Outer walls going up without roof tiled

[GrantMcscott]

Due to scheduling and some of the roof not being able to go on as it rests on block work.  All the outer walls are being built out of block except one which is timber clad.

 

The frame has sat built for about a year and I am leaving 30 mm at the top instead of 20mm to allow for the additional weight from the tiles and more settlement.

 

will this be OK as normally you would tile the roof before building outer walls.

 

thanks