Interface between tiled roof and flat roof

[Daytonamick]

Hi There, this is my first post .... so please be gentle

I have nearly finished building a double dormer tiled with Marley plain tiles - one of the most laborious jobs in history. For the remaining pitched roof I used Marley Moderns. At the rear of the house the pitched roof interfaces with a flat roof.

There is a 40mm gap between the bottom of the last tile and the flat roof ... which is too small for another tile but too big to ignore ... should I use lead or is there a better (cheaper / less stealable) option

Thanks

 

[freddiemercurystwin]

I hear Zinc's very competitive!

 

[Alastairreid]

I hear Zinc's very competitive!

or this http://www.eurocell.co.uk/buildingplastics/lead-freeflashing.html