Right, time for an update on this:
It all came to a halt because I needed to get some new roofing on the building that the lean to is to lean against. It would be difficult to get to the gable end to reroof it after the greenhouse is put up.
Anyway, reroofed it last week, so on with the greenhouse.
If you remember from the pics from before, the building ( my workshop) is a steel shed sat on a 2 foot block wall, which meant that the back wall of the greenhouse would be old steel sheeting which is past its best.. so I decided to take off the steel sheet and skin it with plywood which could then be painted.
I went and bought the sheets yesterday, three 8X4 of OSB which is a cross between ply and chipboard, cheaper than ply and more robust than chipboard.......and then changed my mind......... The whole gable end right up to the roof will be dismantled and rebuilt with the same reclaimed bricks to match the greenhouse dwarf wall, not only that but a glazesddoor and sidelights built into the back wall so I can have a way through to the workshop and which will let light into that end of the workshop as well.
One reason behind the decision to have a door there is so that in winter it can be left open to get heat from the workshop, because my woodburner is only about 3 feet from the proposed doorway and it a decent output rated at 15KW . and in winter is left on overnight slow burn,
On the other hand, in summer I can open the door into the workshop and help to get cooling airflow through the greenhouse. Thats the theory anyway.
Another bonus of having a brick back wall as opposed to steel sheet or ply is that the mass of the brick will act as a heatsink, so even on a sunny winters day the heat will gain in the bricks and be released slowly overnight.
The roof of the greenhouse will be 8 foot to the eaves and another 2 foot plus up to the top wallplate, so I am going to get some auto vents from ebay, only £17 direct from China......
I am also working on getting power into there from the workshop, a couple of exterior grade double sockets, and a lighting ring in there as well.
and some speakers from the workshop hi fi as well ! Music is good for plants!
As for the floor, I am going to extend the block paving from the garden path up to and inside the greenhouse......
As for the OSB I bought, it will not be wasted. I will build a new henhouse from it, and paint it with masonry paint inside and out ....... Just an experiment..