Smoke up? Brush down? Something else?

[Newbeeneil]

Fair point. I'll give some thought as to how I can seal stuff to the wall. This may be one job that duct tape just isn't up to.

James

When I had to seal a box against a wall to do a similar job I made an “adapter piece” as close to the profile of the wall as possible then filled the gaps with silicone mastic.