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Bay Area Retrofit
United States
เข้าร่วมเมื่อ 9 พ.ค. 2014
Bay Area Retrofit was founded 25 years ago and to educate the public made these 90+ videos. They look at every aspect of home seismic retrofitting both for the homeowner and the contractor. The author was trained by the best seismic retrofit engineers in the country has been on two national committees that developed seismic retrofit building codes.
Learn how to identify weaknesses in your home and what to do about them. We look at homes with cripple walls and houses without cripple walls. We look at homes built before 1940 and homes built after 1940. We look at hillside homes, and we look at soft-story homes with a living area above a garage. We also look at homes that have every weakness imaginable
Contractors and engineers will enjoy technical topics such as shear wall construction, the impact of wood species, the differences between the three types of bolts, etc.
Learn how to identify weaknesses in your home and what to do about them. We look at homes with cripple walls and houses without cripple walls. We look at homes built before 1940 and homes built after 1940. We look at hillside homes, and we look at soft-story homes with a living area above a garage. We also look at homes that have every weakness imaginable
Contractors and engineers will enjoy technical topics such as shear wall construction, the impact of wood species, the differences between the three types of bolts, etc.
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ABRIDGED EARTHQUAKE RESISTANCE OF STUCCO
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ABRIDGED EARTHQUAKE RESISTANCE OF STUCCO
ICC 1300 The Simpson URFP and FRFP Bolting Hardware
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This is a comparison of a Simpson URFP and FRFP found in ICC 1300 and shows one more reason why ICC 1300 is so expensive tinyurl.com/ICC-1300-P-1100-Cost This video was a presentation to the ICC 1300 code committee which used the terms "Type C Connector" for the URFP and the term "Type B Connector" for the FRFP. The purpose of the video was to show the other ICC 1300 code committee members exac...
ICC 1300 Retrofits: Stucco Versus Wood Cripple Walls
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ICC 1300 requires large quantities of hardware and plywood for heavy homes that have stucco siding and/or plaster. Based on my research stucco homes are far more resistant to lighter homes such as those with wood siding. The photos seen in this video say it all. This is another reason ICC 1300 retrofits of stucco home are unaffordable tinyurl.com/ICC-1300-P-1100-Cost I looked at approximately 5...
ICC 1300 Versus Contractor Methods
มุมมอง 627 หลายเดือนก่อน
The video compares ICC construction details (instruction on how a contractor should build something) with the ways contractors actually do it. This will also make clear one more time why ICC 1300 is so expensive tinyurl.com/ICC-1300-P-1100-Cost These videos should show you how contractors who face engineering challenges address them in the most practical and cost effective way with methods and ...
ICC 1300 And The Crazy T Block Detail
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ICC 1300 used to have a construction detail that by all engineering standards defies the rules of logic and increases cost tinyurl.com/ICC-1300-P-1100-Cost It illustrates how some members of the original ICC 1300 predecessor FEMA P-1100 committee had only minimal understanding of how shear walls work. Fortunately, when I and more qualified engineers on the ICC cripple wall retrofit subcommittee...
How to read the tables in ICC 1300
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ICC 1300 is not very user friendly. I have been a seismic retrofit contractor for over 25 years and even I found it confusing. It looks more like a series of tables, graphs, and drawings that an engineer would use rather than something a well informed and experienced contractor would use, let alone the average homeowner. ICC 1300 residential retrofits are found in the proper use of its tables i...
ICC 1300 Ignores Additions And Destroys the House
มุมมอง 387 หลายเดือนก่อน
ICC 1300 is a seismic retrofit guideline; which means if "retrofits" homes that did not have certain earthquake resisting components when they were built. Invariably this means these are older homes which over the years often had additions, sometime more than one addition. ICC 1300 neglects ignores this fact to the point that one can apply all the provisions found in ICC 1300 and end up with a ...
ICC 1300's Ineffective Floor Connection
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ICC 1300 was codified out of FEMA P-1100 in which there was not one single contractor among its authors. This video makes it abundantly clear that relying on the practical sense of an engineer to design something versus years of experience found in the construction industry really does not make any sense. Here will see a very convoluted construction detail in ICC 1300 that contractors will neve...
