Fire alarm keeps going off when roasting in oven. Advice please? The problem started recently. I cook a lot and especially love baking cakes and roasting all sorts of vegetables in the oven. Recently when roasting, I noticed smoke coming out of the oven and the fire alarm went off. 

It was because a lot of grime and food drippings had accumulated (for over a year) at the bottom, and it was getting charred. The next day I cleaned up the whole oven (applying baking soda paste overnight then scrubbing with vinegar and steel wool). Except for the top of the oven which I simply can't get perfectly because that would require me to bend over backwards and clean, the rest is all squeaky clean. 

However now when I try roasting above 350 F, it still causes the fire alwarm to go off. There's nothing else in the oven that's getting burnt, even the veggies I placed in the oven weren't done completely. I am really puzzled. Any suggestions?
Make a cover for the alarm. Get velcro tape from a hardware store and attach one side of the tape to the alarm or to the ceiling. Then, make a cover out of foam rubber or whatever is convenient and attach the other side of the tape to the cover. Obviously, it needs to be airtight. Note that frames can be made by bending a coat hangar. Coat hangars can be cut by a chicken wire cutter, available at any hardware store.

When you cook, attach the cover and when you are done pull it off and put it away.