Simpson AutoCAD plugin

Another note about doing your deck design, and Simpson hardware (which you will pretty much by default in most cases.)

If you do use AutoCAD for your design, don't forget to download the Simpson AutoCAD menu.  It's free, and is really useful for joist plans and footing plans.

Here is the footing detail from my own plans.  I think the detail from the post base and cap really show the strength of the design.

 

The menu is pretty straightforward.  After you download it, it will need to index overnight before you can use it.  Anyway, it makes your designs look pretty professional, and gives reviewers a good visual of what you are trying to accomplish.

San Diego Deck Permits

Well, I'm back from my first trip to the City of San Diego Development Office.  $505 dollars poorer, three hours more frustrated, and with no permit in hand.  A few quick notes on what I learned today:

1. The office keeps very short hours (10-2) on Friday
2. The actually workers are out for lunch from 12-1
3. Residences 50 years old or older require an additional historical review
4. The property line on some older houses may be out of compliance

Pretty tough day.  I've spent long hours focused on actually deck planning, slaving over AutoCAD, learning about deck building techniques... You know what?  After an entire day at the development office, no one has even looked at an actual deck plan. 

I know deck reviews will come (and probably be painful too), but the entire focus today is on our plot of land.  Our WWII box of a house has no historical significance, but they age triggers a review regardless.  It will only cost 1/2 -1 hour of their time ($75-150 of my money) but provided no value, and takes 10 days in the best case.  Painful.

In addition, our property is built up too close to the curb for modern standards.  That triggers a post review of the property.  I'll find out on Monday just how painful that will be, but I'm guessing the pain will equate back to more money.

Galvanic Corrosion... Say What Now?

If you've never heard of Galvanic Corrosion, you aren't alone.  But if you are picking out metal hardware for your deck, it's time to dip your toe into a little science.

I'd never heard of Galvanic Corrosion until I started asking why hardware manufactures always say not to mix different metals for fasteners and hardware.  After all, if you have zinc coated hangers (like I do) and want to use stainless nails (yup, me) that would be great right?  Maybe.  Or maybe not.  Depends on who you ask apparently.

The Escape Hatch

At a very high level, Galvanic Corrosion means different metals can exchange electrical currents, possibly causing one to degrade much faster than it would usually.  That may be enough info for some.  Got it, just use zinc nails with my zinc coated joist hangers... or stainless with stainless.  Good to go.  Jump off now before this gets complicated.

The whole story is way more complicated.

The Standard Line

Here is a quote I've seen repeated in various forms throughout the internet:

Can I combine stainless steel and hot-dip galvanized steel?
No. Stainless steel connectors or fasteners cannot be used in combination with galvanized connectors or fasteners. These two metals are sufficiently dissimilar that zinc will be protecting the entire stainless steel component and, therefore, will corrode at a more rapid rate.

this is from "Corrosion of Metal Connections in Preservative-Treated Wood Structures" on Toolbase.com, a research lab.

And another from DeckMagazine.com

For instance, because stainless steel will degrade galvanized steel, especially in a marine environment, don’t install galvanized joist hangers with stainless steel nails.

in a very good article "Fighting Fastener Corrosion".

So it sounds pretty cut and dry, even if they don't really site any scientific evidence.  Don't mix Zinc coated and Stainless hardware.  Except that isn't what everyone is saying.

The Heretics

So it gets a little more complicated from here.  Here is a quote that essentially contradicts (or at least qualifies) the opinions above.

When zinc-coated screws are used to fasten stainless steel plates, the screws will corrode rapidly. But when stainless screws are used to fasten zinc-coated steel plates, neither the screws nor the steel will corrode particularly fast.

this is from a Metallurgical Engineer in "Understanding Galvanic Corrosion" at Design News.  It's a very interesting article.  It isn't taking a position on whether you should use stainless hardware, just discusses the metallurgy behind Galvanic Corrosion.

Another, even more technical resource, gives a remarkably similar answer

Does galvanic corrosion occur when these metals are in contact?

... when stainless steel (300 series) are in contact with zinc, neither material will suffer additional corrosion, or at the most, only slight corrosion.  The slight corrosion is usually tolerable when in this bimetallic contact.

 This is from a PDF Q&A called Dr. Galv on the American Galvanizers Association.

I'm not even going to try to summarize the science.  I'll just say they make a pretty convincing case that as long as the stainless is smaller than the zinc, the corrosion effects will be minimal.

The Manufacturer

Since I've already selected my joint hangers - Simpson LUS210Z - what does Simpson have to say?  I emailed their customer service.  Here is their response:

Simpson Strong-Tie® recommends fasteners with a coating that meets the specifications of ASTM A153 be used when using ZMAX/HDG galvanized connectors.

