Bay Area Retrofit

Transcription

1 Bay Area Retrofit Workers Comp. #2246 Contractors Lic. # Liability Ins GL Bond # D Submitted to: N A C P Dear Thanks for the opportunity to submit a proposal for your property. This proposal is best understood when used interactively with our website, BayAreaRetrofit.com. Throughout this proposal you will be prompted to watch videos and read information from our website. We have found this information to be very helpful to our clients in explaining what we do and why. To find the appropriate content use the Search Box found in the upper right corner of any website page. If the proposal says Type Mudsill Plates in the Search Box please do so and click the arrow. This will take you to relevant information about your retrofit. Type in the Search Box Then Press this Arrow. To start, I suggest you watch Video 7 on soft story retrofits: Type Video 7 in the Search Box to watch this video. This video page has two videos. Watch the one on the right. Many people find the narrative text and illustrations even more informative. The narrative and video together will explain most of what you need to know. BFPSH-Tear Our-Lags-No CB Page 1 of 15

2 Please take note of the following: Your building has a soft story. A soft-story is a weakness caused when a lower story such as a garage is substantially weaker, more flexible, and more subject to collapse than the stories above. The best way to protect against this weakness is to attach the floor above the garage door opening to a rigid steel column called a moment column in such a way that it does not obstruct parking. A retrofit engineer will need to design your retrofit to make sure it meets the requirements of the City for soft story retrofits. According to the Chronicle, 80 percent of San Francisco s weakest wood-frame buildings are expected to collapse, so it is conceivable your building will be targeted in the future. If you neglect to meet the City s current standard you may need to retrofit it all over again at a future date. Type Chronicle in the Search Box and read about the City s concerns with soft story buildings. This work is noisy and we will need to cut into the concrete garage floor and it creates a lot of dust. We have plastic sheeting that we will use to cover your personal property, although if you can position it so this is easy to do we would greatly appreciate it. We will clean up at the end of each day and make sure you will still be able to use the parking after work hours. There is a possibility we may need to disturb lead-based paint. We have been trained by the Environmental Protection Agency to do this in a safe manner. Once we start we will work every day until we are done unless delays are caused by the San Francisco Building Department. The old shelving should be replaced and will be difficult to re-install. This is not part of this proposal. If you find some shelving you would like installed, we would be happy to do this for you so long as the standard shelving and easy to install. This proposal is based on our experiences with structural engineer Thor Matteson s designs and is a fixed price for construction. If you choose to use another engineer we will first need to see his drawings before we can give you a fixed price. If you wish to proceed with the work, first please fill out the Terms and Signature page, then, write in the dollar amount of the contract, and finally, sign and date it. You can then mail, fax, or scan and it to us. Howard Cook BFPSH-Tear Our-Lags-No CB Page 2 of 15

3 Professional Affiliations Course Instructor: Principles and Practice of Earthquake Retrofitting for the Association of Bay Area Governments Lecturer: Retrofit Principles and Practice for the Home Inspection Industry. Sponsored by the Golden Gate Chapter of the American Society of Home Inspectors Keynote speaker The Preservation of Historical Wood-Framed Buildings Sponsored by The City of Victoria Heritage Foundation in British Columbia. Residential Earthquake Damage Inspector, FEMA Mayoral Appointee to the Berkeley Disaster Commission Guest Lecturer: Retrofit Principles and Practice for the Canadian Home Inspection Industry. Sponsored by the Canadian Association of Home and Property Inspectors Member Associations: Earthquake Engineering Research Institute Structural Engineering Association of Northern CA City of Oakland Apartment Building Retrofit Committee Publications: Contributor: Wood-Framed Shear Wall Construction: An Illustrated Guide. Matteson, Thor, Structural Engineer. Illinois: The International Code Council, Co-Author with Wendy, Allen, Engineer for Simpson Strong Tie, Retrofit Mudsill Anchorage Systems, 2007 Seismic Retrofit for Cripple Walls, The Journal of Light Construction. April, 2006 Co-Author and currently updating Bay Area s Retrofit Guidelines: Standard Plan A, Residential Seismic Strengthening Plan, The International Code Council, Homeowner s Guide to Seismic Retrofitting Many other publications available in the PDF Library at Bayarearetrofit.com Featured Contractor in PBS Documentaries and New York Times: The Coming Bay Area Earthquake,PBS/News Hour Seismic Retrofits Offer Shaky Assurance New York Times, Dec. 23, 2011 The Hayward Fault. Predictable Peril. KQED, Channel 9. BFPSH-Tear Our-Lags-No CB Page 3 of 15