ICC 1300 Where Did 22 million bucks go?
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ICC 1300 was a very expensive endeavor. I traced its costly evolution from the $6,000,000 CUREE Cal-Tech Wood Frame Project to the last FEMA grant that created FEMA P-1100. This amount ballooned to over $22,000,000 as FEMA kept funding research in residential seismic retrofitting. This research produced very little, if anything, that a contractor can use. It is a terrible example of government ...
A Comparison of The Tables In ICC 1300 and Standard Plan A
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Both ICC 1300 and Standard Plan A have tables that a contractor must use when designing a retrofit. The ICC 1300 tables have one serious flaw besides being difficult for the average person to understand. They specify hardware, but do not tell you exactly which hardware it is. Instead, one must use their imagination and hope one guesses correctly. For example, it refers to the Simpson L90 as a "...
ICC 1300 Contains Terrible Engineering
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Every cost-effective retrofit tries to make sure the capacity of each component is equal to the capacity of the other components. For example, if a cripple wall retrofit must resist 10,000 lbs. of force one would want the bolts, framing anchors, and plywood to each resist 10,000 lbs. of force. If one of them, say the bolts, resists 20,000 lbs. of force we have 10,000 lbs. of unnecessary bolt. H...
ICC 1300 And The Simpson FRFP
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The tables in ICC 1300 contain a bolting hardware called "Connector Type B" . The real world name for this hardware is the Simpson FRFP. This video explores its use and concludes it is an inferior hard and should not be part of ICC 1300
ICC 1300 Has Hardware That Does Not Exist
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ICC 1300 uses a series of tables that contain hardware one must use when applying ICC 1300. These tables don't tell you brand or item number of the hardware but rather draw a rudimentary picture of it and hope the contractor guesses correctly. The tables include bolting hardware that bolts the mudsill to the foundation and framing anchor hardware that connects the floor framing to the cripple w...
How to read your no cripple wall proposal 9-22-21
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How to read your no cripple wall proposal 9-22-21
How to read your cripple wall proposal Howard
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How to read your cripple wall proposal Howard
How to read your no cripple wall proposal YellowArrow
มุมมอง 174ปีที่แล้ว
How to read your no cripple wall proposal YellowArrow
ICC 1300 Will Not Protect Your Additions
มุมมอง 222ปีที่แล้ว
ICC 1300 Will Not Protect Your Additions
I understand that the threaded rod should extend 12 inches into the foundation. Even with a rebar cutting bit, my contractor was only able to get 6” down. He epoxied them in. Short of removing them and starting over, is there anything else that can be done? Thank you!
I think you should be OK anyway. I did a lot of research on this . I believe you get full capacity at 6" penetration but as a precaution deeper is better. You can also put the holddown on the other side of the studs.
@@infocook4854 thank you! This news just made my day a whole lot better.
Simple question, does shearwall start at the bottom on top of the concrete slab or overlap on the side of it.
I don't quite know what you mean. The plywood is nailed to the bottom and the bottom of the wood framing.
@@infocook4854 plywood can’t sit on slab because it potentially could sit in water. Bottom plate to edge of slab so shear panel overlaps stem wall or slab. Thanks I found what I needed
-_-
yea, I see so many 35. dollar roto hammers
Thank you. We are planing a seismic retrofit of a 1400 sf lake cottage on a steep lot. The foundation is accessible on the down hill side of the house. This leaves 50% of the foundation only accessible from outside the house. Any suggestions?
Check with the USGS and see what seismic zone you are in based on the Modified Mercalli Scale and see if it worth the bother.
A condo unit that my family owned before - well the 1st building collapsed during an earthquake. we were traumatized by that that we decided not to live in a condo ever again.
Where was that?