We also recommend the use of stainless steel fasteners when using stainless steel connectors.  It is a known fact that the galvanic corrosion can occur when dissimilar metals are in contract in the presence of an electrolyte.  

Simpson Strong-Tie has not performed any research on galvanic corrosion or the extent of corrosion when stainless steel fasteners are in contact with a  ZMAX connector.
Attached is information on galvanic corrosion published by “The Specialty Steel Industry of North America (SSINA)”.

Thank you,

Customer Support Technician
Engineering Department
Simpson Strong-Tie Company Inc.

Here is the chart they referenced from “The Specialty Steel Industry of North America”.

 

The Verdict

Well, I'm going to email some of the sources above, see if I can get any comments.  Personally, if I could ask for one thing, it would be real field research on long-term effects of Galvanic Corrosion.  Particularly in the context of a marine environment.  I doubt I'll get it.   So unless my inspector enforces his opinion on this, I'll be left with conflicting information to make my choice.  

If I had to decide right now, I'd go with stainless nails on my zinc hardware.  I think the risks of corrosion of the zinc hardware don't overwhelm the known effects of ACQ pressure treated lumber and marine air on non-stainless nails.  Is it the right decision?  I guess I'll let you know in about 15 years.

Feel the tension in the... rail

Our house has a fence around the backyard.  It's about 60 years old, and is in rough shape.  It never fails though.  We have a party, and the minute any boy under eight arrives in our yard, he is trying to bounce off the fence.  Fortunately it has never failed us.  I'd like to say the same thing about my deck railing one day.

Poorly built railing injury more people than any other deck issue other than collapse.  So even if it's that last thing you plan on your deck, its worth spending some time focusing on.

Here are a few decisions you'll be facing:

Railing Posts

Post have to attach to your deck somehow.  Your options are:

1. Inside the joist, bolted to the joist 
2. Outside the joist, bolted to the rim

Personally, I am planning outside.  I like the way inside railings looks, but I think they have a couple issues.  They take away useable deck space, and they introduce a lot of cracks for water to get trapped in.  Good hardware can make outside connection plenty strong.

Lag Bolts and Carriage Bolts

I don't think there is any question here.  Carriage bolts, stainless in you can fit it in your budget, with a big fat washer.  Lag bolts can't be tightened over time without stripping out the wood eventually.

There are a lot of sources for carriage bolts, but your probably going to need to really long ones for this.  I'm looking at 1/2" x 7 or 8 inches long.  Take a look at Bolt Depot, and compare prices from there.  They have a good selection, including Stainless Carriage Bolts in 18-8 type stainless.

I've had some luck finding bigger groups (like 25) cheaper on eBay too.

Rail Tension Hardware

I'm adding some rail tension hardware as well as the Simpson DTT2Z-R2 Deck Tension,
over at Amazon, they have a 20 pack as well, which is a pretty good deal at $6 each.

These tie the railing into the joists on your deck.  That adds a couple thousand pounds of lateral resistance.  Not sure there are any major alternatives to this product.

Using the Bosch GLM 100C Laser Measurer

I've been playing with my new Bosch GLM 100C.  It's a really interesting evolution of the laser measuring device.  I thought I'd link together some videos of setting up and using this device with my Android OS Samsung Galaxy Nexus phone.

First step is pairing the GLM 100C with your phone:

Unfortunately, the directions are pretty sparse on the pairing.   Here are the steps I used to get it up and running:

On the Bosch GLM 100C

1. Turn it on
2. Press the Bluetooth button
3. The Bluetooth icon appears on the screen

On the Phone

Get the Bosch GLM Measuring software

1. Download a "QR Code Reader"
2. Scan the QA barcode 
3. Follow the link and download the application 

Pair the Bosch with your Phone

1. Go to your settings
2. Open the Bluetooth settings
3. You should see the Bosch under "unpaired devices"
4. Select the Bosch GLM100C, and it will automatically pair

Using the GLM Application

1. Open the app
2. Select "Remote" from the bottom menu
3. Open the menu in the top right
4. Select "Bluetooth Connection"
5. Select your Bosch GLM100C from the options

Take some Measurements!

1. Black bar above will say "Connecting to Bosch GLM100C"
2. Go back to the "Remote" screen, the remote button should now be red

The applications for deck building are pretty obvious in general.  Another feature I'm pretty excited about is the ability to calculate a triangle.  I'm not sure I'll need it for this deck, but if the deck had any elevation at all, it would make a lot of sense.  Did a quick instruction video on that as well.  Pretty simple, but cool.