The two-alarm blaze happened on the 400 block of North 16th Street, AFD said. Units battled the blaze from the building's rear off of Warren Street and from the roof, firefighters explained.
Pictures and videos from the scene showed heavy fire and smoke damage.
No injuries were reported by first responders.
Twelve residents received assistance from the Red Cross of Greater Pennsylvania, the organization said.
Click here to follow Daily Voice Conshohocken-Plymouth Meeting and receive free news updates.