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CONSTRUCTION KNOWLEDGE BLOG

February 10, 2010

Useful Facts when Converting Construction Units
Filed under: Phone Apps for Construction — Tags: — nedpelger

I’m finalizing the first four construction phone apps and want to add some helpful facts to the Converting Units for Construction program. While it’s helpful to have all the units available to convert weights, volumes and densities, it’s even more helpful to have a few sample densities listed that keeps the process in perspective. For example, finding that steel weighs 480 pounds per cubic foot (pcf) while aluminum weighs 165 pcf and wood about 35 pcf may help you solve some real problems on the jobsite. I have a list of densities below (do you think more would be helpful? Anything specific you’d suggest?):

Density of Common Units in pounds per cubic foot (pcf):

Aluminum: 165 pcf

Brick: 120 pcf

Concrete: 145 pcf

Copper: 560pcf

Corn: 45 pcf

Crushed Stone: 100 pcf

Fresh Snow: 8 pcf

Glass: 162 pcf

Lead: 710 pcf

Paper 58 pcf

Steel: 480 pcf

Water: 62 pcf

Wood: 25-45 pcf

I’m also considering other useful facts to add into the phone app. For example, the various values of energy and power listed below are occasionally useful. Do you have any other ones you would add?

Energy (work done, think kw-hrs or BTUs)

Gasoline (mid grade) 1 gallon = 125,000 BTUs

#1 Kerosene 1 gallon = 135,000 BTUs

#2 Fuel Oil 1 gallon = 138,000 BTUs

#6 Fuel Oil 1 gallon = 150,000 BTUs

Ethanol 1 gallon = 76,000 BTUs

Propane 1 gallon = 91,600 BTUs

Propane 1 cubic foot = 2,500 BTUs

Natural gas 1 cubic foot = 1,030 BTUs

Wood (air dried) 1 cord = 20,000,000 BTUs (chord = 4’ x 8’ x 4’)

Wood (air dried) 1 pound = 8,000 BTUs

1,000,000 BTUs of Energy =

10 therms or 1,000 cubic feet of Natural Gas

46 pounds or 11 gallons of Propane Gas

8 gallons of Gasoline

7 gallons of No. 2 Fuel Oil (diesel fuel)

293 KW of electricity

125 pounds of air dried wood

71 pounds of coal

Power (capacity, think KW or HP or BTUs/hr)

1 Kilowatt = 3,413 Btu/hour

1 ton of air conditioning = 12,000 Btu/hour

1 person in a room adds about 250 Btu/hour or the equivalent of a 75 watt light bulb

1 HP (motor) = 746 watts (operating energy)

A Formula One racecar is 1000 HP and would use 20 gal/hour of gasoline (if it used gasoline)

A Ford Pinto is 88 HP and uses 2 gal/hour of gasoline

If you can think of any other useful facts that belong in a phone app for converting construction units, please post a comment and let me know.

CONSTRUCTION KNOWLEDGE BLOG

February 9, 2010

Unemployment Drops under 10% but nears 25% in Construction
Filed under: Industry outlook — Tags: — nedpelger

A recovery of sorts seems to be happening in America. With unemployment dipping below 10% for the first time in months and factory orders increasing at a faster than expected rate, we have some reasons for cheer. This surge in factory orders bodes well for an economic turnaround.

Construction, on the other hand, acts as a lagging indicator and the pain we now feel doesn’t seem likely to get better in the short term. ENR noted that the construction industry unemployment rate hit 24.7% in January, the highest since February 1983.

I was standing in an unemployment line for a couple of weeks just about exactly 26 years ago and it was unpleasant. For those of you in that situation, I offer some of the best wisdom about construction industry trends I’ve ever heard:

“When things are good, they aren’t nearly as good as they seem and when things are bad, they aren’t nearly as bad as they seem.”

Finally, keep in mind that everything is relative and depends on your attitude. This Russian proverb sums it up:

“The church is near,
but the road is icy.
The bar is far away,
but I will walk carefully.”

