When I climbed onto my roof the first time I knew I had to have a little spot to hang out up there. I have an interesting view of the working part of the harbour and a bit of table bay and onward to some mountains that I have yet to identify. I also have a full postcard (almost) view of table mountain. Lucky for me, the previous homeowner seemed to have the same idea and raised the parapet wall to about 1.1 meters above the roof. This gives me privacy from the street, wind protection, and a sense of safety.
My next door neighbour has a rooftop deck and she has had a slight leak that has given her trouble for years that she can't fix properly without dismantling her deck. This was a big concern for me, so i decided to replace my roof with a structure that can bear plenty of weight, add a reliable waterproof membrane, and lay a light, modular deck directly on the roof surface. I designed and built it to be easily dismantled in sections. Should the roof or membrane require maintenance or repair, a quarter of the deck can be dismantled and rebuilt in an afternoon.
Here is a quick sketch that I used to communicate my vision to my fiancee:
The roof work had to be done quickly and reliably because our brand new kitchen is under it, so I hired a roofer. Once it was closed up I would have my fun building the deck on my own.
After removing the IBR roof sheets, I had 228 x 38 joists installed at 500 centres. One end of each joist is wrapped in DPC and built into the wall and the other end rests on the wall plate. Noggins brace the joists and prevent twist. Plywood sheets are then screwed to the substructure in a staggered pattern with joints directly over the joists and noggins.
Two layers of bitumen membrane were then applied. The first was nailed down with small wire nails with broad heads. The torch on bitumen membrane won't adhere well to the plywood surface, so this membrane is fixed in place and then the torch on layer fuses to it, giving me a 6mm waterproof barrier. The parapet walls are then waterproofed with a cloth membrane and acrylic brush-on product which overlaps the torched membrane providing a very thoroughly protected roof. The membrane hangs over the edge directly into the gutter (gutter not shown in photo). A product called Silvacote reflects the suns damaging rays and preserves the bitumen.
So at this stage I've got a super strong well protected roof, ready to support my deck!
I chose treated pine because it is cheap, sustainable, and we use it almost exclusively in Canada, so I know it can handle the weather. It is very important however, to specify H3 treatment which is not what you find "off the shelf" at your local timber & hardware shop. The hardware shops stock H2 timber which is used in roofs and covered structures that may be exposed to minimal moisture. H3 treatment can tolerate full outdoor exposure above ground. H4 treatment ratings can handle submersion in water and burying in the ground, but that is not necessary here.
The joists or 'feet', for lack of an appropriate term, are cut in wedges to correct the fall. The bottom edges are rounded so as not to cut or dig into the bitumen membrane, and an additional 4mm thick strip of bitumen is laid beneath each. I can inspect these strips annually or bi-annually and replace them if they show wear and never compromise the waterproof membrane.
I wanted any person who might conduct maintenance to see clearly that removal could be done in sections, so I chose not to stagger long decking planks but rather align the joints of each section of deck.
I included planter boxes which would hold bushes grown in buckets not only for aesthetics and atmosphere, but to provide a sturdy base for handrails in the absence of a sturdy substructure. The bushes and planter boxes were also intended to prevent anyone from putting their full body weight against the railing. In any case it turned out to be more than strong enough.
If I have one regret it is that i stopped the planter box short of the stairway. I wanted the stairs and landing to be small so as not to block sunlight into the windows, and for some reason I didn't want to crowd the small opening. One day I may alter it and bring the planter over to the stairs.
I am very pleased with the design and construction of the staircase and landing. It is unique and adventurous and it is the result of several restrictions. I wanted to look out of my windows and see my open uncrowded small courtyard. I didn't want awkward posts to break up my space. I didn't want to block much sun. The run of the staircase was restricted because of the entrance to a planned outdoor kitchen. I needed something steeper with a shorter run.
