Kitchen Roof Topping Off
After about a year of eager anticipation, the big day had arrived when I could finally, put the living / green layer onto the kitchen roof.
Rain, a couple of days prior, had wetted down the water storage layers so I did not feel the need to wet them especially.
The first layer to go on today is the "growing medium". It will provide basis for rooting by the sedums, eventually, plus a modest amount of water storage. In reality, it will keep the sun a further inch away from our kitchen, to reduce our summer cooling loads.
"Growing Medium" a mineral based manufactured material, never to be confused with soil / triple mix and the usual bunch of horticultural soils. The difference is that growing medium is predominantly mineral or aggregate based with only a small portion of organics. It does not break down as easily as soil, which has a much higher organic proportion. If you were to use "soil" on your roof, then it would eventually breakdown, lose its structure and flow away like mud. Ans soil can get very heavy when its is wet : it can have a very high "field capacity".
The downside of using growing medium is that it does not easily provide nutrients to the plants. so we will need to add these regularly, in perpetuity.
In our installation we used XeroTERR growing medium from the XERO Flor company.
"XeroTerr" is described officially as a "Lightweight aggregate growing medium mixed specifically for use within Xero Flor mats and green roof system build-ups. (It is) A proprietary mixture of lightweight, mineral based materials; including porous aggregate and organic matter derived from composted plant materials." Our batch had a noticeable portion of crushed brick in it.
From the labels on the 1 yard totes, this material was manufactured locally in Ontario.
The growing medium is spread in a layer: raked but not compacted. On this roof the layer was about an inch thick (25mm). That is as much as we could put onto the roof and stay within the structural strength limitations.
I will add that the hardest part of the work was the lugging of the growing material around from the driveway (where it had been delivered in 1 yard sized totes) and up the ladder.
Rain, a couple of days prior, had wetted down the water storage layers so I did not feel the need to wet them especially.
The first layer to go on today is the "growing medium". It will provide basis for rooting by the sedums, eventually, plus a modest amount of water storage. In reality, it will keep the sun a further inch away from our kitchen, to reduce our summer cooling loads.
"Growing Medium" a mineral based manufactured material, never to be confused with soil / triple mix and the usual bunch of horticultural soils. The difference is that growing medium is predominantly mineral or aggregate based with only a small portion of organics. It does not break down as easily as soil, which has a much higher organic proportion. If you were to use "soil" on your roof, then it would eventually breakdown, lose its structure and flow away like mud. Ans soil can get very heavy when its is wet : it can have a very high "field capacity".
The downside of using growing medium is that it does not easily provide nutrients to the plants. so we will need to add these regularly, in perpetuity.
In our installation we used XeroTERR growing medium from the XERO Flor company.
"XeroTerr" is described officially as a "Lightweight aggregate growing medium mixed specifically for use within Xero Flor mats and green roof system build-ups. (It is) A proprietary mixture of lightweight, mineral based materials; including porous aggregate and organic matter derived from composted plant materials." Our batch had a noticeable portion of crushed brick in it.
From the labels on the 1 yard totes, this material was manufactured locally in Ontario.
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| A bucket of growing medium |
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| Two Minimats ready to be placed |
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I ended using a kneeling board just to prevent compaction of the growing medium. You basically lay down the Minimats and jam them against each other. |
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Shaping of mats to fit "geometry" is really easy, requiring only a sharp cutter, a board, and some elbow grease. |
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| End of the first row, fitted to the outlet shape. |
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| Repeat until finished. |
I will add that the hardest part of the work was the lugging of the growing material around from the driveway (where it had been delivered in 1 yard sized totes) and up the ladder.
There was very little wastage or "left over" sedum minmat. One spare piece would usually be sufficient if your area calculations are good. We had both our "spare" and two half mats declared surplus to requirements. They will be used somewhere else round the garden.
I did water it quite well on the first day - until the water ran from the gutter. Overnight the sedums "perked up" noticeably an soon poked a good inch above the railing. A couple of warm days also helped their recovery.
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This is the view from my office at the end of installation. The sedums are a bit squished, but will (did) recover very well after a good watering and a couple of warm days. |
Later Comment : We are noticing a gradual change in the look over time. The sunny parts of the roof are becoming quite a bit redder and the taller species are beginning to poke through. I'll post some progress pictures later on.
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Xeroflor Canada Inc. is located at One Yonge St., Ste 1801, Toronto, ON, Canada, M5E 1W7
Tel: 416.637.5772
General Mailbox : info@xeroflorcanada.ca
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