While We Wait, Prepping The Main Roof...

The Main Roof

While we wait for the sedums for the kitchen roof to be "hardened off" at the nursery and picked up, its time to get started on the main roof.

The main roof is also a "flat roof" : an area of about 600 sq ft clear (approx 60 m2).  It was designed from the outset to hold a green living roof and / or solar panels, up to a certain (weight) point.  

Through the design process, repetitious calculations and Municipal "discussions" we worked toward a design that has 4" (100mm) of growing medium on the main roof, and 6" (150mm) of growing medium on the upper roof (of the 3rd storey walkout).  Both these areas would be topped with the XEROFlor XF301 XF301 pre-vegetated Sedum mat. More about it later.

Our PV solar panel array consists of 21 panels taking up about half the main roof.  Efficiently distributed for a PV array, but leaving difficult spaces for a living green roof. 

As with the kitchen roof, the first layer to be added is the "protection" layer. Strongly recommended by the roof membrane manufacturer if we wish to keep our 15 year warranty intact. 

Strongly recommended by me even if you don't plan to drop scissors, drills and other sharp objects..... I'm not usually a "belts, braces and both hands" person, but when it come to roofs and other things that are excessively difficult to fix, I'm quite happy to slather on thick protection.

As before, we used the DUROLAST WalkTRAK III product, and cut it to fit our geometry.  The yellow overlap edges are irrelevant for us - its just some pieces of WalkTRAK we found (recovered) from the builders storage, leftover from another roofing job.

The large open area north of the "walk-out".

The fitting of the material was not a big deal, although it does take some time and a bit of cutting.  All my fiddling took a day to do both of the upper roofs.  I elected to do  all my cutting on the wooden deck. It was a bit safer. all things considered.

The WalkTRAK III material comes in 5' by 5'  (1.5m by 1.5m) and 5' by 2.5' (1.5m by 0.75m) sizes.  You just need to conserve your big pieces for the large open areas and be prepared to use the off-curs and scraps everywhere else. We probably have a bit more overlap in some places than is strictly needed, especially in the high traffic zones where we would be walking long term on" Walking Panels".  More about Walking Panels in tomorrows blog.

And after all of that we still have some scrap left over for a variety of "projects" in the coming decades.

If your roof manufacturers warranty is not an issue, then you should consider other possibly cheaper protection layer material.  For a while I looked at the thickish mats that machine operators stand on in a machine shop. So long as it is continuous, and sufficiently thick to stop sharp chisels, nails, scissors and spinning drill bits from penetration, then you are likely good to go. The "Uline" catalogue (www.uline.ca) has a good selection of contenders.