooden formwork and reinforcing bars with diameter equal to 12 mm placed along the diagonals of twisted quadrilateral. The thickness of concrete shell ranging from 4 and 6 cm. The low thickness of the vault make it particularly vulnerable to aggressive environment. The restoration and conservation work just finished was not the only interested in the church of Longuelo. In January 1985, following an extraordinary and heavy snowfall, the roof of the church was severely damaged and a lighter copper roof replaced the roofing slate, due to the high probability of collapse. At the same time, localized concrete covers were made with traditional mortars of different color respect to original surfaces. However, the main repair work on the church was the application of a low-thickness waterproofing coating with protective features. Unfortunately, this coating influenced the concrete elements exposed directly or indirectly to rainfall, determining corrosion of reinforcement bars and spalling of concrete cover. The concrete element that constitutes the doorway of church has been subjected to intervention even in a third step using a waterproofing polymer-cement mortars.