Thursday, January 28, 2010

Restoring Metal Carport Posts

I recently was tasked with replacing two metal carport posts and thought I'd share the experience. While at first this might seem a bit daunting, I think you'll find as you read that it's not as bad as it sounds. Most of the homes in our Northcrest neighborhood have metal posts supporting the 4" x 8" douglas fir support beams that are exposed in the carport and the front patio (if the home has one). This was a very common building practice by P&H Home Builders and is the norm for all the tri-level modern homes in this neighborhood, and those homes built by P&H in Northwoods and other local communities. Howard Hardrath's brother, Buddy, continued with this practice in his version of the P&H Split in Lilburn, Stone Mountain and other areas. It was also used by very many other modern builders in the area, although the pipe diameter may vary a bit.

Let's talk a bit about the construction. These posts are mostly made of 2 1/2" diameter steel pipe welded to a 1/4" thick metal plate with dimensions of about 3" x 6", offset (meaning the pipe is welded to one end of a rectangle). I've found the plate to vary a bit in length, with a minimum of about 5" and getting up to about 5 1/2" at a maximum - the plate always has four holes drilled at the corners where nails were pounded into the beam above for stability. The pipe used provided almost 1/2" of additional diameter provided a total diameter of around 3" (metal pipe is measured by the inside diameter so in order to get 3" on the outside, you buy 2 1/2" pipe, which has a wall thickness of slightly less than 1/4" providing the total diameter). What I find interesting is that almost all of the original posts in the neighborhood only have a plate and are attached at the top - the bottom is the open pipe, usually sitting flat on the concrete pad or brick wall below. I'm not sure if you can get away with this method in modern construction - seems non-code to me. I think this method was used for a practical reason, rather than as a cost-savings one - as the home expands and contracts with weather, there's some movement in the wood - by "floating" the bottom post it's possible to allow for this movement - however this is conjecture on my part. Some of the posts I've seen also have a bottom plate, but strangely they aren't attached either (no nails, lags, etc) so that's not really a clue.

In any case, as with any metal and especially metal that touches concrete, over time and with repeated exposure to weather produced rain water, the bottoms frequently "rot out" - usually it's the posts closest to one end of the building's side or front. With this home it was the two to the outside of the carport, which would have the most access to rain. Normally a little pitting or rust can just be treated - but these posts each had quite a bit of rotting - one was actually hanging from the beam above and both could easily be moved around by kicking around the bottom. (as an aside, if you want to just treat the posts a bit of sanding or grinding of any rust, body filler if there's only some slight pitting, and a bit of good metal primer and paint will go a long way to preserving what's there).

My first task was to determine the width - I initially did this with a good tri-square ruler to determine the general diameter - I later confirmed using an outside-caliper - these posts were just slightly under 3." The next task was to source the goods - there are many good steel fabricators around the area - I got a list of three that were north of here from a friend who used to build homes in Forsyth and Cherokee County. I decided to go with a local shop near Tucker, Dekalb Steel.

You'll need to determine the actual length of the post (make sure you include the plate thickness) by measuring the actual distance from the beam to the floor (concrete or brick) - this can be off by a bit if you think the beam has sagged with the deterioration of the post - just make sure you go over-sized and not under-sized! It's also good to provide a small sketch of the construction for the plate - I did this by going into SketchUp and producing a nice 3-D rendering, and then making a jpg image to fax to Dekalb Steel. By doing this and showing the location of the drill holes, you'll get something closer to what you're asking for - welders produce good results when giving good images and instructions.

