Absolutely awful - do not hire.
I hired Sam to replace the shed roof and to replace a transparent perspex roof over a porch.
The work on the shed was completed, but I'm not convinced it will last 2 winters. The edged of the felt are not fully sealed and they did not replace the plywood as requested. This remains in place and rotten.
But the porch roof replacement was the biggest drama of all. First, the job was bodged with the multiwall polycarb sheeting put on falling in the wrong direction and it leaked terribly. Then after multiple failed attempts to fix it, he threatened me with returning and removing the whole job and leaving me without a roof.
Finally after talking him down, he came and finally fixed the leaks, which is the only good thing I can say about him.