P.s half sheets aren't light either

Use a very lightly damp...not wet...wash cloth textured rag.

You can get a cheap black light on amazon to find the problem areas.

If you can get cheap 1x12s, that's about right for this, or get a sheet of about 3/4" plywood and rip it into four 12" wide planks.It also helps to put some temporary lights up there while you're fooling around; that way you're not always dragging a drop light cord behind you. 

HI Paulette, go to the site wendypatton(dot)com  She has a free e-book on sandwich lease options that will shed some light on the subject.

Still could be something here and the mention of forming a general partnership, a possible master lease, or him forming some sort of charitable trust have been touched on lightly.

Around here landlords usually pay for trash pickup, and communal electric (hall and exterior lighting).  

If they don't have to use a loud window unit your tenant won't lose any more of the already limited natural light.

You receive the remaining ownership in light of your services provided to structure and manage the deal.

However, if the seller as a clause in their contract to allow to sell while under contract, then you have the green light!!