It can take anywhere for a couple of days to about a week to turn around the fabrication. If you have access to a good metal shop you could do the task yourself - just make sure you can get a good 90 degree cut on the ends so they're "square" - this typically takes a metal bandsaw. Drill the end plate before welding so you can use a drill-press. Unless you specify otherwise, the post will come "raw" - complete with surface rust and any marks used by the handlers - you can have them paint it but it'll cost more and they usually just spray some paint on it, meaning that there's not much effort involved in doing the prep before painting so you may get mixed results (sometimes the rust and/or clay or wax scrawl on the metal bleeds through - other times the paint may flake off as there may be some oily or waxy residue on the metal). I chose to get the post bare and do the prep myself. The prep involved a light sanding followed by two coats of metal primer. It was about 16 degrees outside when I started the install so I spent a day doing the sanding and priming the posts on saw-horses, to give the primer a chance to set up. This was done in the sun so that helped harden up the paint. Usually it's too cold to do this type of work but I've found primer to be an exception to the "too cold" rule - later I'll relate how I got the black paint to dry in this type of cold.

The next step is to remove the old posts and replace with the primered new. To do so there are various methods, but as I had an extra screw-type jack-post I decided to use it. I nailed a short tubafor to the bean near the first post - with a bit of the nail-heads left proud of the surface for easy later removal. Next the post was adjusted so there was plenty of threading left to lift the head of the post (the head is a plate that can be screwed to the tubafor to help keep it from slipping off) - there's a flat threaded collar that can wrenched on, which drives the threaded part of the post up or down, lifting whatever weight is above it. I wrenched up until the old post easily cleared the concrete below - about a half inch. I then measured, cut and placed a forbafor post next to the jack - this was a little added insurance as I don't completely trust the post - probably not necessary but I wanted a bit extra for piece of mind.

Prying the old post off was relatively easy, as was attaching the new post. You'll want to use along level to make sure the post is plumb, holding it in place as you turn the jack screw the opposite direction to bring the beam/roof down. Before taking everything apart, check for plumb again and make any adjustments if you need to. I then repeated for the second post (this one involved the removal and later reattachment of a gutter).

The final steps were to float some concrete along the bottom (there was a depression in the existing concrete where the old posts had "drilled" into the substrate below) and paint the post. I waited until it was a bit warmer to do both of these, as concrete does not set up well in freezing temperatures. I used an oil-based enamel Rustoleum product in gloss black - being the closest color to the existing posts. Because of the cold I added a cap-full of Japan dryer to the paint in a paper cup. Japan dryer is a mix of chemicals (mostly naptha) that accelerates the evaporation of the paint's solvents - in this case the paint was dry to the touch in about an hour and completely hard in a day or two. The hazard of painting oil paints in cold weather is that they just wont harden - there isn't enough temperature for the solvents to evaporate so they remain tacky. Using the dryer is an old painter's trick - just make sure you mix enough to do the whole project and throw out any remaining in the mixing cup instead of pouring it back into the can. A little clean up and I was done.

-- John

Friday, January 1, 2010

Installing Whole House Surge Suppression

I recently installed a whole house surge suppressor in my electrical panel and thought I would relate the experience. In all it wasn't a difficult install, however it involved some planning, especially to determine how I would make room in an already crowded panel. As with anything that is involved with electricity this is one install where I'd recommend a certified electrician if you're not confident of doing the work yourself.

Why Surge Suppression?
Surge suppressors, also called surge protectors, stop voltage spikes from harming your electronic appliances in the home. One type connects to the main electric panel off a circuit breaker or directly between the meter and panel, while the more common type are point-of-use surge protectors for electronics such as computers, telephones, printers, etc. You often see the latter integrated into office-style strip outlets or better yet, back up battery devices (like those made by APC). We have several of these that our computer systems and TV/Stereo systems plug into - a few years ago a broken electrical pole next to the house sent a spike through the cable system frying the cables and knocking out the suppressor on the TV - since we were out of town when it happened all the computers, modems, etc were off so they weren't affected. The suppressor on the TV/Stereo protected all those components as the cable fed into it, saving us a bit of money in replacement costs (or at least the deductible on an insurance claim). Not to mention the threat of a fire - having suppressors just makes good sense.

