How To Brace A Masonry Wall For Repair
July 25, 2005 nine:29 AM CDT
Bracing Masonry Walls
By
Every bit a mason contractor, how many nights have you laid awake at 3 a.m. with the wind bravado against your bedroom window? Y'all tin't sleep considering you lot know you take masonry walls up that may not be braced, and you are wondering if the wind will blow any of these walls over. You lot hope that your foremen accept properly braced these walls, just you haven't been enforcing them to do so. In fact, the truth of the thing is you haven't taken bracing requirements that seriously until tonight, when the air current is blowing against your window. The next morning, you lot phone call your foremen to run into if your walls are braced. Past now, it is too late. If they weren't braced, chances are y'all may have lost some walls.
Or possibly y'all take had an experience like I did just last summer. On a Saturday night during a weekend camping trip, I was sitting effectually the bivouac, drinking beer with some friends, and making plans to play golf the next forenoon when my mobile telephone rang. It was the superintendent at 1 of the Wal-Marts we were edifice. He informed me that we had a block wall blow over. Luckily, it blew over when at that place were no workers onsite, and no one was hurt. So the side by side morning, instead of going to the golf course, I had to caput up to the job site to assess the impairment. What a manner to ruin a camping ground trip!
In writing this commodity, it is my hope that the likeliness of one of your masonry walls falling down will be reduced. And if information technology does happen to you, that yous follow the proper steps and then that no one gets injured or killed, and you volition go compensated for cleaning upward and rebuilding your walls. With that being said, I am going to explicate the most critical points of wall bracing, I promise, in simple bricklayer'southward terms.
The Standard Exercise
For years, the masonry industry had only the OSHA regulation to follow for wall bracing. The OSHA regulation dictated that "all masonry walls over viii feet in height must be adequately braced." That was it! With this regulation, as long as your walls had some kind of bracing on them and they didn't accident over during construction, you were "adequately" braced. On the other mitt, if you were braced for a xl-mph wind and your walls blew over due to a 60-mph wind, your walls were deemed "inadequately" braced. This obviously proved to be quite a gray expanse of estimation.
The Mason Contractors Association of America (MCAA) recognized this predicament and formed the Council for Masonry Wall Bracing, a group of masonry experts including contractors, engineers and masonry pattern professionals. In 1999, the Council introduced the Standard Do for Bracing Masonry Walls Under Construction, or Standard Exercise. This Standard Do lessens the risk of lost production, loss of money and most importantly, the potential loss of life.
First and foremost, the Standard Practice establishes life rubber as its principle goal. From a practical betoken of view, information technology recognizes that ? under some rare circumstances ? information technology is incommunicable to prevent walls nether construction from blowing downward. So, the Standard Practice does non totally protect from holding loss, but it does provide mason contractors with the knowledge on how to prevent injuries due to wall failure.
Secondly, if OSHA were to come up on your task site and you were post-obit the Standard Practice, y'all would most probable not exist cited or fined because this is an "industry standard" and, in most cases, OSHA recognizes it.
Following the Standard Practise likewise provides an actress bonus. Mason contractors often tell me that the owner or general contractor is requiring them to caryatid their walls so oft that it is ridiculous and almost impractical to build due to the extra toll of bracing. I always tell them that if the bracing is in your part of the contract and the general contractor or owner is requiring actress bracing that goes beyond the Standard Practice, the owner or full general contractor should accept to pay for the actress expense in the course of a modify gild. Otherwise, you may lose your tail on the project due to the toll of installing the actress bracing. This is one reason why it is so important that you lot sympathize non only your part of the contract, but also the Standard Practice.
Know Your Zone
Commencement, the mason contractor is responsible for establishing and maintaining the "Restricted Zone," too known as the "Express Access Zone," on each side of the wall subject field to the upshot of a masonry wall collapse. When scaffolding is up, the Restricted Zone is on the side opposite the scaffolding and must exist cautioned off from the wall out at the distance of the wall height plus four feet. However, once scaffolding is removed, the Restricted Zone must be maintained on both sides of the wall.
A bricklayer contractor who's thinking alee will designate the Restricted Zone area early on on based on what the total, completed height of the wall will exist when finished. This fashion he or she tin avoid setting up caution record and and then later having to move information technology. For example, if your wall volition be built to a summit of 24', it should be cautioned off at 28' as before long equally the wall becomes over 8' loftier. Without the proper planning, the expanse would have to be cautioned off at 12' when the wall becomes 8' loftier and moved out every bit the wall gets college. Why spend product time revising boundaries?
Fourth dimension Periods
The Standard Do states that during the "Initial Period" of construction, masonry piece of work is immune to go on as long equally wind speeds do not exceed 20 mph. The Initial Period of time is limited to a maximum of one working mean solar day, during which the masonry is being laid above its base or the highest indicate of bracing. When the work is finished for the day, or when a specified height of wall is reached, that portion of the wall must exist braced.