@@howardcook35 Philippines
I got EBB approved recently. I was only going to install the universal retrofit foundation plates per code and thought that would be sufficient. However, watching several TH-cam videos it looks like code also requires upgrading mud sill bolts on older homes (mine was built in 1965) and drilling vent holes in cripple wall plywood and would like to know if that’s accurate. Thank Donald
The EBB requires that you use either FEMA P-1100 or Standard Plan A to qualify for the grant. You can find a comparison between the two systems on this webpage. bayarearetrofit.com/fema-p-1100-icc-1300-and-standard-plan-a/ Please study this webpage so that you know which system you want to use. This is an important decision and will make a big difference in terms of cost.
How do you handle floor to cripple wall connection when there is neither a rim joist at ends, or any blocking between , the floor joists sitting on top plate - perpendicular to the cripple wall? Add 2x blocking & use L90s? Or hurricane type ties at the joist/plate connection? Both?
Add blocking. First joist bay in line with the top plate and use an LTP4, the next joist push the block against the siding and use an L90 on down the line a few bays beyond the shear wall.
@@bayarearetrofit5814 Got it - thanks info, your thorough videos are stellar btw - much appreciated. Re: add blocking - usually just toe nail (or SDS screws? ) both ends of the block? Seems like proximity to ends of both the joist & block may split the wood ? Hmm a last thought: if working left to right, suppose one could toe nail the LH side then use a longer fastener & end nail the RH side thru the RH joist from each adjacent joist bay ? May gain some strength vs toe both ends etc
You just need to hold it there enough so you can put in the hardware
@@bayarearetrofit5814 Interesting, thanks. Makes sense to me the hardware would transfer lateral forces from joists/blocking, thru L90's block nails, thru L90's , into to top plate, and on down etc. But.... what about vertical forces moving through same system? Couldn't the house above shear walls also want to jump off the top plate? Seems like the toe nailing of floor joist blocking then becomes a relatively weak point of vertical load path: if it's top plate-->L90-->block-->joist-->1st floor/walls ?? Just trying to understand how engineers look at this, sure I am probably missing something!
The house goes up with the foundation and down with the foundation. Vertical thrust is not a consideration in the building code, even with thrust faults such as the Hayward Fault.
You are a fantastic educator. Thank you so much for this video. I learned so much by watching it. Would you please explain what is the "reverse block method"? It was ranked as the second best method in the letter you referenced. Thank you for your time.
Go here bayarearetrofit.com/mudsill-connection-in-cripple-wall-retrofits/
Are you sure transferring all of that energy from a earthquake into the structure and the occupants in that structure is the best answer for serving a earthquake? The reason the houses that slid off their foundations look so intact is because the energy did not transfer from the foundation into the structure. Actually decupeling the foundation to allow the structure slide across the foundation but not fall off of the foundation.
If the connection between the floor and the foundation is strong enough the house, foundation, and earth will all move together. The house above the floor will be able to take the shaking just fine. The houses stay more or less intact regardless of whether or not they slide off the foundation but in one case you have a house to live while in the other you have nowhere to live. bayarearetrofit.com/see-what-cripple-wall-damage-looks-like/
Great video. Thanks.
Most engineers don't know about rotational retrofits. I agree, it is important information. Be sure to subscribe.
Awesome video! I have a house that was built in 1919 in El Granada. I have cripple walls and need to retrofit. This video helped a lot. Thank you! By the way you mention special plywood for the shearwall? What would that be?
Excellent video
Thanks, it was a lot of work.
Great Video, I just qualified for the Earthquake Brace and Bolt program so I'm trying to learn as much as I could in a short amount of time. This video was better than the ones on the EBB website. I do have a question: For a post and pier foundation, with a masonry perimeter (stone & mortar), can you anchor the mud sill to the stone wall? Or will you it be best to create new cripple walls along the interior of the crawl space? Thank you!
Look at the video on old foundations. Install new foundation segments parallel to the stone and build and brace cripple walls of the new foundations
5:47 Guys Can anyone find a video of table shaking earthquake test in this minute of the video?
I reside in Oregon where we are vulnerable to an expected and extremely powerful earthquake due to the Cascadia subduction zone off our coast. Though our building codes may differ. I found this video to be very informative on how to mitigate home damage from seismic activity
what is the size of the shake table ?