I decided to hang beams between the two walls of the courtyard eliminating the need for posts to support the stairs. I designed an alternating tread 'space saving' staircase up to the landing, then a traditional flight up to the top.
The tread height is a comfortable and manageable 195 mm.
Overall I am very pleased with the finished project.
My next door neighbour has a rooftop deck and she has had a slight leak that has given her trouble for years that she can't fix properly without dismantling her deck. This was a big concern for me, so i decided to replace my roof with a structure that can bear plenty of weight, add a reliable waterproof membrane, and lay a light, modular deck directly on the roof surface. I designed and built it to be easily dismantled in sections. Should the roof or membrane require maintenance or repair, a quarter of the deck can be dismantled and rebuilt in an afternoon.
Here is a quick sketch that I used to communicate my vision to my fiancee:
The roof work had to be done quickly and reliably because our brand new kitchen is under it, so I hired a roofer. Once it was closed up I would have my fun building the deck on my own.
After removing the IBR roof sheets, I had 228 x 38 joists installed at 500 centres. One end of each joist is wrapped in DPC and built into the wall and the other end rests on the wall plate. Noggins brace the joists and prevent twist. Plywood sheets are then screwed to the substructure in a staggered pattern with joints directly over the joists and noggins.
Two layers of bitumen membrane were then applied. The first was nailed down with small wire nails with broad heads. The torch on bitumen membrane won't adhere well to the plywood surface, so this membrane is fixed in place and then the torch on layer fuses to it, giving me a 6mm waterproof barrier. The parapet walls are then waterproofed with a cloth membrane and acrylic brush-on product which overlaps the torched membrane providing a very thoroughly protected roof. The membrane hangs over the edge directly into the gutter (gutter not shown in photo). A product called Silvacote reflects the suns damaging rays and preserves the bitumen.
So at this stage I've got a super strong well protected roof, ready to support my deck!
I chose treated pine because it is cheap, sustainable, and we use it almost exclusively in Canada, so I know it can handle the weather. It is very important however, to specify H3 treatment which is not what you find "off the shelf" at your local timber & hardware shop. The hardware shops stock H2 timber which is used in roofs and covered structures that may be exposed to minimal moisture. H3 treatment can tolerate full outdoor exposure above ground. H4 treatment ratings can handle submersion in water and burying in the ground, but that is not necessary here.
The joists or 'feet', for lack of an appropriate term, are cut in wedges to correct the fall. The bottom edges are rounded so as not to cut or dig into the bitumen membrane, and an additional 4mm thick strip of bitumen is laid beneath each. I can inspect these strips annually or bi-annually and replace them if they show wear and never compromise the waterproof membrane.
I wanted any person who might conduct maintenance to see clearly that removal could be done in sections, so I chose not to stagger long decking planks but rather align the joints of each section of deck.
I included planter boxes which would hold bushes grown in buckets not only for aesthetics and atmosphere, but to provide a sturdy base for handrails in the absence of a sturdy substructure. The bushes and planter boxes were also intended to prevent anyone from putting their full body weight against the railing. In any case it turned out to be more than strong enough.
If I have one regret it is that i stopped the planter box short of the stairway. I wanted the stairs and landing to be small so as not to block sunlight into the windows, and for some reason I didn't want to crowd the small opening. One day I may alter it and bring the planter over to the stairs.
I am very pleased with the design and construction of the staircase and landing. It is unique and adventurous and it is the result of several restrictions. I wanted to look out of my windows and see my open uncrowded small courtyard. I didn't want awkward posts to break up my space. I didn't want to block much sun. The run of the staircase was restricted because of the entrance to a planned outdoor kitchen. I needed something steeper with a shorter run.
I decided to hang beams between the two walls of the courtyard eliminating the need for posts to support the stairs. I designed an alternating tread 'space saving' staircase up to the landing, then a traditional flight up to the top.
The tread height is a comfortable and manageable 195 mm.
Overall I am very pleased with the finished project.
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