4 Bay Area Retrofit Workers Comp. #2246 Contractors Lic. # Liability Ins GL Bond # Engineering for steel column. The structural engineer we recommend for this is Thor Matteson. Mr. Mattesson specializes in residential seismic retrofits and wrote a 180 page book on shear walls published by the prestigious International Code Council. For his work on earthquake engineering he was given an award for Excellence in Structural Engineerinig by the Structural Engineers of California. His book can be seen at This proposal is based on what we know of his typical designs If you choose to accept this proposal, the engineering portion of this retrofit must be negotiated separately with him. This is done to avoid any conflict of interest. Based on previous designs for buildings like yours, I would provide for an allowance of from $4,000 to $5000. He is so experienced; he can probably tell approximately how much the engineering will be just by looking at your building on Google Maps. Mr. Matteson s phone number is Installation of Steel Column and Foundation Work Excavation work: We will need to dig out a wide, deep trench parallel to the garage door opening, install rebar, and fill the trench with concrete. We will then remove the soil and haul off site. Install Reinforcing Steel Reinforcing steel will need to be installed in trench and attached to the steel column. Fabricate, Paint, and Position Steel Column Connect steel column to reinforcing steel in and place in upright position so as not to obstruct parking. Paint column color of your choice. BFPSH-Tear Our-Lags-No CB Page 4 of 15

5 Attach floor to Column It will be necessary to install a drag strut probably made of steel to attach the steel column to the floor. This make sure movement of the floor above the garage is resisted by the steel column. Fill Trench with Concrete Fill the trench with concrete and trowel concrete smooth with garage floor so that a car can still drive over it. Additional Clarification Imagine what would have happened if one, two, or three stories of living space had been built over this garage. This is why living areas above a garage are so dangerous. BFPSH-Tear Our-Lags-No CB Page 5 of 15

6 This catastrophic damage was caused by tipping over of narrow walls on either side of the garage door opening. This soft story triplex collapsed in the 1989 Loma Prieta Earthquake centered 60 miles away.. BFPSH-Tear Our-Lags-No CB Page 6 of 15

7 The moment column below would have saved this house in Santa Cruz damaged in the 1989 earthquake.. The red arrow represents movement of the floor above the garage pushing and pulling on the steel column. BFPSH-Tear Our-Lags-No CB Page 7 of 15

8 The following governs the shear wall portion of your retrofit. Please do your best to remove personal property from the work areas. We only need a little over 4 feet of clearance in front of the new shear wall locations to give us enough room to do our work. Invariably we find something that needs to be addressed that was missed in the first inspection. This includes things like rotten framing that needs to be replaced, cripple walls that have sewer pipes running through them, windows that need special framing, etc. Your retrofit is only as strong as the weakest link and we take great pride in our work. If anything extra like this needs to be done, we will do it as a matter of course at no extra charge. We have put together a webpage and video that contains a general overview of the material you will find in the shear wall portion of your retrofit. If you watch it now, understanding this proposal will be much easier. Please type Retrofit Principles in the Search Box. The Rationale Behind your Design: We have done our very best to meet the design recommendations of the 2013 California Building Code. The Building Department It is important for you to know the role of the building department in the retrofit process. Please type Permits in the Search Box. Foundation Under Porch Please type Porch in the Search Box. FINDING: At the rear the house foundation follows the porch. The foundation is located under the front of the porch rather than the front of the main house which is the floor we want to restrain from movement. Please type Porch in the Search Box. RECOMMENDATION: Install a segment of new foundation under the front of the floor and use it to anchor a new shear wall. New Foundation FINDING: The rear of the house does not have sufficient linear footage of useable foundation to build a shear wall and secure the floor. RECOMMENDATION: Install a new segment of foundation per the 2013 California Building Code for a 2 story house.. Cripple Wall Framing: FINDING: This new shear wall will need new cripple wall framing before a shear wall can be built. BFPSH-Tear Our-Lags-No CB Page 8 of 15