Looks pretty big to me
I was wondering- if my house has no cement foundation and is just on rocks on the ground and some post and pier could I just put a foundation in that comes up to the mudsill plate and eliminates the cripple wall? I am in Eugene oregon.
Yes
And I’m in bed, on a second story watching this video in Los Angeles. Sooooothing.
According to Simpson blog, and some documentation there are alternatives to nails, like the SD and SDS screws and depending on the coating can be pressure wood safe. I’m still in my prep phase for some DIY repairs on the cripple studs and adding retro walls. Theese videos are great ice breakers before I start reading my southern Cali fema guide.
I was on the committee that helped write FEMA P-1100. It is a piece of crap. bayarearetrofit.com/fema-p-1100-icc-1300-and-standard-plan-a/
This is awesome but what should you do to maximize safety from earthquakes? I live right near one! I was going to put on those Simpson ties so I won’t waste my money on these. I have beams supporting a 1-1/4” plywood floor so now floor joists. What should I do?
You should have 4 x 6 beams on the entire perimeter. Connect those to the sill with Simpson L90s, add URFP, make sure and engineer it with the info on the website, and call it a day. If you could post a YELP review that says some good things about the website and your experience with me it would be appreciated
@@howardcook35 many thanks Howard! I will do!
All this talks about is what NOT TO DO, how about WHAT TO DO ???
You missed the point. THERE IS NOTHING TO DO.
would have helped more if you showed the CORRECT way to do it and not shighting on others work
I quoted the code. It is up to the reader to decide if I am shitting on other people's work.
Once a shear wall is that narrow it becomes a post and is rated at zero.
Is there a minimum length for the shear wall section? Using your example, if I use 10d@2" OC and a 24" wall will it support a 1740lb seismic load?
The closer you get to 26.5" the weaker the shear wall. After 26.5 if equals zero.
The test showing the stick construction without plywood sheathing was a little biased. There was no lateral bracing on the building, which is what plywood sheathing provides, of course its gonna rock and move. And also, it didnt even look like that sheetrock was fastened to the wall.
And this, ladies and gentlemen, is why American homes only last about a decade.
I wasn’t always clear in the video whether the retrofit added a plywood/osb panel on the inside or outside of the wall. Would welcome that clarity in a reply if you’re able. I came to the conclusion that generally you depicted interior panels, not exterior. In my case I’m residing a house, so I plan to install on the outside if decide to add.
It does not matter.
Thanks for the info--for homes that don't have cripple walls--just a wall on top of a rim joist on top of a sill plate, how does one secure holddowns? Do we drill through the sole plate down to the mudsill and foundation, bypassing the rim joist? Also, what's the prescribed retrofit of securing the wall to the rim joist?
Why are you putting in hold downs. Do a search on "Overturning" on the website.
@@bayarearetrofit5814 I have a house built in the '50s (southern california) and after installing FRFP plates and shear transfer ties, I noted that our exterior walls only have the stucco cladding for shear resistance. Was considering applying plywood on the inside when we strip the drywall (to do insulation and redo electrical) and build shear walls. Hence the question about hold downs.
@@dmtien You do not need holdowns. Look at the video th-cam.com/video/HSDJfLSXoaw/w-d-xo.html Don't waste your money.
@@bayarearetrofit5814 Got it, thanks!
Does the spacing between the blockings matter in the design of the shear wall? Say I have 3 rows of 4' x 8' OSB, does it matter that I have 4' - 4' - 2' going up or 4' - 2' - 4' ? I have a feeling that it does.
Do you mean does it matter if the plywood is vertical or horizontal?
Your a hack trying to justify your past shoddy work. I wouldnt put my dog in a house with no metal post connections. You need to drop your tool bags and sell oranges on the freeway😂
Imagine eating a very delicious hot soup 🍜 at 5:57
Do you know if these can be used on a CMU foundation?
