Insulate your roof -
For insulation we have opted for 'Kingspan Styrozene 8350' a closed cell insulation that will not degrade in the wet weather of the West of Ireland. The insulation is applied externally to provide insulation outside the butyl membrane - keeping the dewpoint out at well.
To prevent the plat medium from slipping off the roof we then install three lateral 2 inch by 4 inch boards from eave to eave. The bottom board is about six inched from the gutter. The top boards get three 50 mil spaces, the second gets four staggered spaces and the bottom boards gets six staggered spaces of 100 mil each.
We then lay the membrane and slot the Kingspan insuation overit fitting snuggle between the places where the rubber is pushed up by the lathes.
We must now assemble an internal gutter
We plan to have an internal gutter that protrudes slightly over the walls. A hole is cut in the rubber to take a sleeve for a drainpipe.
First we bolt sections of 4 inch by 2 inch board onto the wallplate to act as counterlevberage for the gutter. Another 4 by 2 inch board creates a frame for a plywood gutter. This is eventually covered with a facia and sofit or set off with metal trim.
We are now ready to lay the specially manufactured rubber or butyl membrane on our roof. It lies loosely over the entire roof with one side counter balancing the other. It is glued to the edgging barge boards and gutter boards. A hole is cut in the bottom for a special gutter sleeve.
Next we apply a geotextile matting. This is the standard garden matting used to suppess weeds. In our case it provdes a barrier between the roots of bthe plants and the butyl membrane. It also gives the roots something to hold onto. Above that we need a water retardation layer mbecause we are buiding our roof on a slope. We intend to use foam tyles known as Biodrain, loosely aid on the roof 1metre x 750 cm in size. Finally a rectangular grid made of pastic holds the soil in pace.
Now we are ready to lay the soil
Spreading the soil on our green roof
The soil is spread evenly to a suitable depth for plants.
Rolling out the sod
In our case we will seed the roof with hrift, or Sea Pink a hardy perennial that is common on the cliuffs off the West of Europe
We are propagating it in nearby fields on mats.
A completed green roof structure in Scandinavia