EPDM Roofing Membrane on Spanish Urban Garden | Elevate EMEA

RubberGard EPDM waterproofing membrane from Elevate EMEA was used in the creation of a green roof. Casa d'en Xifré is an apartment block situated in Barcelona. The block consists of 6 buildings that were originally built in 1837. In 2019 the untouched facades underwent rehabilitation. Part of the new design included connecting the roofs of the different buildings to create an accessible terrace garden that aimed at enhancing urban biodiversity.

Design Concept

The Barcelona City Council promoted an open competition for the design of green roofs. The winners, MataAlta studio created a design concept on 'rewilding' which aimed at reintroducing nature in urban buildings, focusing on self-sufficiency, social interaction, and biodiversity. The design included insect hotels, water ponds, nesting structures, small ponds with fish, and composters.

Materiality and Structure

The materials for the project were carefully selected to achieve a low carbon footprint. To optimize the design and its environmental impact certain steps had to be taken. First, a detailed structural study of the bearable loads was carried out which took into account the green roof design. The top of the roof structure which held the greenery consisted of the following layers:

(From bottom to top)

• A bottom geotextile layer made from traditional Catalan ceramic tiles
• RubberGard EPDM waterproofing membrane from Elevate EMEA
• A second geotextile layer
• A drainage layer with an irrigation system

The roof carries about 20 to 40 cm of soil that contributes to the building's waterproofing, sound, and thermal insulation as well as being the basis for the vegetation to create the biodiverse ecosystem.

Vegetation

The vegetation mainly consists of native perennial plants that are pollinator-friendly, aromatic, drought and disease-resistant, and pollution-filtering. The green roof is able to hold up to 50% water. Any excess water is stored in an underground cistern which is pumped up to water the garden during the hottest months. The garden acts as a place of recreation and socialization for the building's inhabitants.

Project Details