Electrical disruptions in power are real and they are becoming more of a threat to electronic equipment regardless of whether or not you live in a new home and constant fluctuations happen all the time in my neighborhood. A voltage surge or spike caused by a blown transformer (which happened just a few days ago on my street), downed power lines (ditto last year), lightning, electric power grid switching, etc. are all examples of what can happen to affect your home's systems and appliances. Additionally, over 50 percent of the power surges your electronic equipment will experience are created within your own home when appliances with large motors (air conditioners, refrigerators, washing machines, compressors, etc.) turn on and off. What's more, most electronic devices manufactured today contains micro-processing chips that are sensitive to voltage spikes - even your light bulbs are affected. If your light bulbs seem to wear out quickly then you're probably already experiencing fluctuations that the whole house suppressor can help smooth-out. You need surge protection and lots of it if you want to protect everything connected to your house grid.

The focus of this post is a whole house surge suppressor (I'm hoping most of you already have the type that connects between your more expensive equipment and the outlet). These devices are designed to stop harmful surges and spikes before they can travel towards the electronic equipment in your home. They are not DIY friendly so my recommendation is for a professional, licensed electrician to install a whole house suppressor. A good electrician can complete the task in less than one half hour in most cases and the suppressors are affordable as there are several in the $200 range (figure in about an hour of an electrician's time and you'll see it's not out-of-reach). When calling around you may want to note what type of panel you have (it's usually marked on the panel or you may be able to find a manufacturer on a breaker) as it could reduce the costs of the unit - there are some that install directly in the panel where the first couple of breakers sit in the box.

My Electrical Panel
In my case our home has a 150 amp Cutler Hammer panel with corresponding breakers. I mention that as it's unusual in Northcrest to have 150 AMPS and an original panel from 1964 (when the house was built) - most homes on my street built around the same time have 80 amp fuse boxes or have at some point been upgraded to a 100 amp panel. Apparently the original homeowner of my house sprung for the additional costs - this is both a boon (as the larger panel makes changing things more flexible) and a curse (Cutler Hammer breakers are a great deal more expensive than other manufacturers for some reason, so it can be difficult locating what is needed, especially at a reasonable price). I went through all this last year when I started building out a workshop in the basement - first adding a 100 amp sub-panel dedicated to the equipment, and then finding tandem breakers (those are breakers that make two switches available in the same slot as one - allowing me to move circuits down to make room for the larger, two-pole breakers necessary to power the sub-panel). Once again I needed to move things around to make room for the 30 amp two-pole breaker needed to power the surge suppressor. While in the panel I freed up the first two slots for the breaker required for the suppressor, which hangs off the side of the panel. Finding two tandem breakers wasn't difficult - but at $25 each rather expensive. I found a seller on eBay that had four new tandem breakers for $25 shipped - much more reasonable (as a comparison a single comparable SquareD tandem breaker is $7 at Home Depot).