Yes, but only if the CMU is filled with concrete
They're not and I'm trying to see if there's a solution to retrofit to a CMU. thanks@@bayarearetrofit5814
Is fixing the sinking perimeter walls enough or shall we combine attention on both …. I have the case in my crawlspace , the middle piers are kinda sinking not because the soil is softer there but precisely at the bottom of the perimeter foundation walls sinking or tilting cause of water badly diverted around the house foundation walls on which each end of the main girder is sitting. So the support sinking the girder is kind of sliding out of its place n push down on the piers supporting it in the middle .. question is how do you get the perimeter walls issue fixed … I mean once the job of getting the rain water away from the house ? Please give us some guidance there your video threw all my courage down into the deepest spot of the crawl space
The only thing I know is to level the floor. To do it right you need to use a laser. Maybe there is something on TH-cam. I have never done it myself. If you discover anything let me know.
You can use a water level to level the floor. Get 100' of 3/8" or 1/2" vinyl tube and fill it with water. Attach it to two sticks, stakes, or rods. Place one of these against a door frame solidly with the bottom resting on the floor. Do not let it move. Then go around the house and measure the level of water from the floor to the level point. You can then build a map of where your floor is out of level. I will be doing this in my south bay area home built on expansive clay soil in the coming year.
Not helpful at all cause you’re developing above n beyond the wrong done communally done by lots of contractors under guidance of structural engineers but you’re not giving us a clue of how to address failing piers on old houses if not this way … at least if you have it give us an alternative so that we can learn how to address this issue better… thank you
What do you mean by failing?
Extremely helpgul Howard. Thank you.
If a rodent can fit in a hole it will certainly try and if it is big enough they will succeed.
This may be a silly question, but is the air gap created by the plastic piping completely open to the outside? Is that gap an entry point for rodents?
If a mouse will fit you can assume it will be.
Great video 👏
Thanks for the complement. This is one I did not feel like I did a good job with and delighted you found it useful.
@@bayarearetrofit5814 I think you did great, absolutely love the videos, very insightful for a prospective home owner in the bay area 🙏. Have a wonderful weekend :)
Good idea!
Use extra reverse v support of wood to give more support.
You must experiment in another way. We play with rubber ring, make larger rubber ring same as wood, support the rubber ring from earth to top, put it around wood, then it will not spilte easily. The first floor wood will come on rubber as well as on wood. Make wood home as per as design. Rubber ring will support if ever wood try to fall. Second. Use tyres on ground floor in a zic Zack position use three layers, fill the earth in each layers, tyres will not allow jerking waves to pass. When ever earth quack come, breaking of earth occur in line. Third. If person in poor, they can use tyres for support around wood instead of ring. Fourth. Use rubber sheet below wood. Fifth. Use triangular coupling to support wood. Rubber ring are not available at present in market so use playing rubber ring . Japan faces, land slide,earthquake and tsunami flooding at the same time. Jay bharat.
th-cam.com/video/XRg-KD82zLY/w-d-xo.htmlsi=z3W_YeNJ48S6M28U
Use thermocole in between ring. Jay bharat.
Just curious what city building code this is?
International Residential Code
Maybe the supports were installed for support purposes only and not for seismic retrofitting. A lot of houses that were built a long time ago may require additional support over time. Personally I feel the photos were used out of context to make the video, since the drawings or plans do not mention for seismic activity but they also do not mention for structural support. I would think you need some type of shock absorbers or the house to be on rollers to handle serious seismic activity. Posts or no post are not going to save the house from an earthquake. The perimeter of the house would be more important than the middle when it comes to seismic activity.
Please go to bayarearetrofit.com and search for "post to beam" and read the code requirement.
I am very please I could help you. Please subscribe.
It is not old growth redwood. You probably have plywood siding which means you don't need to do anything.
My house was built in 1986. Are the studs in that house considered old growth lumber? Wondering if I need to use 3” spacing for my edge nails on my shear wall.
No, they are not old growth.
Thank you. This is great information for anyone doing a retrofit.
You are welcome. Be sure to subscribe.
Thank you for this information. I have a soft story and split level house in Pismo Beach.