Fixing down the roof.

The rubber liner had been stretched over the roof for over 2 weeks. We rolled it up around a length of timber and wiped it clean with a cloth.
We then swept the roof down with a brush and positioned the liner at one end. I had bought a big tin of felt adhesive which we spread thickly in front the liner as it was carefully unrolled across the roof. All the time I was smoothing it down onto the OSB and pasting on more adhesive.
After I got to the end we went around the edge of the roof and pulled the liner down and tacked it under with roofing tacks. The corners were cut and tucked in neatly.
Finally the edge was held with lengths of roofing lat screwed back up to the 2x2. This made a solid edge to the roof.

Solid door frame.

<p>I figured the door frame should be as strong as possible. The doors were going to be quite heavy and the strain of use would put the concrete posts to the test.
Firstly we widened the opening by removing the bottom section of ring beam. I had bashed my head on this a few times and I was glad to see it go. Now we had a much taller doorway. The posts needed to be packed with a strip of roofing lat and then we fixed a length of 6x1 timbers to them using the same masonry screws as before. Fantastic fixings. A

The same 6x1 timber was laid across the bottom and screwed down into the base. This was slightly tipped forward with some packing and frame sealant. This would act as a sill and any water hitting it should run out of the shed. Next we ran 6x1 across the top and secured it to the timbers. The basic doorway was done.

Exterior Shuttering.

I was planning to clad the outside of the timber section in tongue and grove board. This should give a quality finish, but I figured it would be easier to mount the tongue and grove onto sheets OSB.
I had a good amount if OSB to use anyway and it was a simple job to measure and cut some pieces.
We fixed the peices to the outside of the shed with screws.
Next I marked out a straight line down the length of the roof with a string line and cut down with the circular saw. Front and back. We screwed on a length of 2x2 timber and a length of roofing lat down each side. This would give a good edge for holding the rubber roof down.

A roof over our heads.

It was very exciting fitting the roof boards to the rafters. The OSB boards were somewhat distorted and twisted so I had to sit on top pressing them flat whilst screwing them down.
No concern was given to the front and back edge as I was planning on running a saw down the entire length later. But they had to be fitted nicely onto the rafters and each fitted perfect snug up to the last. Our spacing was spot on.
To located the middle rafter which was always hidden we measured back 2ft from the edge of the OSB and set a chalk line. This showed us exactly where to fix the screws and worked great.
Before we knocked off we stretched out our rubber roof cover and clamped if down around the edges. This was done mainly to pre stretch it prior to installation and also to help keep out the rain.

On go the rafters.

The rafters were made from more of the 3x2 timber. The angle from front to back was very shallow so no bird mouth joints were required.
The lengths were measured and cut then screwed down to the upper ring beam using 4in screws. We set the gaps at 24in intervals so that it would be just right for the 8x4 OSB sheets to drop onto. Accuracy is important otherwise error would become compounded and the sheets require adjustment.
The rafters were attached narrow side down maximizing the strength of the wood.

A pent roof.

I had decided to build an extended pent roof. The extra height would dramatically increase the useful space.
To create a gentle slope from front to back we cut several 12in long sections of 3x2 and secured them vertically to the front ring beam at 3 foot intervals. Across the back ring beam we used  9in sections thus generating our slope. Approximately a 1:24 slope. I figured this would be enough to allow water to shed properly but not so steep as to require birds mouth joints for the rafters.
The lower ring beam was not entirely level so I adjusted the heights slightly and checked with a spirit level so when the upper ring beam was secured it  was level. 
I found the easiest way to fix these was to use little noggings of timber and 4in and 3in screws. Although noggings may not look particularly professional they do create a very stable and solid joint and can be made from your timber off cuts.
It is essential to drill pilot holes before fixing with screws, having a pair of cordless drills males the job much quicker, no swapping back and forth between drill bits and driver bits.
The upper ring beam was attached and we were ready for the rafters.

Strapping down firm.

I wanted to anchor the ring beam secure to the gravel boards. We drilled the the second row down and bolted a length of metal strap on. To keep the hole neat I drilled a small hole from outside in. Then a larger hole part way from each side. This avoided the possibility of it breaking out.
There was a small gap between the beam and the gravel board so I placed some pieces of thin metal to serve as packing.
Next we simply screwed into the beam and job done.
The plain stud end on the outside did not look unsightly.
A total of seven straps were installed and the ring beam was very secure.