9 RECOMMENDATION: Frame a new wall on top of this foundation using the 2013 International Building Code for high capacity shear walls. Shear Transfer Diaphragm-Connection of Floor to Shear Wall Type Diaphragm in the Search Box. FINDING: The new shear wall needs to be connected to the floor above it with a Shear Transfer Diaphragm. A Shear Transfer Diaphragm is a specially made wood connector that allows a large segment of floor framing to be attached to the new shear wall. RECOMMENDATION: Install a shear transfer diaphragm of sufficient length and size. Install Bolts: Type Foundation Bolts in the search box. FINDING: Carefully selected segments of your cripple walls need to be converted into shear walls. Bolts are an integral part of a shear wall.. All bolts to have International Code Council approvals. RECOMMENDATION: Bolt the mudsill to the foundation at shear wall locations. Install Mudsill Plates: Type Mudsill Plates in the Search Box. FINDING: Mudsills tend to split if the mudsill-to-bolt connection is not strengthened with Mudsill Plates. In addition, tests have shown mudsill plates increase the strength of a bolt by 59%. RECOMMENDATION: Install Mudsill Plates on all new bolts. Install Plywood: Type Plywood in the search box. This webpage explains what scientists have discovered about making the strongest shear walls possible. RECOMMENDATION: Install plywood manufactured and tested specifically for shear walls in such a way that the plywood nailing meets the American Plywood Association guidelines for high capacity shear walls. Use the Flush Cut Method: Type Flush Cut in the Search Box Cut the mudsill flush with the rest of the 2 by 4 wall framing and nail the plywood to it. This configuration has undergone thousands of tests while the Nailed Blocking method used by most contractors and engineers has not. Install Shear Transfer Ties on Cripple Walls: See minute 3:45 of Video 5 FINDING: In order to complete the cripple-wall-to-shear-wall conversion process, the shear walls need to be connected to the floor with steel. BFPSH-Tear Our-Lags-No CB Page 9 of 15

10 RECOMMENDATION: Install laboratory tested shear transfer ties. Install Hold Downs (To Resist Overturning Forces): Type Overturning in the Search Bar. FINDING: Some, if not all, of the shear walls need hold-downs to resist overturning (tipping over) Lateral forces pushing against the top of a shear can cause it to tip over. RECOMMENDATION: Install hold-downs on shear walls to resist overturning. Connect Breaks in Upper Top Plate Type Top Plate in the Search Bar. FINDING: The horizontal 2 by 4 s at the top of the cripple walls, (known as top plates) are not joined together. They will tend to separate wherever they are not connected together. RECOMMENDATION: The top plates should be connected together with either nails or steel. Proposal Review Type Retrofit Review in the Search Bar. This page contains a good review of most everything found in your proposal BFPSH-Tear Our-Lags-No CB Page 10 of 15

11 Documentation and the Building Department For our records and quality control we take progress pictures during the installation and if requested will provide you with the photos on a DVD. These photos are provided as a courtesy and full payment is still due upon completion of job. Draw plans and submit to building department for review. Let us know if you desire a permit. The pros and cons of procuring a permit are discussed on our home page under the Permits tab. and I highly recommend you read it. Oftentimes building inspectors have inspections to do a day and can t devote more than a few minutes to looking at your retrofit. This is not enough time to provide more than a cursory look. We have found the best inspections are done by homeowner themselves. We encourage you to grab some old clothes and ask one of our highly trained technicians to show you what they are doing and why. We charge $ for the time it takes to draw plans for a voluntary retrofit, submit the plans for review, and meet with the building inspector during the course of the job. In addition, City permits usually cost between $400 and $1,000. If you desire a permit, please add $ to the price below. Total Contract Price: $00, Plus price of permit paid to city Job Summary: 00 Bolts 00 Mudsill Plates 00 Linear Feet Plywood 00 Linear Feet Flush Cutting 00 Shear Transfer Ties 0 Hold Downs 01 Top Plate Splice BFPSH-Tear Our-Lags-No CB Page 11 of 15

