Garage flat roof with a 1:40 fall. Dingle parapet

[Leebleez]

Hi guys. Im fairly new to chief but thought id get it to design a garage.

Ive built a basic shell which was nice and straight forward.

I now need to create a flat roof with a fall of 1:40 with a single parapet at the front.

Ive tried following the build a flat roof and build a parapet roof guide, however could really do with some help to do it.

I seem to end up with a hipped roof.

Cheers guys for any help.

Just trying to get planning in the uk and want to not involve an architect

[Evolution]

Check this tutorial out: https://www.chiefarchitect.com/support/article/KB-00295/creating-a-flat-parapet-roof.html