Masonry Walls – Re-in-for-cement Rebar reinforcement is manditory

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Tips & Tricks

BENDING FOR PLACEMENT: If you have a $400.00 rebar cutter, bending rebar is a snap, but if you don't you will find this very useful in bending ½ to 5/8" rebar. Get two pieces of 1" galvanized or black steel pipe 2 to 3 feet in length. Slip both pipes together over the rebar down to the point where you want to make a bend - measure if necessary - bring the two pipes together exactly where you want the rebar to bend. Place your foot on one pipe (close to the bending point) and grab the other pipe or rebar and raise to the degree you want bent - usually 90 degrees. Be sure to lift with your legs and not your back. If you have trouble, solicit help - one stands on the rebar while the other lifts. Keeping the two pieces of pipe touching while you bend will give you a nice tight corner, instead of a round sweeping corner that may not fit inside a tight space. CUTTING WITH A HACK SAW: You will find you can cut your sawing time by a third by following this simple technique: Measure and mark your cut (a welders soap stone shows up nicely on rebar) saw 1/3 of the way through the rebar. Place both pieces of pipe (see above) joined together over the cut (cut side down) and bend. The rebar will break right at the saw cut. TYING RE-BAR IN PLACE: I started using duct tape several years ago instead of tie wire to tie my reinforcement racks in place - so far it has passed every inspection. The trick is to start your tape coming off the roll by tearing horizontally ½" wide - as you pull the tape it will continue to tear very easily as it comes off. This will give you a piece of tape ½" wide to tie with. Tear a strip about 8" in length and wrap around your joining sections to hole your rack in place. The only thing inspectors have asked is that I not let the tape cover more than 1" of the rebar where it is spliced.

___Masonry Walls More Than Block & Mortar!___

(Part Three of a Trilogy!) This is the conclusion in a three-part trilogy on masonry walls. In the first letter I covered the approach to planning for a wall that will out last your mortgage. In the second letter I covered how to get around using an engineer in special circumstances. Now it is time to tell you about reinforcement (re-in-for-cement) that is hidden by the surface of the block and buried below the ground in the footing. Rebar is the common reinforcement that concrete needs to help hold it together as it expands and contracts. Typical walls have rebar every 4'. The rod is either 5/8" or 1/2" in diameter and the laps should be 40 times the diameter. The placement of these bars is critical in allowing them to do their job. Rebar is rather soft and can be bent easily by hand. It only serves as re-in-for-cement when it is surrounded by a minimum of 1.5 Inches of concrete. This doesn't allow for much tolerance inside the cavity of a block that is 4"x4" square. It must be centered in the cavity. In the footings as well, the re-bar must be 3" from any dirt for two reasons. 1. To deter rust. 2. To encase it in concrete. In the horizontal joints of the block (bed joints) there should be wall reinforcement-wire inlaid in the mortar joints to help with horizontal sheer pressures (like wind) exerted against the upper wall - every 16" on center. The top of the wall will have two pieces of horizontal re-bars in between the second and last courses which should be grouted solid (called a Bond Beam). The footing will have a minimum of two re-bars running horizontally through out - with a minimum lap of 20 times the diameter (more reinforcement may be needed depending on the width of the footing and size of wall). This is the recipe for a hundred year wall! If you can get your masons to fill each and every head joint (that is the vertical mortar joints) a minimum of ¾ full - solid is better. All of these factors and details are hidden from view. Unless you've been told - or read this newsletter - how would you know? I used to spend a minimum of fifteen minutes with every caller before I will even schedule an appointment. I explain the value and requirements of a masonry wall and assure them they will be met on my job. Here is the clincher: Building this way takes longer, and it costs more in materials. I recently had an old customer stop and ask a mason working in his neighborhood what he would charge for a retaining wall that I told him would cost $4800.00 - this mason was building a planter box a few houses down. His price was $2200.00. My customer - I have worked with him for years - asked me why my price was so high. He had a computer, so I laid out a spreadsheet real fast and broke the job down for him. My materials were $2375.00. He was still perplexed (I knew where to start) I quartered my rebar prices, halved my footing volume and only grouted the wall every four feet at the re-bars (retaining walls are ALWAYS solidly grouted with concrete, remember what I said about making the wall heavier, so goes the footing?) Bingo! We didn't change my labor at all and this new price was $2300.00. Needless to say I built his retaining wall - even in the face of an extremely lower bid. Obviously, I am not trying to sell you on one of my walls, my point is that unless you have a knowledgeable and honorable contractor, you may be buying block and mortar joints… Here is the point to all of this: A wall built in 1981 that cost $2200 would cost $6000 today - apples to apples, same wall. Let's say it was the planter mason I mentioned above that did this wall for you, by now it would have failed and the dirt would have either laid it over in your yard or it would be severely leaning - all who saw it would know there was trouble in Gotham City. So, now twenty years later you need it fixed. That wall (even minus the concrete and grout that should have been there) weighs 52,897 pounds footing and all! That equates to 30 pickup trucks full of garbage! I would charge you $5000 (more than the cost in 1981) just to tear it down, yank the footing and haul it to the dump and then I would want $6200 to install it properly. Go figure, $11,000 has been spent, not to mention the trees, landscape and vegetation that was excavated to get in to demolish and relay and all you have is a wall that should have cost $4000 in 1981. Bottom line: don't necessarily go by the bottom line. The cheapest bid is seldom what it seems. For every technique, volume and placement value, in the wall I described above, that is short cut, years fall off the life of the structure. Check references - old references if possible. Don't hesitate to call the building department and ask them what size footings, re-bar placement etc. that your wall needs. Then put down the remote, log off the Internet and go out and check on those folks that are earning their living in your back yard. You are paying their rent this month, don't be shy: Pry! If they get offended, you will probably really be glad you checked - but hopefully you will never know how glad! For a detailed Multitorial on Retaining and Patio Walls - Holding Back The Earth is a well written and "concrete" instructional on building masonry walls. Well, until next time... Love, Light & Happy Building! Rusty Cline, President: Monument Masonry, Inc.