There are two primary types of security bars: one for standard doors and one for sliding patio doors. Look for a security bar with a patented locking device that can withstand up to 1,000 pounds of force. Patio door security bars should also prevent thieves from lifting the door off the track.
Most exterior paints will cover about 400 square feet per gallon for one coat. But adjust for waste factors like the type of surface and equipment used. If the surface is rough or porous, add 20% to the total gallons figured. If siding is narrow (4 to 5 in.), add 10%. If on a corrugated surface, add 33%. Also add on a 10% waste factor if using brushes or rollers, add 20% for airless paint sprayers, and add about 40% for air paint sprayers.