The 20-foot (6-meter)-wide opening of the sinkhole is almost completely covered by the house and rescuers feared it would collapse on them if they tried to search for Jeff Bush, 37.
Crews were testing the unstable ground surrounding the home and evacuated two neighbouring homes as a precaution.
Hillsborough County Administrator Mike Merrill said heavy equipment would be brought in to begin the demolition today morning.
"At this point it's really not possible to recover the body," Merrill said, later adding "we're dealing with a very unusual sinkhole."
Jessica Damico, spokeswoman for Hillsborough County Fire Rescue, said the demolition equipment would be placed on what they believe is solid ground and reach onto the property to pull apart the house.
The crew will try pulling part of the house away from the sinkhole intact so some heirlooms and mementos can be retrieved.
Bush was in his bedroom Thursday night in Seffner a suburb of 8,000 people east of downtown Tampa when the earth opened and took him and everything else in his room. Five others in the house escaped unharmed.
Yesterday, the normally quiet neighbourhood of concrete block homes painted in Florida pastels was jammed with cars as engineers, reporters, and curious onlookers came to the scene.
At the home next door to the Bushes, a family cried and organised boxes. Testing determined that their house and another was compromised by the sinkhole. The families were allowed to go inside for about a half-hour to gather belongings.
Sisters Soliris and Elbairis Gonzalez, who live on the same street as Bushes, said neighbours were worried for their safety.
"I've had nightmares," Soliris Gonzalez, 31, said. "In my dreams, I keep checking for cracks in the house."
They said the family has discussed where to go if forced to evacuate, and they've taken their important documents to a storage unit.
"The rest of it, this is material stuff, as long as our family is fine," Soliris Gonzalez said.
"You never know underneath the ground what's happening," added Elbairis Gonzalez, 30.