Any way to seal the top of a thin wall?

[roachbug]

Is there any way to seal the top of a thin wall??
https://app.box.com/s/1hnidxcybcn54sf7ufbby1ta8dh3jo9r

I have tried to increase outline overlaps, top solid layers.

Any suggestion??

[JoeJ]

Try printing with 1 outline perimeters. You could also try modifying your extrusion width to make it a tiny bit wider, since that would easily make the walls a perfect multiple of your extrusion width and fill it perfectly.