Issues related to earthquake safety, bracing, or preparation.
Questions tagged [earthquake]
28 questions
15
votes
5 answers
How do I tell if my house is brick or brick veneer?
I live in a brick house, and am interested in understanding whether it is brick or brick veneer, as a way to understand what kind of risks it (and we) may face during an earthquake.
I hear that brick veneer is essentially a wood frame house with a…
John
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1 answer
What is the best way to drill anchor holes in a chimney?
A structural engineer who designed our earthquake retrofit instructed us to put 3/4 all-threaded-rod (ATR) through the chimney at the rafter line on either side of the chimney, back them with Simpson BP3/4-3's on the outside, and anchor them with…
KJ7LNW
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4
votes
3 answers
What is the correct plywood/OSB orientation for building a seismic shear wall?
We are building a shear wall by adding structural-1 plywood or OSB to the existing framing and nailing according to a nailing schedule. The wall is 13'x8'.
What is the best way to orient the plywood for the best shear strength and nail…
KJ7LNW
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3
votes
1 answer
Proper backfill for a trench dug below foundation level (within the 45 degree cone of support)
Given a trench dug below foundation level, what's the proper way to backfill? Here I'm talking about a trench below the bottom edge of an unreinforced concrete foundation built in 1950, supporting a 2 story stucco house. The trench is somewhat…
Bryce
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3
votes
2 answers
Are there span tables published for repairing a cut roof joist?
A roofing company mistakenly cut a 2 foot section out of a roof joist, on my home. I'm seeking a reference to what would constitute a proper repair, preferably a prescriptive code or a load table. I am aware of the American Wood Council tables,…
Bryce
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3
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1 answer
Securing heavy steel shelving unit (sitting on floor) to walls (earthquake prep)
I'm doing earthquake preparations. I want to secure two large, heavy, freestanding shelving units that sit on the garage floor to the adjacent walls.
The shelves are pretty thick steel (with particle board shelves), so they're very heavy and…
BillCord
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2
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What are the proper seismic retrofit techniques for a pier and beam home?
Context
I am conducting a major renovation of my home in Western Washington State, USA, and there are going to be seismic retrofit expectations concerning the foundation and mud plates when I get them inspected. Most foundation retrofit videos seem…
Bit Fracture
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2
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0 answers
What approach should I take when bolting our house to the foundation?
Our house is a four-square style over a concrete foundation, built in 1918. We're in the Pacific-Northwest, so we're thinking about hiring someone to bolt the house to the foundation in case of the Cascadia Subduction earthquake that everyone's been…
M -
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votes
1 answer
Why do the seismic straps need to go at least 4" above the controls on water heater?
I’m installing seismic straps on an electric water heater (48US gallon), and trying to follow the instructions.
there are two general instructions:
1 - place each of the two straps in bottom and upper third of the tank. this one seems self…
init_js
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2
votes
1 answer
Do panel sheathing clips make a shear wall stronger?
In another answer it was suggested that Panel Sheathing Clips between sheathing panels in a shear wall "will add a great deal of shear resistance at a minimal cost."
Is this true? If so, why?
I could be wrong and will be glad to use them if it…
KJ7LNW
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2
votes
2 answers
What kind of seismic concrete hold-downs should I use for floor joists over concrete?
Our existing floor joists and decking are over an 8" concrete foundation wall. The new work pictured below extends the existing 2x4 frames for more insulation space and we want to secure the new sill plate and original flooring to the concrete slab…
KJ7LNW
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2
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0 answers
How do I brace shed walls against shear when sheathing cannot overlap rim joist?
I'm building an 8' by 13.5' shed with a loft. I posted previously about the floor frame being slightly larger than the planned floor. Below is the intended floor framing, as seen in the plan:
Here is the current execution (joists have been…
fisherpeak
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vote
2 answers
Trying to secure a 100lbs floor mirror so it doesn't tilt over. is it possible to do this without a stud?
This wall is not shared by another tenant directly next door but does have a unit above me. I cannot find a stud. i have used a magnet stud finder. I have nailed a 2.5" nail into the wall in 1 inch increments. AND even though the rest of the…
Regi
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What are the acceptable retrofit methods for attaching an ambedded mud sill to my foundation wall in IEBC 2021?
I have a mud sill that was embedded in my home's foundation at time of pouring. Meaning, the top of the mud sill is flush with the top of the foundation wall. (More commonly, the bottom of a mud sill is flush with the top of the foundation wall.)…
Bit Fracture
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vote
1 answer
Seismic Retrofit - How to decide between more L70 or less L90?
Location: San Francisco Bay Area
Our house does not have a cripple wall. Plan A provides both L70 and L90 as options for floor connectors. Using L70 will require more work since we need to install more plates. Why would one want to go with L70?
ssgao
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