12 Smoke and Carbon Monoxide Detectors ***As of July 1, 2011 California State law REQUIRES both smoke detectors and carbon monoxide detectors installed in your home. Please indicate on the terms and signatures page if you have one smoke detector inside each bedroom, in the hallway outside the bedrooms, on each additional floor in a common area, and in the basement. You will also need a carbon monoxide detector installed outside each sleeping area in the immediate vicinity of the bedrooms, on each additional story, and in the basement. If they are missing, please install them or the Building Department will not give final approval of your retrofit. If you need additional detectors we can install them for $75 each. Please indicate how many you want us to install on the Terms and Signatures Page. If fire safety is a concern of yours, one common approach is to install a gas shut off valve. We have found the company Quake Prepare at QuakePrepare.com to be a reliable and cost-effective company. BFPSH-Tear Our-Lags-No CB Page 12 of 15

13 Terms and Signature-Requesting Permit * Owner understands that seismic strengthening does not guarantee the structural performance of this building. Earth movement from earthquakes and a building s ability to withstand that movement are beyond the control of contractor. Contractor hereby disclaims any express or implied warranties that the seismically strengthened building will be able to withstand an earthquake without damage to its structure or contents. Initial Here * Contractor not responsible for incidental damage that may occur in adjacent to work such as pipes that are severely rusted and break while being moved out of the way, etc. If it is a minor repair, we will repair it as a matter of course. It is extremely uncommon for this sort of thing to happen but we want it clear that we cannot be responsible for the rest of the house. Initial Here Proposal: Bay Area Retrofit hereby proposes to do the work indicated above at the prices shown. Price includes all labor and materials. Payment: Full payment is due upon completion of work. Payable by: cash or check. Acceptance: I have read and understand the information above, initialed where listed, and hereby accept this proposal for the amount of $. I verify I wish to obtain a permit. The specifications, prices, and conditions outlined in this proposal are satisfactory. I authorize Bay Area Retrofit to complete this contract and understand I will be paying for the Building Permit and a $ free for handling the permit application and any inspections that require our presence. Signature Date Print Name BFPSH-Tear Our-Lags-No CB Page 13 of 15

14 Terms and Signature-Not Requesting Permit * Owner understands that seismic strengthening does not guarantee the structural performance of this building. Earth movement from earthquakes and a building s ability to withstand that movement are beyond the control of contractor. Contractor hereby disclaims any express or implied warranties that the seismically strengthened building will be able to withstand an earthquake without damage to its structure or contents. Initial Here. * Contractor not responsible for incidental damage that may occur in adjacent to work such as pipes that are severely rusted and break while being moved out of the way, etc. If it is a minor repair, we will repair it as a matter of course. It is extremely uncommon for this sort of thing to happen, but we want it clear that we cannot be responsible for the rest of the house. Initial Here. Proposal: Bay Area Retrofit hereby proposes to do the work indicated above at the prices shown. Price includes all labor and materials. Payment: Full payment is due upon completion of work. Payable by: cash or check. Acceptance: I have read and understand the information above, initialed where listed, and hereby accept this proposal for the amount of $. I verify I do not wish to obtain a permit. The specifications, prices, and conditions outlined in this proposal are satisfactory. Signature Date Print Name BFPSH-Tear Our-Lags-No CB Page 14 of 15

15 References Earthquake retrofitting is the art of applying structural engineering principles to a building so that it can withstand the violent shaking caused by earthquakes. The people below know us well and can confirm our understanding of these engineering principles and our ability to apply them. Our primary consulting structural engineer is Thor Matteson. Mr. Mattesson specializes in residential seismic retrofitting and wrote a 180 page book on shear walls published by the prestigious International Code Council. For his work he was given an award for Excellence in Structural Engineerinig by the Structural Engineers of California. He too can attest to our competence. His book can be seen at Thor Matteson-Structural Engineer Author of Wood-Framed Shear Wall Construction, An Illustrated Guide Published by the International Code Council Thor@shearwalls.com Larry Guillot-Owner of QuakePrepare Earthquake Preparedness Consultant Quakeprepare.com larry@quakeprepare.com John Fryer President-Bay Area Chapter American Society of Home Inspectors johnfryer@gmail.com Ron Loar - Berkeley based engineer with 50 years experience ronloar@comcast.net Phone: BFPSH-Tear Our-Lags-No CB Page 15 of 15