Dormer roof construction

[chilluk]

We are two weeks into a loft conversion and the main dormer structure has started to take shape. When I went up at the weekend the roof has been covered in what looks like the flooring chipboard with some fabric over it held down by battens.

I am assuming this is a temporary covering as the plans state 18 mm marine ply, and will ask the builder when he's back on site tomorrow. I just wanted to be sure I should be enforcing the ply as per plan and that there were concrete reasons for using that and also for not using the chipboard?

The work so far seems good and neat but this just concerned me a bit.

 

[mointainwalker]

If the plans state marine ply and you're paying for it ( chipboard significantly cheaper ) then that's what you should get, Suppose this work is subject to BCO and he will want to see what has been approved is what is installed..

You should realise that it is not you who needs to be hesitant. If the builder is altering agreed specs without consulting you, he is behaving unprofessionally ( suppose could be called fraud - agreeing supply of one thing, delivering something else ) or worse.

 

[big-all]

may well be temporary to allow a watertight roof do they look perinant!!!

is there any sheets off ply lying about!!!