| Key Takeaways | |
|---|---|
| Definition | Sedum roofs are lightweight “living roofs” planted with hardy plants that thrive in shallow soil. |
| Irish Climate Suitability | Ideal; consistent rainfall and mild weather keep sedum roofs healthy year-round with little maintenance. |
| Main Benefits | Improves roof insulation, reduces stormwater runoff, and looks visually appealing. |
| Main Drawbacks | Adds weight and cost, can complicate waterproofing, and offers limited real carbon savings. |
| Cost Range (Installed) | Approx €45 + VAT / m² for light sedum mats; Approx €65 + VAT / m² for heavier mats. |
| Best Use Cases | New builds, extensions, modular homes, and urban projects needing rainwater control. |
| Verdict | Great for beauty, comfort, and minor eco-benefits; but not a major climate solution in any way. |
What Is a Sedum or Green Roof?
- A green roof is a building roof that has been covered with a layer of living vegetation.
- A sedum roof (the most common type in Ireland) uses hardy, low-growing succulents from the Sedum family. These plants thrive in shallow soil, survive droughts, and stay green most of the year; perfect for the Irish climate.
A typical green roof system includes:
- Waterproof membrane to protect the roof structure.
- Root barrier to stop plant roots damaging the roof.
- Drainage and filter layers to manage rainfall.
- Lightweight growing medium (about 5–15 cm deep).
- Sedum or wildflower plants forming the visible green layer.
| Type | Description | Typical Weight | Maintenance | Cost (€/m² ) |
|---|---|---|---|---|
| Light Sedum | Thin, lightweight, mostly self-sustaining | 35 kg/m² 20mm depth | Low | Approx €45 + VAT / m² |
| Intensive Sedum | Deeper soil | 70 kg/m² 50mm depth | Mild | Approx €65 + VAT / m² |
Why Sedum Roofs Work in Ireland.
Ireland’s climate makes sedum roofs naturally successful; regular rainfall, mild temperatures, and long growing seasons keep them looking healthy without constant watering.
The Practical Benefits
- Reduces Rainwater runoff – absorbs heavy downpours and slows drainage, easing pressure on city storm systems.
- Extends Roof life – as it shields membranes from UV rays and temperature swings.
- Improves Sound insulation – dampens rain and outside noise.
- Looks beautiful – adds colour and life to otherwise dull rooftops.
Challenges & Disadvantages.
Many homeowners install sedum roofs believing that they are drastically reducing their carbon footprint. This is where the idea of ‘greenwashing‘ in my opinion comes in.
1. The Embodied Carbon Issue
Most emissions from a home come during construction; through cement, steel, insulation, transport, and waste. Adding a green roof later adds more manufactured layers (root barriers, drainage mats, plastics, growing medium).
If structural reinforcements are needed to handle the extra kgs/m², the embedded carbon rises further.
The result?
It can take 20 – 40 years before the carbon savings of a sedum roof offset its added materials, and that’s only assuming it’s well-maintained.
2. Maintenance and Leak Risks
Flat or low-slope roofs in Ireland face heavy rainfall. Water collects, soil gets saturated, and leaks can form unseen below the layers. Finding a leak under a green roof could possibly mean removing large sections – not cheap!
Even with modern waterproof membranes, drainage design is critical.
3. Added Structural Load
A saturated sedum roof is heavy. Older buildings may need reinforcement before installation. That means more concrete or steel, which again eats into sustainability claims as already mentioned above.
Let’s Look at the Issue of “Pretty Sustainability”.
Our urban cities are concrete jungles with limited green spaces. And I can understand why some city dwellers may desire green roofs; the way they look and how they make them feel (calmer, closer to nature, and proud of “doing their bit”).
I find it quite sad and a little ironic even, that we pave over grassland, fill it with concrete and then add a small patch of grass on our roofs just to feel sustainable. But then again, mortgage systems force us to buy into pre-built homes that we spend lifetimes trying to shape into our own image. Minor rant.
Anyway, the irony I mentioned above is indeed real. And for many home-owners, a sedum roof is more about symbolic greening than ”trying to save the planet”.
I do not mind it personally – as long as it’s honest.
Efficiency alone does not make a good/fun life. We as humans crave beauty, pride, texture and connection. Now, a green roof will not reduce carbon emissions as intended, but it is beautiful and can make people become gentler with their surrondings. And that social effect, to me, has value in itself.
So yes, a green roof may be more about how we want to live than how we need to build. And that’s perfectly fine… as long as we’re honest about it.
When Sedum Roofs Do Make Sense in Ireland.
| Scenario | Why It Works |
|---|---|
| Urban Developments with Sealed Surfaces | Helps absorb rain and reduce flooding risk. |
| New-Build Projects already under construction | Easier to design structure and waterproofing properly from the start. |
| Garden Rooms, Extensions | Adds insulation and beauty with manageable weight. |
| Commercial or Public Buildings | Large roof areas make water management benefits measurable. |
In these cases, a sedum roof can genuinely improve sustainability and roof longevity; as long as expectations remain realistic.
Reputable Green Roof Installers in Ireland
| Company | Location | Services | Website |
|---|---|---|---|
| Green Roofs Direct Ltd Formerly Green Roofs Ireland | Magheramorne, NI | Sedum blankets, pebble borders, wildflower mats, maintenance | greenroofsdirect.com |
| LandTech Soils | Nenagh, Co Tipperary | Sedum, wildflower, grass, maintenance | landtechsoilss.ie |
| IKO | Dublin, Cork, Antrim | Sedum, green walls | iko.ie |
| Grasshopper | Dublin | Sedum blankets, green roof maintenance | grasshopperservices.ie |
| Quinn Roofing | Wexford | Large-scale commercial green roof systems | quinnroofing.ie |
Always confirm load-bearing capacity and waterproofing warranties before installation.
Honest Verdict
| Factor | Verdict |
|---|---|
| Aesthetics | Excellent; visually softens the look of modern homes which are too angular. |
| Climate Fit | Ideal, regular rainfall keeps sedum lush. |
| Environmental Impact | Realistically negative – offsets take decades. |
| Maintenance | Moderate, drainage & waterproofing must be managed. |
| Practical value | Good for rainwater control and roof protection. |
| Best use case | New builds, extensions, and garden offices. |
Green roofs are not a magical shortcut to sustainability.
However, my initially harsh view on them softened as I carried out more research. They’re a reminder that beauty and conscience sometimes meet halfway; in the small, green spaces we create amidst the all the concrete.
