bolting and retrofitting

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From the photos in this link, does this mean my home is considered "bolted to the foundation" ? http://s1163.photobucket.com/albums/q548/cegarbage /
I have had a home for 10 years, built in 1948 in the La Crescenta area of Los Angeles. It survived the Sylmar quake and Northridge quake (both @ 20 miles away) without any problems
With the type of coverage CEA offers, I'm re-assessing whether or not I really want to pay the premium.
Thanks!
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On Thu, 23 Feb 2012 13:28:21 -0800 (PST), Craig E

I don't know what CEA is but I gather you mean for earthquake insurance??? I'll assume you mean this and in that case the bolts you have to hold down the wall are not considered hold down bolts for earthquakes. Google hold downs for earthquake design and you will see they are much heavier duty. If it matters, a long time ago I designed some California apartments with hold downs / tie downs for earthquake design. I think I had to design shear walls too for that apartment. Sorry I don't remember the name or location of it because it was back in the 80's.
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Nope...
Those are standard sill plate bolts...
Seismic bolts are much larger in size, aren't simply straight or curved like typical J-bolts, (they are longer S-bolts to resist pulling out) and would be installed with a larger metal plate instead of a normal bolt washer again to prevent pull out...
Also, simply bolting the sill plate down doesn't provide all that much in the way of seismic protection, the wall studs need to be tied into the foundation as well using tie downs like the other reply said...
~~ Evan
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Bob:
His house IS NOT bolted to the foundation if considering *ANY* kind of seismic building codes is a factor...
The pictures the OP linked to show standard sill plate attachment to a non-seismically rated structure...
PERIOD...
I know more than enough about construction to answer that question... The bolts pictured in the photos provided by the OP will disengage if the structure is subjected to locally significant seismic activity...
Since the OP asked his question in relation to the CEA regulations, which others here have presumed to be in reference to some sort of insurance premium issue, the answer to his question is NO... His home is built to non-seismic construction standards and would not withstand local seismic activity...
Referring to past earthquake events and making the claim that "well the house was here since 1948 and wasn't destroyed or seriously damaged in any of those earthquake events" shows a lack of understanding as to what the seismically enhanced building codes are seeking to accomplish -- protection of people and property in the event of local activity...
It is sad that you snapped a judgement against my understanding of the seismic codes when you seem to have not even understood the OP's question to begin with...
~~ Evan
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Sorry Evan but you don't know what you're talking about................. and you are using terminology without sufficient technical background

