Rob Davis, 50, is co-ordinating a group of structural engineers from charity Search and Rescue Assistance in Disaster (SARAID) to assess hospitals and schools in three cities torn apart by the quake.
Mr Davis, from Bath in Somerset said his crew of former firefighters, paramedics and engineers will be examining buildings in Miragoane, Les Cayes and Jeremie to check whether they are safe to use and for anyone trapped inside.
Speaking ahead of his journey from the unscathed capital, Port-au-Prince to the affected region on the west of the island on Saturday, he said: “The figures of the affected and the injured people are quite horrendous.
Following the Mexico earthquake in the early 1980s where a hospital collapsed, premature babies were pulled out alive something like 25 days after the earthquake, so there are these miracle events
“I know the area well and the beautiful people of Haiti. Obviously there’s trepidation about what we’re going to see.
“But we train our people well, they’re prepared for this type of thing, and we just want to get on and get into the affected areas now.”
When asked whether he expects to find survivors, he said: “There’s always hope and there’s always a chance.
“There’s statistical evidence around the world of people being pulled out of earthquakes some days after.
“Following the Mexico earthquake in the early 1980s where a hospital collapsed, premature babies were pulled out alive something like 25 days after the earthquake, so there are these miracle events.
“As days go on, that window of survivability decreases. It depends on the condition of the casualties.
“If they’re not traumatically injured and they have access to water, there could still be people needing rescue.”
He added that five days after the 2005 earthquake struck in Kashmir, Pakistan, a man in his 80s was rescued from a building.
Mr Davis said: “He survived because he wasn’t traumatically injured, he was literally entombed in the building that collapsed on him, and it rained really heavily and had run down the walls of the building he was in.
“He was licking the rain from the walls and that kept him alive. So we’re not giving up hope.”
Mr Davis, who also rescued Haitians following the 2010 earthquake which struck Port-au-Prince, said the capital is only just “starting to recover”.
The epicentre of the 2021 quake was about 78 miles west of the capital, according to the US Geological Survey.
Mr Davis said: “The reports that we’re getting from the damage is quite widespread and we do have some significant towns affected, but it’s not as urbanised and not as widely populated (as Port-au-Prince).
“It’s a very poor country, it’s one of the poorest countries in the western world, and that’s before any earthquakes.
“Poor old Haiti has had a catalogue of disasters with floods, earthquakes, cholera outbreaks, so the people are very resilient individuals and communities.”
The SARAID team led by Mr Davis are due to stay in Haiti for eight days on their rescue mission.
Haiti’s Civil Protection Agency on Wednesday said the death toll was 2,189 with 12,268 people injured. Dozens are still missing.
It is estimated that more than 200,000 people died amid the quake in 2010.