Sparks were flying on the first floor of Petaluma’s old brick silk mill Tuesday afternoon as construction crews took advantage of a rare dry day to make progress on its conversion into a boutique hotel.

The historic brick building at 450 Jefferson St., built in 1892 and granted national historic landmark status in 1986, is on its way to its latest incarnation, this time as the 76-room Hampton Inn Petaluma.

The wet winter forced the developer, BPR Properties, to revise plans for a spring 2017 opening. Now, said Perry Patel, a partner with BPR Properties, they’re looking at September.

“With wet weather, it’s hard to do work on the roof — it’s hard to do anything — and the weather hasn’t let up,” Patel said. “I think we’re getting close to buttoning up the building, any roof leaks, as much as possible.”

Eventually, the hotel will feature a beer and wine bar in what had been the dye house, which will also serve as a breakfast room for visitors to enjoy a complimentary breakfast. There also will be outdoor seating and a fitness center.

Other properties in the Palo Alto-based BPR Properties portfolio include the Hotel Shattuck Plaza in Berkeley, Hotel Keen in Palo Alto and Hotel Paradox in Santa Cruz.

BPR Properties decided to turn the Petaluma Silk Mill space into a Hampton Inn rather than an independent hotel because “it allows us to have a nationwide pipeline,” Patel said. “I think having that brand is going to give an assurance to guests. The Hampton brand allows us to target the business clientele that’s coming to the market.”

Once completed, the hotel’s charm will lie in details that are specific to Petaluma, as well as BPR’s commitment to reuse as many materials original to the building as possible. Walls hung with photographs of Petaluma will abut original brick walls. Windows, designed to look like what would have been installed in the original mill, will be hung with shades with maps of Petaluma on them.

Most recently, the silk mill was home to Sunset Line & Twine, which closed down as a cord factory in 2007. Since then, the building has sat vacant, an occasional home to transients and the target of vandalism and graffiti — some of which can be found scrawled on beams in the building’s north tower, where markings of newer vandals keep company with signatures of vandals past. One scrawling dates back to Jan. 22, 1927; another to 1940.

“From our perspective, it’s about retaining the charm of this building, the characteristics of it, as much as possible,” Perry said. “Anything we’ve actually touched in order to retrofit it, from a seismic perspective, has been replaced with materials that mimic the original condition to the best of our abilities. Whether that’s the mortar between the bricks or the bricks themselves, we have tried to capture as much of the original look as possible.”

You can reach Staff Writer Christi Warren at 707-521-5205 or christi.warren@pressdemocrat.com. On Twitter @SeaWarren..