The Under Restaurant
Snøhetta has designed Europe’s first restaurant below sea level. “Under” combines design and technology to astound diners, who are all amazed by this incredible sight and the technological challenge the project embodies.
Style, comfort and safety were the guidelines followed by the Norwegian firm, which turned to Mapei for repairing and smoothing the concrete, carrying out the structural bonding and waterproofing operations, and installing the tiles.
A monolithic structure made from reinforced concrete
The Under Restaurant is a monolithic structure made from reinforced concrete. It is 34 m long and slopes away into the sea down to a depth of 5 m, where it rests on the seabed just off Lindesnes, the most southerly point of the Norwegian coast, around a one and a half hour drive from the nearest airport and five hours from Oslo.
The interior spaces of the restaurant are protected by a 1 m-thick reinforced concrete shell designed to withstand the pressure of the water and the particularly harsh climatic conditions both above and below sea level. The designers decided to leave the exterior surfaces of the construction with a rough, exposed concrete finish to encourage the growth of seaweed and mussels below the waterline and to make the structure seem part of the rocky coastline where it is situated. Thanks to its particular location, the building is also intended to become an observation point to control the surrounding marine environment.
Working below sea level
The structure is made from precast modules and is anchored to a block of concrete. A walkway links the rocky coastline to the entrance of the restaurant, which opens onto an interior space with a surface area of 600 m2 over three levels descending into the sea. On the top floor, or “zero” floor, there is the reception and cloakroom, followed by a bar at the mezzanine level and then a lower floor where the restaurant, with seating for up to 100 guests, is situated. The dining room has a panoramic window with a double layer of acrylic glass looking out directly onto the seabed.
Because of its special design and complexity, the project required a large range of high quality and technologically advanced products.
The products supplied included CONFIX*, CONFIX FIN* and REDIREP 45 RSF* to repair the concrete, epoxy resin-based products and hi-flow mortars for anchoring elements in place (such as MAPEPOXY BI*, MAPEPOXY LR*, MAPEPOXY L* and NONSETT 400*), MAPEFIX VE SF for chemical anchors, MAPEPRIMER M* epoxy primer for treating concrete substrates with surface moisture, PLANITOP FINE FINISH ultra-fine-textured skimming compound for exposed concrete, RESFOAM 1KM and RESFOAM 1KM AKS* resin for waterproofing structures subject to intense water seepage and SUPERFLYT* super-plasticising admixture for mortars. ULTRABOND MS RAPID adhesive was chosen for its high sucker effect and rapid setting properties to install the 3D ceramic tiles in the bathrooms.
*These products are manufactured and distributed on the Norwegian market by Mapei AS (Norway)
The structure is made from precast modules and is anchored to a block of concrete. Because of its special design and complexity, the project required a large range of high quality and technologically advanced products.