CONSTRUCTION KNOWLEDGE BLOG

February 8, 2010

Building an Igloo
Filed under: Cool Projects — Tags: — nedpelger

My son-in-law, grandson and I built a fine igloo this weekend. Since the plowing of our driveway left a big pile of snow, we decided to tunnel.

Actually, we began by trying to make snow blocks to lay in place to form an igloo. That didn’t work. The snow simply doesn’t pack well enough to be stable.

So we started with this big pile of snow and took our shovels to shape and tamp. We tried to create some increased density in the snow. Then we started to tunnel.

After about 4′ of tunnel, we made the room more expansive. I had some significant concerns about the stability of the snow, but it seemed to be holding up well.The photo below shows my grandson Clay checking out the progress.

We eventually got ourselves into the igloo. The photo shows the dog barking at us from the outside. For some reason, she would only come in for a few seconds, then run right back out. Maybe she was a bit smarter than us?

As we built the igloo, I kept thinking about the relative dangers. Snow only weighs 18 pounds per cubic foot, about 6 times less than soil. So that made me feel a little better. Also, I kept tamping the cut areas, trying to make sure the snow would act as an arch and transfer the gravity loads around the opening. In the end, I’m still not sure if it’s a stupid thing to have built and occupied this thing (photo of the 3 of us in the igloo).

So what do you think? Was it a stupid risk or just some reasonable fun to build the igloo?

CONSTRUCTION KNOWLEDGE BLOG

February 5, 2010

Beware Permanent Problems
Filed under: People Skills — nedpelger

In 2010, I’m starting my prayer time each morning by reading an essay from the Oxford Book of Essays. These short essays give wisdom from a variety of authors through the ages. It’s a nice way to stretch my mind.

I’ll occasionally share some passage that moves me. For example, in 1642 Thomas Fuller wrote “Of Anger” which has the following passage:

“Take heed of doing irrevocable acts in thy passion. As the revealing of secrets, which makes thee a bankrupt for society ever after: neither do such things which done once are done for ever, so that no bemoaning can amend them. Samson’s hair grew again, but not his eyes: time may restore some losses, others are never to be repaired.”

We all create problems for ourselves with some of our decisions. We need to be careful to avoid those problems that could turn permanent. When I was a young PM, we were placing a concrete floor on an office building. I happened to be on the jobsite when high winds started flexing the steel joists in the roof and moving the concrete block walls. I remember running down to the guys finishing the concrete and yelling, “Get out of the building now! I think it’s going to collapse!” I was only 27 years old and I’m not sure why they listened to me, but they did and the walls and steel collapsed about 30 seconds later, right where they were working.

It was a great lesson for me to take the risk of appearing foolish and do what seems to be right. In the case above, it worked great. Of course, I also remember almost being thrown off a bridge by a truck driver I’d just accused of cheating on his hauling runs, only to later realize I’d made a math mistake in calculating the run cycle. Man was that guy mad!

Wisdom in this business involves a mix of trying to do the right thing while considering the long term result of our actions. It’s not easy, but worth the effort. In a nutshell, live the examined life.

CONSTRUCTION KNOWLEDGE BLOG

February 1, 2010

Snot Stalactite
Filed under: Ned Weirdness — nedpelger

I believe in trying to keep my body reasonably fit and strong as I age. To that end, I ride bike with some buddies early Sunday mornings. Yesterday was cold (10 degrees F at Curt’s house) but we don’t let that stop us. After being out about an hour, I got a flat tire. As I began to replace the tube, I looked at Curt and saw this 1 1/4″ mucus-icle hanging from his nose. He had no idea it was there. So of course I needed to capture this disgusting Snot Stalactite on my phone camera and share it with you.

With a friend like me, Curt has no need to worry about his enemies. For those of you interested in justice, though, you’ll be pleased to know that he did thoroughly kick my butt on the ride.

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