Never secure a building unless certain raccoons are gone.
Preventing Access to Structures
Tree Branches.Trim back tree branches--Raccoons prefer to use tree branches to access buildings and structures.
Porcupine Wire. Install porcupine wire around corners and downspouts. Ideally it should consist of three rows, with 1" of space between the tines of each row. Caution. Make sure the porcupine wire is placed at least 9 feet off the ground to prevent accidental injury from someone leaning against the building or structure. The tines are VERY sharp.
Electric Fencing. Electric fencing is an option provided your community permits such a device.
Preventing Entry
Gable Vents. Secure 1/4-inch hardware cloth on the exterior of all attic vents. Apply screws (with washers) to the corners and mid-points coupled with staples.
Paint mesh prior to installation if aesthetics are a concern. Most people don't even notice mesh installed above the first floor.
Mushroom Vents. Mushroom vents are best secured by installing a stainless steel screens over them. (See photo at right)
Alternative Way to Secure Gable and Mushroom Vents. Gable and mushroom vents may also be secured from the inside of the building; but this is not preferred. Vents secured in this manner still permit the vent to be damaged and the mosquito netting to be broken thereby requiring repair. WARNING: Make sure the mesh will not interfere with any fans, particularly exhaust fans as the fine mesh may collect dust/insulation and restrict airflow. Mushroom vents secured from the inside also run the risk of creating a platform for nesting squirrels. Details on securing vents see Gable Vent Screens
Decks, Porches, and Sheds. Install trench screening BEFORE you begin to have a problem. See Trench Screening
Sign
Raccoon
prints in powder Description: shows use of tracking powder to get prints Photo Credits: Kirk LaPierre, A1 Saver Services@www.a1saver.com
raccoon
paw marks on the down spout--This is a common way raccoons gain access to house roofs. Raccoons are exceptional climbers for their size. Photo Credits: Kirk LaPierre, A1 Saver Services
@www.a1saver.com
A raccoon only needs a 4 inch diameter hole to enter a structure.
Chirping sounds emanating from the fireplace, typically in the Spring, are a classic sign of raccoon young.
Damage
Raccoons will kills poultry; eats sweet corn, other garden & truck
crops, pet foods, pets; rolls-up turf sod; damages shingles, fascia boards;
Raccoon
in garbage Description: shows raccoon exiting dumpster of garbage Photo Credits: Kevin Clark
Raccoon
roof entry. Note how the raccoon removed asphalt shingles and wood sheeting to enter through the building's roof. Photo Credits: Kirk LaPierre, A1 Saver Services
@www.a1saver.com LaPierre
raccoon
damage to wood soffit. Note how it looks torn out which is characteristic of raccoon activity. Squirrel damage would show gnaw damage. Photo Credits: Kirk
LaPierre, A1 Saver Services@www.a1saver.com
Secure all chimneys with professionally manufactured chimney caps to prevent raccoon entry to chimneys. Capping also helps to protect the chimney crown and prevent other animals from entering the chimeny. Photo by Dallas Virchow.
Secure trash cans inside buildings or wire lids down.
Repellents
Female raccoons have been repelled with coyote urine and professionally manufactured materials. These products work best to convince a mother raccoon to take her young elsewhere.
Otherwise, repellents are not effective on raccoons.
Trapping
Footholds; #1 Longspring, 1.5 coilspring
Bodygrip; 160's through 220's.
Cage Traps; 10x12x32 single door trap would be a minimum size. Cage trapped raccoons, that are released, are very difficult to capture again. Even if translocation is legal in your area, think long and hard about the wisdom of doing it.
Specialty traps; Egg trap, Little Griz, Duffer Trap
Raccoons are increasingly very comfortable around people making them an active vector of disease transmission to humans. Not this raccoon near door acting relatively tame. Photo Credits: Kevin Clark of Critter Control.
Scientific Name:
Procyon lotor 
Trim back tree branches--Raccoons prefer to use tree branches to access buildings and structures. 
Mushroom Vents. Mushroom vents are best secured by installing a stainless steel screens over them. (See photo at right)
Raccoons will kills poultry; eats sweet corn, other garden & truck
crops, pet foods, pets; rolls-up turf sod; damages shingles, fascia boards; 
raccoon
damage to wood soffit. Note how it looks torn out which is characteristic of raccoon activity. Squirrel damage would show gnaw damage. Photo Credits: Kirk
LaPierre, A1 Saver Services@www.a1saver.com 
Raccoons are increasingly very comfortable around people making them an active vector of disease transmission to humans. Not this raccoon near door acting relatively tame. Photo Credits: Kevin Clark of Critter Control. 
Ringtail
cat in cage Description: shows Ringtail cat in cage
trap--illustrates all raccoon family suseptible Photo Credits: Wes
Patrick