Choosing a Surge Suppression Unit
There are a variety of units available but in general there are a few things you need to look for:
  1. Joule ratings of 1,900 or greater - Suppressors work the way they do through the use of sacrificial metal oxide varistors (MOVs). Small surges that enter your home over time slowly destroy the MOVs. A large surge can cause instantaneous destruction of all of the MOVs in an instant (you want the MOVs to take the load instead of your appliances and components). The MOVs ability to block surges is measured in joules (how electricity is measured, also called a Newton-Meter). Purchase a surge suppressor that has a high joule rating - 1,900 or more if possible.
  2. Clamping voltage is the next thing to consider - This rating tells you when the surge suppressor will react to a surge. High quality suppressors have low clamping voltages - the suppressor should have a clamping voltage of 330 volts or less. The package will have a Underwriters Laboratory (UL) UL-1449 voltage rating - this is the true measure of clamping voltage.
  3. Warning Lights - Because surge suppressors wear out (due to the MOVs being constantly worked), look for a unit that has lights and/or audible alarms that tell you when the MOVs have worn out. Both the whole house and point-of-use surge suppressors are available with this feature.
  4. Replacement Warranties - Look for suppressors that come with connected equipment and total replacement warranties. Numerous manufacturers will send you a free replacement suppressor when and if yours fails - so the initial cost of the unit pays for itself the first time it fails (provided it happens during the warranty period - most warranty for 5 years or so) - some will pay up to $100 towards the electrician's repair bill when your whole house suppressor needs to be replaced. The better units I researched will also cover repairs of appliances and/or devices if the unit fails to stop the surge.
The unit I selected is made by Panamax - the SEP-200. If you'll look at the stats you'll see it complies with the 4 items above - I also have a bit of brand loyalty to Panamax as it was a Panamax suppressor that saved my TV and stereo equipment when power was forced into my cable lines (see above). If you're into HiFi you'll probably already know about Panamax as they've been a top-tier provider for surge suppression - one of the only providers that guarantees against lightning strikes - they also provide up to $10,000 in appliance replacement costs if the unit fails. This unit can be installed inside our outside of the home, attached to the panel (using a 30 amp two-pole breaker) or between the meter and the panel (not an install I'd recommend to a DIYer unless you're a qualified electrician). I chose to wire it into a breaker - something within my level of confidence to do. Since these units eventually wear out, I wanted something that would be easy to replace when the time comes - another consideration

The Install
I tackled the install in three phases (being the anal-retentive that I am, I actually wrote up a short project plan).
  1. Examine the panel and make a plan, including picking up all components and parts
  2. Rework the panel to have room and prepare all components
  3. Install the unit and test.
The first part was one of the more crucial - I took off the panel cover and sub-cover (my panel has an extra cover that protects the breakers) and examined what I had to do to free up the first two slots. This is where I determined I could combine four 15 amp single slot breakers into two 15 amp tandem breakers. I then sourced the breakers from an eBay seller - who incidentally also sold me the 30 amp breaker necessary for the install of the surge suppressing unit - buy buying it all together I additionally saved on tax (not to mention the tandem breakers were half what I would have paid for a single at Home Depot). Turn around time was less than a week. I did all this stuff before tackling Allen's Tankless Water Heater install (see previous posts).

The second part I tackled one evening while there wasn't anything going on that would require power - I like to disable the entire panel by turning off the main switch while in the box. I'm still very careful as there's still power coming into the panel - but this way I'm not inadvertently taking any risks. I moved circuits around and combined into the tandems to leave the first two slots free. This took about 30 minutes or so of careful striping, wiring and the screwing of clamps (in the breakers)

The third part required that I remove a "knockout" from the side of the panel (the panel has cuts in the sides so you can knock out holes for wires to feed through) - I also removed an unused wire that formerly occupied the same space (went to the steam shower heater which I'm removing). I attached the unit directly to the pane using a spin-clamp - the wires were fed in and tied to the 30 amp breaker and ground/neutral bus (in my panel they are the same - in newer panel they may be separate bars). There's plenty of force in the clamp to hold the unit to the side of the panel - in your install you may want to screw the unit to the wall or extend the box slightly using some conduit. I then tested the unit by turning on the power - everything lighted up just fine. I replaced the two panel covers and was done. Total time about another 30 minutes or so.

A couple of days after the install I was at Allen and Susan's house - it had been raining most of the day and there were several people over for Christmas dinner. Suddenly there was an explosion that caused us all to rush to the front window. Subsequent explosions literally lit up the sky - the transformer right in front of his house (he's about 3 doors down from my house) had been hit by a falling limb - luckily the wet ground prevented any of the flaming embers from igniting anything. It took several hours for Georgia Power to restore power to this portion of the neighborhood. All I could think about was how fortunate I was that the Surge Suppressor was already installed at the house - it provided a level of piece-of-mind that I wouldn't otherwise have felt. Returning home later I found everything to be fine - the unit worked flawlessly.

-- John