Thursday, March 8, 2012

Earthquake Retrofitting 101

The following is just my opinion as a homeowner who has had two foundations redone and has earthquake retrofitted 2.5 houses himself. I don't pretend that its 'the TRUTH' and neither should you. I just hope that I can save some other people some hassle/time.

Well, not exactly.. more of an introduction or something.Since we had a little earthquake Monday morning I've been asked about earthquake retrofitting by like 37 people (no not really, but several at least).

First off, if you have a brick foundation you can not retrofit it. Not no way, not no how. If a contractor is telling you that they can do it they are FOS. I'm sorry, but step one in this case is, 'get a new modern foundation'.

Doing It Yourself
First I would definitely recommend the Berkeley Building Education Center's earthquake retrofit class.
It's an entire day and you will learn soooo much about how to correctly do your own earthquake retrofitting. It's a one day seminar and it costs $95 and it's very, very worth it. The class is taught in two sections. The first half is taught by a Structural Engineer, where he teaches you how to calculate how much retro-fitting you need (if your house is not too complicated). The second half is taught by an actual earthquake retrofitting contractor and he shows you what tools you need and how to use them. Soooo worth the money.

If the class is not timed correctly for you Simpson has a homeowner how-to that I also found very helpful. The Simpson guide tells you how to do everything (and explains the background and terms and some of the science) and what tools you are going to need, definitely worth downloading and reading. The only thing it doesn't show are the hold-downs which are absolutely required for this kind of work. I asked a Simpson engineer and she said it was because they didn't consider installing hold-downs to be a DIY thing?

Permits And Plan Set A
Even I have to admit that this is sorta a screwy situation. Apparently they can not 'force' you to earthquake retrofit your home. This makes no sense to me...if you are going to say, redo your foundation why shouldn't the city compel you to do the earthquake retrofitting at the same time?

If you choose to earthquake retrofit your house its called a 'voluntary seismic retrofit or strengthening' You can't do it without a permit legally, yet they can't require you to do it?

There is what's called 'Plan Set A' which is sorta a combo how-to and permit application in one.
Download Plan Set A and print it out and see if your house can use it. I've been told that the reality is that most houses can not follow Plan Set A but maybe you'll get lucky. If your house is more than a 2 family and/or the cripple walls are more than 4', or if it's more than a two story, you can't use it.
The good news is, if you submit a 'plan set A' permit application you will get a break on the permit fees.

Plan on this costing you around $2k in materials, not including the tools you will need.

In closing, I suggest you first read the Simpson hand-out then read plan set A...it'll make more sense. If you can understand both of those documents you should have no trouble doing the work yourself.

Having A Pro Do It
Here's where it can get weirder I think...I've talked to the main local contractors who specialize in only doing retrofit work.... Each one spent a while trying to convince me of how all the 'other' guys out there don't do it right....I suspect that they all are just using plan set A as a guideline and submit the permits under those guidelines so they don't typically need/use an SE.

If your house can not use Plan Set A then you will need to hire an SE to figure out the plan for you....well, I think that this is the case but I'm honestly a bit confused. The city employee I talked to about this said that I could still use the Plan Set A guidelines to draw up a plan and then they would check it out to make sure it's sound. This sounds to me like they city will do the engineering for you for the cost of your permit fees if you make a first stab at it....that just can't be right....can it?

Hire A Structural Engineer/ Do The Work Yourself
Here is the middle option: you can hire an SE to analyze the house and draw up the permit documents and then you can do the work yourself. This is for the case when you can't officially use Plan Set A.

I've talked to a lot of SEs in the area.....if they brag about doing hospitals and bridges on their website...you can't afford them, trust me.

I will recommend two engineers that I have dealt with in the past.

Tony Demascole is the SE who teaches the earthquake retrofit class at the BEC. He is great, been around for a long while and has probably more experience than anybody else in the area coming up with reasonable solutions. All his vast experience and knowledge comes with a price though, he won't be the absolutely cheapest guy for sure, but he won't be the most expensive either, but he will probably be the best.

Nate Williams of Mosswood engineering. I believe he charges $2500 for a standard seismic evaluation that includes him coming out to your house and measuring and drawing up the plans for permit submittal. He has been working with me on the issues here at Chez 3.0 and he has a willingness to 'think outside the box' and the patience to deal with all my goofy questions.

If you talk to either of these engineers tell 'em Chez Neumansky sent ya.

Having Pros Do The Entire Thing
There will be local construction businesses that advertise that they do earthquake retrofitting also....I would shy away from them and focus on firms that only do retrofitting.

There are three local firms that I interviewed and even though I didn't use them I think that they would be pretty good bets. They all come out and take a look and even draw up an estimate - all for free.

First there's Jim Gillett at earthquakeconstruction. He actually teaches the second half of the BEC class. He's been doing this kind of work for a very long time and works with Tony on a regular basis. I think if you hire him you will definitely get a top notch retrofit job. Be warned though, he has a bit of a 'rough' personality.

Secondly there is Earthquake Safety. The owner came out to the house and we had a nice long chat. I got a good vibe from him.

Bay Area RetroFit has a much slicker web site than Jim above and they have a lot of information also.
Had the least amount of contact with these folks so I don't have a strong feeling about them either way.

Having the pros do the entire thing will probably run you from $5-$10, if you don't have a super complicated house and they don't need to bring in a SE.

Hope this was helpful.

1 comment:

Leif Jackson said...

Chez,

Good thoughts, thanks for sharing them. As a contractor who specializes in residential retrofitting (in Seattle), I especially agree with a couple of your comments:

1. If you hire a contractor, hire a specialist. They will have encountered every possible condition and will know how to properly deal with whatever they find. They will be familiar with the permit process and have a good network of structural engineers, suppliers, etc.

2. If you do it yourself, follow the standard plan exactly or hire a structural engineer. Do NOT rely on intuition to "self-engineer" the project. What seems like it should work, often doesn't.

Best,

Leif Jackson
www.soundseismic.com