Questions and Answers

  1. How do you maintain a green roof?

    “Extensive” (ground cover) green roof maintenance is minimal – just check the drains once a month.

    “Intensive” (garden-type) green roof maintenance depends on your gardening habits – check the drains once a month, plus any other sort of trimming, fertilizing, and replanting.

    For any roof, Eixverd (through Tarpuna Cooperative) can take care of everything for you starting at EUR 100 per month.

  2. Do green roofs leak and cause dampness?

    Green roofs, like any rooftop, must be installed with a layer of waterproofing, which should be tested for leaks. If the waterproofing is installed properly, leaks actually occur less frequently because the thermal insulation provided by the plants reduces the thermal stress on the waterproofing layer. Rooftops without the plants see higher thermal stress and need to be waterproofed more frequently.

  3. How do I install a green roof?

    Green roofs have a number of layers, each playing a key role in the overall system: 1) the waterproofing layer, 2) the anti-root layer, which protects against rotting, 3) the water retention layer, 4) the drainage layer, which provides a reservoir for rainwater and air to encourage root health, 5) the filter, so that particles do not clog the drainage layer, and, finally 6) the actual dirt substrate where the plants live.

    “Extensive” (ground cover) type roofs have a mineral substrate between 8 and 15 cm thick. The plants are sedum and grasses.

    “Semi-intensive” roofs have an organic substrate between 20 and 50 cm thick, with grasses and shrubs, even small trees.

    “Intensive” roofs have deep substrates able to support large trees.

  4. Does Eixverd guarantee its work?

    Yes. Eixverd stands behind its work, and guarantees its waterproofed green roofs for 10 years. 

  5. I have a communal terrace. What do I do to convince my neighbors about a green roof?

    Eixverd can recommend lawyers expert in community management who are available to mediate and help find appropriate solutions for your rooftop space.

  6. What's the difference between a roof and a terrace?

    We use the word “roof” as a general term to include private terraces, community terraces, with asphalt or tile, and on top of the building or in the building interior patio.

  7. How do I get a cool roof?

    After exploring your specific case, we can advise on various options available to you. In most cases, a mere coat of paint to the rooftop surface would be enough to get benefits.

  8. Does the government provide financial support?

    The City Council through its Housing Consortium provides up to 25% assistance on the rehabilitation of buildings. However, if the rehabilitation adds energy efficiency – such as a green roof, cool roof, or solar panels – then the government will pay up to 50% of the costs. To find out more, visit IDAE (Institute for Energy Diversification and Saving).

  9. How much do green roofs and cool roofs cost?

    An “extensive” (ground cover) type green roof, including automatic irrigation and waterproofing, costs around 100 EUR/m2. Without waterproofing the price falls to 60 EUR/m2. You can get a cool roof for as little as 20 EUR/m2.

  10. If you did not find an answer to your question, send us your question and we will publish the answer!