Why do you think you need a reroof would be my first question?
What tiles do you want: will the existing roof structure carry the load if they are heavier than existing. What materials are to be used for flashing and vallies. Soffit, faschias and gutter done at same time? Provision for fully...
It's steel with a thin coat of protective zinc which is what galvanising is. It's 100% safe unless you want to weld it as the fumes are nasty, but it will be heavy and may well not fit the access: they;re often put in and built round.
Unless you've got a point load over the opening (which does not appear to be the case), 65x100 will be 100% fine. The rafters won't be carrying much load due to the presence of the outrigger.
There's no difference surely to the ties that are aready there regarding heat loss and we tend to put more ties in these days than years ago ebven though heat loss is a much more important consideration
Debris from drilling into a celcon block which is a high percentage air ain't going to be a...
The one I used was a Villiers, knotted rope to start.
I seem to recall having to rotate a short slotted cylinder on the air intake which acted as the choke and jiggling a button on the float chamber to prime it before trying to start.
We had a sprayer and a saw bench as well as the cutter...
I find the most important thing is to pack the first row so it's absolutely solid when you come to push in the second. I got a pack of adjustable flooring packs from Toolstaion which make the job very easy.
Check eack board carefully all round for damage before you try to fit it: even a small...
See my post 2. It's a fancy shed at the end of the day and it's never going to get the snow load allowed by TRADA tables.
If you're really, really worried close 'em up to 300 crs. This will provide the same strength as notional 67mm wide timbers at 400 crs. TRADA lists 63s as ok to 3.1 clear...