Fires burn faster, hotter. Buildings collapse more quickly. Fires can reach deadly “flashover” in less time.

The way houses are built these days — lightweight truss construction, gusset plates rather than nails, laminated wood — makes work more dangerous for firefighters than in houses with traditional construction methods of 30 or 40 years ago, fire Chief Jerry Myers told the selectmen.

“When a structure starts burning, we’re on a time clock,” Myers said.

Many fires can be contained, put out — the department does it regularly. But big fires can get beyond controlling.

If people have fled the burning building, they can often tell firefighters if others are inside or not.

“If we have no information at all, we have to assume someone’s in there, until a search proves otherwise,” Myers said.

Firefighters have to get the search done before the fire overwhelms the structure and roofs or floors collapse.

“Flashover,” Myers said. “Everything burns. Everyone in that dies.”

The fire chief spoke to the selectmen in two sessions — in December and in February — making the case for a new $725,000 pumper-tanker in the coming 2018-19 budget year, not next year as in the five-year capital spending plan.

The pumper-tanker could put a larger volume of water on a fire sooner. It would replace two other trucks, 17-year-old Engine 4 and 32-year-old Tanker 10.

“This vehicle will be smaller and more maneuverable than the existing tanker, which was not designed to be an attack truck,” the department’s budget says. “By reducing two separate use vehicles to a single dual use vehicle we will reduce the size of our fleet while increasing the fast attack capabilities of the department.”

The pumper-tanker was the department’s largest request in a 2018-19 town-school capital budget the selectmen hope to reduce from about $3 million to $2,750,000. The fire department’s proposed $4,504,000 operating budget would be a 2.16% increase over this year’s $4,409,000 — part of the $38-million town departments budget the selectmen will be reviewing next week.