Wrong again!
"the bolts pictured in the photos provided by the OP will disengage if the structure is subjected to locally significant seismic activity"
Those bolts will do the job for which they were intended..... just fine. Whether or not the rest of the "load path" is up to the task is another question.
Ok "knowledgeable one", how significant must this "local seismic activity" be?
Careful, this is a trick question to expose your lack of knowledge.
btw it is you who misunderstood the OP's original question..... because I understand the context in which it was asked.
This might give the answer to the trick question but "what the hell", if you want to learn, check out
http://www.seismic.ca.gov/pub/CSSC_2005-01_HOG.pdf
Especially pages 2, 14 & 15. The section on cripple walls is useful as well but the OP never said whether his home had them.
The whole thing about evaluating the potential for e/q damage in older homes & agreeing upon a reasonable set of upgrades, rests on not "what is the absolute best course of action" but "what gives the most bang for the buck and what will an owner reasonably do".
Over the years it has been agreed upon that, for older homes, the following upgrades make the most sense.
Quick, cheap & easy DIY ones :) strap water bolt house to foundation sheath cripple walls
Not so cheap & easy retrofit pier & post foundation URM walls URM chimneys
notice there is no mention of hold downs........ those are for new construction or MAJOR retrofit or repair situations.
I know there is very little likelihood that you have this sort of in depth knowledge or experience.
"seismically enhanced building codes"..... reveals you lack of knowledge; spoken like a true amateur, a wanna be
May be it's my 20+ years in the CE/SE world being involved in construction, testing & research that gives me the basis from which I speak? :)
Evan, posting your CA contractor's license number (if you have one) won't change my opinion of your knowledge. If you have a CE or SE....please DO NOT post the number, as I will be obligated to report you to BORPELS as practicing without suffice knowledge to do so.
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20+ years experience and you still waste your professional time on Usenet spewing poor advice...
Stick to paperwork and static testing under the most ideal conditions in a structural materials lab...
Since you are a CE or SE (Engineer) you have ZERO ability to actually build something, you interpret the plans and supervise (wait for it) the paperwork... You get approvals from people who aren't engineers who visually inspect the work after its completed... Hmm... Who to trust, an engineer who says something is safe after seeing a handful of pictures of something and nothing else, lacking any sort of situational awareness of other hazards OR someone who points out that the older home even if bolted to a foundation would still pose a life safety hazard to the occupants during an earthquake event...
Want to talk about "reckless practice" shove your professional ethics deep up your ass and rotate on them... Don't open your mouth (or use your fingers to type) when you are bound by professional standards and you lack anything more than a causal glance at the facts of a situation...
Mr. Engineer, how may homes suffered significant damage/total loss/fatalities even when bolted to their foundations because the studs detached and the structure still failed... Bolting alone really offers no more actual protection as the building will shake itself apart if it is close to the epicenter or in an area with other hazards which can be triggered by a far away earthquake...
Wow,. you must be psychic or an omniscient all-knowing-being to say with such certainty that the OP's home is anything in any significant way without doing the proper background research and a physical on-site inspection...
Good luck with your "work" and "career"...
~~ Evan
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On Sat, 25 Feb 2012 07:49:53 -0800 (PST), Evan

Evan, he's laughable so he's not all bad. I believe the OP wanted to know if the CEA would find the original bolts acceptable and while I think not, only the CEA can answer that. What some fail to realize, the guideline is just that, a guideline not a standard to determine if you house can resist an earthquake. Further the guideline doesn't say to what forces the bolts need to resist so while they can resist something, the question is whether the CEA criteria will be satisfied.
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Did oyu even read the referenced docs?
"I believe the OP wanted to know if the CEA would find the original bolts acceptable"
CEA only wants a "Yes" or "No" answer to the existence of the bolts.
You have no idea what the CEA wants to know because you are wrongly focused on the code. This is not a code question.
It is a question about the existence of the bolts in the OP's home.
Looking at the photos..... does the OP's home have bolts?
There is no question from the OP or the CEA about the adequacy of them. CEA assumes that if they exist they were installed per the practice of the time.
"Bolts" vs "no bolts" makes such a huge different in e/q performance that being "bolted" is enough information.
Take a look on the web for photos & commentary about home damaged in the 1987 Whitter e/q. That's what motivated the concepts in the retrofit pamphlet.
If you want to learn more reseearch LA Division 88
Put your ego aside & learn something.
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Evan-
you depariage my reference to
|"Referring to past earthquake events and making the claim that "well the house was here since 1948 and wasn't destroyed or seriously damaged in any of those earthquake events" shows a lack of understanding as to what the seismically enhanced building codes are seeking to accomplish -- protection of people and property in the event of local activity... "
So, ifI have a structure of unknown capacity and I load it to an approximately known level and it shows no distress..... I have gained no knowledge of its capacity?
It's not about "the paperwork", it's about the current condition of the structure and its history.
Think about it.
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No sir, it is not, the building code is concerned with all seismic events, including one which might happen down the street -- not just the ground vibrations which *could* shake a house off its foundation (unlikely) from an event occurring tens of miles away...
High winds could also blow an unattached house off its foundation, which is why there are provisions which increase the minimum building standards in areas prone to such weather phenomena...
The OP's house is clearly not up to any sort of modern seismic code... PERIOD... The way his house is bolted to the foundation would not do anything to protect the integrity of the structure during a local seismic event...
Stating the history of the house and saying it is still in existence and undamaged is totally pointless, as it will NOT remain in that condition if a fault line in the OP's neighborhood is the next area of activity...
The building codes look at the techniques of the past and the mistakes which were made that resulted in loss of lives and property to ensure that future buildings won't fall prey to those same issues...
Houses can be attached to foundations with bolts, however those bolts offer no protection against serious local seismic activity or against landslides which also tend to be a problem in California whether triggered by rainfall/flooding events or during an earthquake...
I stand by what I said, the OP's house *IS NOT* attached to the foundation in a way which will offer any sort of earthquake protection during an event which occurs locally, his life and home are at risk the way the structure is currently put together...
You seem fine with giving the OP a false sense of security for whatever reason... The context of the question asked was very vague but clearly the answer given the totality of the circumstances (considering all factors and sub-plots) is NO... No, as far as offering anything more than "the house will break apart before becoming detached from the foundation" because there are no shear walls or structural tie downs in a structure that old to hold the building together as the ground moves around underneath it... No, in so far as meeting any standard of seismic protection which would be required during any substantial renovation of the structure... No in complying with any version of the CEA codes currently in effect...
~~ Evan
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And of course that isn't the issue. He simply asked if his house meets the definition of "bolted to the foundation".

