Projects / 4/14/2025

The temperature drops, the rain becomes more intense and frequent, but the installation of porphyry never stops

The urban redevelopment of the Valleve town center involved the use of Mapestone Joint Ghost to grout the joints and create flexible and pervious architectural stone paving

Author

Grazia Signori

Architectural Stone Paving Line Specialist, Mapei

Autumn arrives early up in the mountains, bringing with it the cold and rain that can complicate and slow down site work, especially the installation of stone paving. This could have been a concrete risk for the redevelopment of the old town centre of Valleve in Northern Italy. Instead, thanks to the experience and constant hard work of the Works Director and installation team, who opted to use a specifically formulated innovative product (Mapestone Joint Ghost), installation continued without a break, despite the persistent cold and damp conditions. And in so doing, installation of flexible, pervious and resistant stone paving was completed on schedule.

A tiny mountain hamlet with a noble past which today, however, has just 131 inhabitants, sitting at the top of Val Brembana: this is Valleve, a municipality 50 km from Bergamo (Northern Italy) where, thanks to funds from the Lombardy Regional Government as part of a more extensive tender for “Works to initiate the process of urban redevelopment”, it was possible to carry out this urban redevelopment work in the old part of the hamlet.

The old town centre of Valleve (Province of Bergamo) was lately redeveloped.

The works enabled the paving, underground service networks and polyfunctional rooms in the museum to be completely refurbished.

The project is an urban redevelopment initiative aimed at transforming and improving accessibility and mobility in and around the area and to enhance the local historic and cultural heritage that characterises the old part of the hamlet, which today has only around 10 residents.

The works included a series of specifically designed technical operations to optimise the public spaces in the hamlet, which are destined to play a pivotal role in the daily life of the inhabitants, tourists and visitors attracted to the area by the landscape and panoramic footpaths that wind their way up the Orobie mountains, and the Museum of Local Traditions, which is also being refurbished as part of the project.

During the tourist season, in fact, the population increases threefold, and the aim of the Local Authorities was to revitalise the hamlet to provide the residents with more welcoming, more inclusive and more sustainable public spaces with the intention of maintaining the population which, because of the constant lack of work, leave the area in search of better services.

The new porphyry paving in front of the Museum of Local Traditions was completed with Mapei solutions for stone paving.

The stone paving in the hamlet is one of the key elements in improving the aesthetics and functionality of the public spaces.

The materials and construction techniques specified by the project were chosen according to two guiding principles: the use of materials and construction techniques similar to the existing ones and the introduction of new elements that guarantee excellent results, while remaining in line with traditional local construction practices and examples of construction practices already adopted in the area.

The main parameters considered when choosing the materials were:

the cost/aesthetics relationship;
future maintenance requirements;
availability on the market of materials and labour specialised in this type of installation work.

The project included the complete refurbishment of the previous stone paving which, over the years, had become deformed and out of flat due to the freeze/thaw cycles, so unsafe for pedestrians, by installing flexible, pervious paving made up of 80/100 mm porphyry blocks installed in an arched pattern over a bed of 4/8 mm crushed stone on a cementitious screed reinforced with electro-welded steel mesh, with joints infilled with 3/6 mm crushed stone and grouted by pouring a binder like MAPESTONE JOINT GHOST in the joints which is especially suitable for use in the case of adverse weather conditions.

MAPESTONE JOINT GHOST is an innovative one-component, solvent-free, silane-terminated polymer binder with rapid curing and drying properties which is not sensitive to moisture, specifically formulated for sealing joints for setts, blocks and pebbles used to create flexible, pervious architectural paving that needs to be put into service quickly. Indeed, the drying time and curing time of the product is around 4 hours.

Thanks to its special composition that does not contain isocyanates, the product respects the environment and safeguards the health and safety of installers who do not require specific training for using it.

MAPESTONE JOINT GHOST may also be applied if the infill material and stone elements are not completely dry.

Another advantage of MAPESTONE JOINT GHOST is its transparency, thanks to which the colour of the joints is determined solely by the colour of the infill material.

This product complies with the classes of traffic loads according to EN 1341 and with the safety requirements, such as non-flammability, and safety of use during application, storage and transport.

Application of MAPESTONE JOINT GHOST to seal joints for setts, blocks and pebbles, creating flexible, pervious architectural paving.

Stone paving correctly installed with MAPESTONE JOINT GHOST means that only limited maintenance will be required over the years because it is particularly resistant to freeze-thaw cycles, de-icing salts, bad weather in general and the chemical action of contaminants such as fuel and oil.

Also, thanks to its flexible behaviour, expansion joints do not need to be included, and paving is able to absorb the heavy loads and mechanical stresses caused by the passage of heavy vehicle without hazardous potholes forming due to settling and subsidence in the installation bed.

MAPESTONE JOINT and MAPESTONE JOINT GHOST in their packages.

Another advantage of using MAPESTONE JOINT GHOST is the speed at which paving can be put back into service, which can be reopened to traffic just 48 hours after installation at 20°C.

This type of installation ensures that paving remains sound and long-lasting with the capacity to withstand the daily stresses it must be subjected to, including more severe load classes, and, above all, bad weather conditions such as heavy rain, freeze/thaw cycles or when the use of de-icing salts is required.

Two installers apply MAPESTONE JOINT GHOST on the joints with a third operator gradually drying the paving.

Weather conditions are a decisive factor in completing the installation of flexible, pervious architectural stone paving and can often interfere with site schedules, especially when the temperature drops, and the drying time of the paving is extended.

Thanks to its special formulation based on silane-terminated polymers, MAPESTONE JOINT GHOST makes it possible to grout joints during rainy days, after rainfall or if rainfall is expected within a few hours after the works.

Thanks to the use of MAPESTONE JOINT GHOST for the final stages of the works, the installation of the paving in Valleve town center was completed despite the adverse weather conditions, in full compliance with the deadlines.