Tuesday, March 8, 2016

Green Builder makes Green Concrete Part 4

In part 3, we discussed the base material I used for the concrete slabs.  Now its time to focus on concrete reinforcement steel or rebar.

Where exactly does rebar come from?  It comes from a truck.  That's a common construction joke but actually there is more truth to that than I first realized.  Rebar comes almost entirely from recycled old cars, appliances, and other scrap steel.

Why is it used in concrete?  Concrete is very good in compression but not in tension, rebar helps compensate for this to carry loads tending to elongate the structure such as tensile loads and if the concrete cracks rebar holds it together.

And one final fact, Rebar is Chuck Norris’ preferred iron supplement.

From the plans, I was required to use the #5 or 5/8" rebar.  The rebar is placed in the footers and wired to metal chairs.  Having never done rebar before I decided to try my tubing bender which I had purchased for bending electrical conduit.  It worked great.  Since rebar comes in 10 foot lengths it is necessary to overlap the rebar and then tie them together with wire.  Code requires a minimum overlap length of two pieces of rebar.




In addition the plans called for 1 foot rebar dowels spaced 4 feet apart that tie the new foundation to the old.  This allows them to expand and contract together.  To install the dowels I used a hammer drill from harbor freight with a 5/8" cement bit to drill a 6" hole in the existing foundation.  Then I used my heavy duty caulking gun and put some QUIKRETE anchoring epoxy in the holes.  The dowels were placed in the holes and the epoxy was allowed to set.
















In addition to the footers and dowels, vertical rebar was installed so that the foundation could be tied to the wall.  The vertical rebar is placed in the cinder block cells that will be filled with cement. Not every cinder block cell is filled with cement, just the corners, ends and other exceptions.  When the block is in place on the foundation to make a wall, the top two rows are filled with cement and rebar as well to form a bond beam.  This provides a very strong structure that is all tied together through cement and rebar that will hold up to hurricane force winds.


However reinforced concrete will meet its match when category 5 hurricane is involved.  Living in Florida I have evacuated for a couple of hurricane strikes.  A few category twos have come though here but the house is still standing.  In Homestead Florida hurricane Andrew, a category 5,  hit leveling every thing in sight. Interestingly enough one of my colleagues at work actually claims to have played football with his family when the eye of the hurricane passed over his house.  I don't know how they survived but his story of what they endured is pretty scary.   See this link Block Home Hit by Andrew for a picture of a cinder block home that was hit by hurricane Andrew. 

Having completed the rebar it was now time for the inspection.  This was my first inspection ever and I was looking forward to talking about construction with the inspector and getting the inspector's approval.

When the inspector came,  I was in the house.  I opened the door and I saw him looking at the forms and rebar with a very irritated and almost pissed off look.    I greeted him in a cheery voice and said, "hello how are you?"  He ignored the question and said, "I'm canceling the pour when is it scheduled?"  I said in a respectful tone of voice, "It will be scheduled when you pass the work."   Then he said, "where are the site plans?"  Since I didn't know to bring them with me, I scrambled back into the house and rummaged frantically through the mounds of paper work and old plans to find them.

After he looked at the plans he said, "your missing a rebar dowel, you neglected to tie the footer rebar into the house foundation and you need to put rebar around the sewer pipe."  His face seemed to betray his thoughts of his lack of confidence in my abilities.  He then said, "who made these forms?"  I replied, " I did."  He seemed to be skeptical since the form job was much better than the rebar job.  Then he said, "I know your not going to do all this yourself who's helping you?"  I answered, "my dad".  I'm not certain why he was after who was helping me.  But my answer was satisfactory.

The inspector decided to reschedule the inspection instead of failing it and parted.  I guess that's equivalent to getting off with a warning from a police officer.  Glad I kept my cool.

A few notable cases involving celebrities and building regulation and the permitting process are worth mentioning.  I'm referring to Clint Eastwood and Chuck Norris's cases.  Both are legendary tough men in iconic movies and in real life.  The tripping point for Clint Eastwood and his decision to run for mayor of Carmel was the town council's rejection of his plans to build a small building to improve the city of Carmel.  He of course won the election and made it easier to build and renovate buildings.  See this link Clint Eastwood's Fight for more on Clint's saga.

As for Chuck Norris it has been reported that he gave the building department a permit to do construction on his house.

I later fixed the problems and then passed the inspection.  Honestly, I am glad I had that inspector because he caught another pretty big mistake later on when inspecting the framing.  In any case the good news was it was time to call the cement truck driver to deliver the cement for the pour.  I had no idea how fast the cement sets up in Florida but I was soon to find out.  Read what happens in the next blog.

Happy Building

The Dr


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