Apparently the California earthquake authority disagrees. Did you bother to read the reference?

More drama from Evan as usual.

As has the CEA, did you read their document? The current building code for a NEW building isn't the question being asked.

Again, the CEA clearly disagrees, but you didn't bother to read that, did you? You have a reference that says bolting that you would find in a typical house anywhere in the USA offers no benefit?

Who should we believe? You or the CEA?

You seem fine with handing out opinion without regard to the facts. And making alarmist mountains out of mole hills. You want to tell us again how it's illegal to vent nitrogen to the atmosphere?
The context of the question asked was

According to the CEA, which the OP himself referred to, the answer would appear to be Yes.

There you go again. Just like the robot from "Lost in Space". Arms flailing, "Warning! Danger Will Robinson!" And just as clueless as ever.
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On Sat, 25 Feb 2012 07:21:58 -0800 (PST), Evan

Evan, first off, we are in agreement except that you are wasting your time replying to this guy. He won't accept what you say no matter how nice you put it. He boasts how much he knows tho... which I find laughable. I will say only one nice thing about him and that is he gave me a nice chuckle before I went to bed last nite reading his silly posts.
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SNIP
Doug-
The fact that you agree with Evan should be a red flag.....
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wrote:

Bob:
His house IS NOT bolted to the foundation if considering *ANY* kind of seismic building codes is a factor...
That is why it survived ************************
The pictures the OP linked to show standard sill plate attachment to a non-seismically rated structure...
PERIOD...
I know more than enough about construction to answer that question... The bolts pictured in the photos provided by the OP will disengage if the structure is subjected to locally significant seismic activity...
Since the OP asked his question in relation to the CEA regulations, which others here have presumed to be in reference to some sort of insurance premium issue, the answer to his question is NO... His home is built to non-seismic construction standards and would not withstand local seismic activity...
Referring to past earthquake events and making the claim that "well the house was here since 1948 and wasn't destroyed or seriously damaged in any of those earthquake events" shows a lack of understanding as to what the seismically enhanced building codes are seeking to accomplish -- protection of people and property in the event of local activity...
It is sad that you snapped a judgement against my understanding of the seismic codes when you seem to have not even understood the OP's question to begin with...
~~ Evan
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SNIP
Grumpy-
I do not understand your post
That is why it survived ************************
?????
Did you read the entire thread? Did you read the referenced docs?
The OP's question .....to reiterate for the umpteenth time. :(
.............. From the photos in this link, does this mean my home is considered "bolted to the foundation" ? .......
The answer to which is "yes".
The OP asked nothing about "considering *ANY* kind of seismic building codes is a factor... "
Take a look at the multiple reference docs.....
When doing an eval of an existing home (like the type of eval that CEA has the homeowner do for an insurance premium estimate) one of the binary (yes / no) evaluations is ....
bolted vs not bolted
the existence of bolts puts the house in the "bolted category"
The reason for such a simple delineation is.....
Bolted homes (even minimally bolted per 1940's code) perform SUBSTANTIALLY better than "not bolted" homes. Take a look at the SFH damage by 1987 Whitter e/q.
Homes "not bolted" were often total losses. Homes "bolted" typically suffered minimal damage.
It's like seat belt vs no seat belt ..... not ..... 1971 seat belt vs 2005 seat belt system It's like parachute vs no parachute .... not ..... 1948 parachute vs 2000 parachute.
The context of the OP's question is what drives the answer. :)
cheers Bob
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wrote:

