Redlands old homes vulnerable in large quake

Oct. 07--REDLANDS -- Houses built before the 1930s -- specifically turn-of-the century Craftsman and Victorian homes in Redlands -- are most vulnerable to a big earthquake.

Jim Bacca, owner of Professional Property Inspections in Redlands, says over the past 30 years he has inspected most of the old houses in town. He describes a typical 100-year-old Redlands foundation as river rock loosely held together by crumbling mortar.

"They just went down to the Santa Ana and got of a bunch of river rocks and mortared them into a wall and built their houses on top of them," he said. "For what they are, they performed decently for a long time. The issue with that is the mortar being wet over the winter, and people not controlling their irrigation water, the mortar deteriorates."

He's seen it under many historic homes in Redlands.

"If you crawl under the house you'll see piles of mortar dust. The mortar that was holding the rocks together, you know -- dust to dust we came and dust to dust we go," he said. "There are many houses you can just go and remove rocks, you can remove bricks, you can see gaps, you can see daylight from outside."

Building codes changed after the Long Beach earthquake in 1933, requiring wooden structures to be bolted to the foundation. Bolting is the No. 1 thing that increases seismic stability, Bacca said.

He estimates that only 15 percent of old houses in Redlands are bolted.

"In the Big One, the character of Redlands could be in a shambles," he said.

Redlands contractor Jeff Bonadiman is a seismic retrofitter. He reinforces old-homes' foundations with concrete and then bolts the structures to the foundation.

He demonstrated how the old mortar falls away "like sugar" by rubbing it lightly with a pencil eraser under a Craftsman heritage home on Alvarado Street that he was about to retrofit.

"I've seen houses where you'd wonder how it was still standing," said Bacca. "It's not like the entire house is likely to go sliding into the street like you see in movies, but if you have a house where a corner of it drops a foot, that is a big repair. You just don't go have Johnny lift it back in place. Plus you have issues with the interior structure, plaster, plumbing.

"There are certainly lots of old houses in downtown Redlands where that could happen."

Because Bacca's inspections are primarily done as part of the home-buying process, he sees the market for heritage residences in Redlands.

"When people in Redlands are buying older homes, it's because of the charm of them, the nostalgia, the whimsy of them, " he said. But "in terms of seismic strength, there is no comparison between those and what's being built today."

Bonadiman says there are some ways old homes have a structural advantage:

"Some say newer buildings are typically safer than older buildings due to more advanced building codes. This is not always true. For example, older houses were commonly built with old-growth lumber, which is of higher quality than new lumber. Old-growth lumber is stronger, drier and more durable, making it less prone to warping and cracks. Also older houses were built with a higher quality of workmanship."

But the foundation isn't one of those ways.

"After 50 years or so things do start to fall apart, especially the old unreinforced masonry foundations," Bonadiman said. "The life years of mortar is 25-plus years."

Seismic construction advances every time there is a large quake.

"We know from monitoring earthquakes around the world what things are best performing and what things are not so good performing," Bacca said.

One of the things Bonadiman said we learned from the 1994 Northridge earthquake is that more people are injured by things falling inside the home than from buildings collapsing.

He also said many home owners of older homes are choosing to retrofit rather than pay for earthquake insurance.

It's an investment in security, not a financial investment.

Bacca said a retrofit won't pay for itself in home value, but gave an example of a young mother with her two babies moving into a Heritage Home and wanting a sense of safety.

"It's more valuable in an emotional sense than as a selling point," he said. "If you have two houses on the market next to each other and one has had a $20,000 bolting retrofit, obviously the one that's had the work done will be preferable to the buyer, but the appraiser will not add $20,000 to the value."

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