Minimats for the Kitchen Roof

Sedum Master  - Sedum Minimats®

Throughout the design process (across the winter of 2013-2014) there was a constant battle over weight. What can the roof hold vs what would we like put onto it.  How heavy are the sedum panels when wet (at field capacity)?  How much growing medium?  

Very early on, I gave up on the idea of using sedum plugs and "planting" them into growing medium, and waiting a season or two for coverage. I elected for an instant roof with 100% coverage provided by mats / tiles.

In the end, we opted for Minimats on top of one inch (25mm) of growing medium, on top of two water storage layers, drainage layer, etc

One of the considerations about the kitchen roof was that I look at it every day, and I had my heart fixed on a "look" that was a mixture of red and green, even early in the summer - to complement the variety of greens available from the ravine backdrop.  

Having Googled every sedum mat vendor from Windsor to the Gaspe, I had converged on a particular light weight Sedum Master product that I could install by myself via a ladder. 

However, this product was taken from the market in 2014 for a variety of commercial licensing reasons.  They did replace it with a delightful "Minimat" product that I was assured would be green with plenty of red.  

The Minimats are 1' by 2' (0.3 by 0.6m) in size and weigh about a pound, dry.  You can carry three of them up a ladder single handedly. They weigh about 0.1 KPa, saturated, compared with 0.3 KPa and up for other sedum mat products.

The product is grown in a tube house, and you need to watch your hardening for early (April) purchases.  Late winter frosts can go a long way to hurting an early spring installation.  

The Minimats appear to be based on an open weave plastic matrix material, not unlike the "drainage layer" material, turned upside down so the geo-textile is on the bottom.  The "growing medium" appears to be a peat moss and perlite - very light weight even when wet. The assembly is about 5 cm (2") high / thick when you but it.  

The species mix is mostly broad-leaved and big fat succulent leaves. So far I have been able to identify several species of Sedum Spirium, and Allbum, plus Cherry Tart and Lime Zinger - about 8-10 different ones.

I rented a van and drove to Princeton to pick up my 54 pieces - not an unpleasant trip from Toronto.  

The price was about $6 per square foot in 2014, in small roof quantities of about 100 sq ft. (10 sq m)

Here are all my mats stacked on the deck ready for installation.  
They can stack 5-6 high without obvious damage.

    

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Sedum Master, can be found 746645 Township Rd. #4, Princeton, ON N0J 1V0,  Phone: 1-888-458-4061, Fax: 519-458-8883.  
www.sedummaster.com
Princeton is a rural community south west of Cambridge, ON.