You are taking his question out of context. He wants to know if CEA will consider it bolted to the foundation. Of course in the pictures, it is bolted but that's not really what he wants to know. I believe CEA is some sort of earthquake insurance (correct me if I'm wrong) and therefore they will have some standards they go by to decide if it can withstand an earthquake of a certain intensity (again defined by their standard). If they feel it can withstand this force, they will consider it bolted, if not, then not adequately bolted to meet their standards in order to insure the home. One of the URLs furnished in this thread clearly states that the bolts have to be installed correctly to be considered effective. I can tell you that 1940s standards are not as stringent as the current standards for earthquakes so my guess is CEA will say it's not adequately bolted. Again, I agree it's bolted but not necessarily to meet CEA standards. Of course let the CEA speak for themselves. I wish the OP would call them and inform us what they tell him so we don't have to go back and forth here.
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Doug;
Do you live in California? I do.
I know what the CEA is. Do you? Do you go to the CEA website & try their premium calculator? If you did, you should have an understanding for the context and oyu'd know what CEA is.
Their 'standard' is "bolted vs not bolted"......... it's a binary thing (& don't play the game.... "if the house had one bolt, would it be consider bolted")
All the CEA cares about is "bolted per the standard of when the house was built or retrofitted........1/2" at 6' for one story or 5/8" at 4' for mutli. It aint rocket science. Mud sill anchor bolts have a LOT of shear capacity, their presensce will keep a house on it's foundation.
I challenge you to find an example of a SFH (single family home) that was bolted (per the standard of its day) that was shaken off its foundation in the 1987 Whittier e/q. I select Whittier because of the high number of older homes in the area. And the fact that Whitter e/q was a major motivation for the content of the docs I posted,
A 61 Corvair isn't a 2005 Corolla but you're a a LOT safer a roll over in either IF you're using the seat of the day than in a 54 chevy without a seat belt.
I can I possibly correct you? You don't think I know what I'm talking about.
Yes, the bolts need to be correctly installed but don't you think the 1940 bolts were CORRECTLY installed at the time they were installed?
Notice your choice of words .....
"I believe CEA is" "some sort of earthquake insurance" "my guess is CEA"
There's a lot of wiggle room in those weasel words" And you have yet to refute my argument with logic.
How about you call them? There's even a toll free number.
California Earthquake Authority 801 K Street, Suite 1000 Sacramento, CA 95814
(916) 325-3800 Toll-free (877) 797-4300 Fax (916) 327-8270
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wrote:

Thanks but let the OP call them and report back his findings. Maybe what you said is correct or maybe not. Let the OP tell us. There is more to bolt strength in concrete than spacing between bolts but maybe CEA does or does not care about this. I do agree the house probably was built to the 1940 stds.... no argument.
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"Maybe what you said is correct or maybe not."
Well that is certainly true.....
"There is more to bolt strength in concrete than spacing between bolts"
Yeah, like...... concrete strength, bolt diameter, bolt strength, embed depth, edge distance........actually you have to get the bolts pretty close together to negatively embedded bolt strength (group effect). The wood would be the limiting factor wrt to bolt spacing WAY before the concrete.
The only thing the CEA cares about is "bolted" or "not bolted".
Why not call the CEA and confirm or deny my "theory"?
cheers Bob
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wrote:

Bob, I've designed a lot of bolts within foundations in my time for the Petro Chem industry as well so I think I understand their behavior well. If the CEA doesn't seem to care about their behavior in concrete, then that's their problem. I don't care to do the work for the OP. Let him call them since it's his question to start with.... I have other problems that need my attention.
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