During the Initial Catamenia of structure, just those employees who are pertinent to the construction of the wall are immune in the Restricted Zone. This includes any of the stonemason contractor's employees or, allow's say, an electrician who is responsible for putting conduit in the wall equally it is being built. A plumber installing water lines adjacent to the wall is not pertinent to the construction of the wall, therefore he or she would not be able to install those lines in the Restricted Zone during the Initial Period of construction.
The "Intermediate Period" of structure is the time following the Initial Menses until the wall is connected to structural frame elements, floors or roofs or adequately internally braced. Cross walls and pilasters can also serve equally stability so as to permit braces to exist removed at those locations. Intermediate Catamenia bracing must remain in place until final lateral stability from supporting structural elements is in place. During the Intermediate Catamenia, the Restricted Zone must be evacuated at air current speeds of 35 mph or higher.
Bracing Basics
When bracing masonry walls, a minimum of two braces is required per wall console (the altitude between control joints). Using two braces per panel is important because with only one brace per panel, the wall tin wobble in and out at the control joints and snake in the winds. The maximum permitted length of wall between control joints is 25' per national Edifice Codes. Any length over 25' is accounted illegal and should not be built every bit information technology is a violation of building codes. (A good rule of pollex is to encourage your builder to put control joints at 24'eight" apart, if possible, since block tin can be laid out to that distance without cutting.)
Braces must exist installed with 20% of the wall outside of each caryatid at the command joint. The easiest way to figure this is to take the panel length and multiply past .2. For example, a 25' long wall multiplied by .2 would exit each brace located at 5' from the command joints and 15' between the braces.
Brace heights vary based on which menstruation of structure the wall is in, the weight of the units you are installing, and your method of grouting.
Go on in heed that a masonry wall is considered to be reinforced 12 hours after the grout is placed. So if y'all are low-elevator grouting as the masonry is existence laid, your walls will be braced much more sufficiently internally. This is due to the grout having time to prepare while you are laying the side by side four to six feet of wall higher up information technology. Once the grout in the wall reaches that 12-hr mark, the masonry wall enters into the Intermediate Flow, and lower braces can exist moved up based on the Standard Do.
In addition to the Standard Practice, another good source of information is the MCAA's Masonry Wallbracing Design Handbook, which has over 700 schematic examples of wall bracing.
Monitoring Wind Speed
Lang Masonry Contractors have wind monitors on each job site to measure the current of air speed. These air current instruments, called anonometers, toll betwixt $lxxx and $200 and are well worth the investment. Some volition even sound an alert when the established wind speed is exceeded.
If y'all do not have these instruments onsite, you may use the visual method of measuring air current equally long as you have trained your people how to measure out visually based on the Beaufort Current of air Calibration (BWS). Still, if you apply this visual method to measure out, evacuation times change due to the decrease in accurateness of the visual method.
| The Beaufort Wind Calibration | |||
| Beaufort Number | Current of air Speed (mph) | WMO* | Appearence |
| 0 | Nether 1 | Calm | Smoke rises vertically |
| ane | 1-3 | Light air | Smoke migrate indicates wind management |
| 2 | 4-7 | Calorie-free breeze | Wind felt on face, leaves rustle |
| 3 | 8-12 | Gentle cakewalk | Leaves and twigs constantly moving |
| iv | thirteen-18 | Moderate cakewalk | Dust, leaves lifted, small tree branches motility |
| v | 19-24 | Fresh cakewalk | Small-scale copse in foliage begin to sway |
| 6 | 25-31 | Strong breeze | Larger tree branches move, whistling wires |
| 7 | 32-38 | Near gale | Whole copse moving, resistance felt walking against wind |
| 8 | 39-46 | Gale | Whole trees in motion, resistance felt walking confronting wind |
| 9 | 47-54 | Stong gale | Slight structural damage occurs, slate blows off roofs |
| x | 55-63 | Storm | Trees broken or uprooted, considerable structural damage |
| 11 | 64-72 | Violent storm | Wide-spread damage |
| 12 | 73 and over | Hurricane |  |
| * Earth Meteorological Organization | |||
Using the BWS method, evacuation in the Restricted Zone changes from 20 mph to 15 mph for the Initial Period. This is considered a moderate breeze, where thin branches on copse move or dust and paper rises. During the Intermediate Period, evacuation of the Restricted Zone changes from 35 mph to 30 mph using the BWS method. This is considered a strong cakewalk, where large tree branches begin to motility, open wires (e.g., power lines) begin to whistle, and umbrellas are difficult to keep under control.
The BWS method may sound crazy, but it works. When compared to bodily current of air instruments, information technology is astonishing how close you can decide the wind speed.
Remember: If you are using the BWS method and an OSHA inspector comes on your job site, exist sure your Responsible Person ? the person who has been trained on how to ready and monitor wall bracing, maintain the Restricted Zone, too as monitor wind speed ? makes them aware that you are measuring the wind using this method.
Notification
Once your people are following proper bracing procedures, notification is the next important part.
For instance, allow's say other trades are working in the Restricted Zone during the Initial Menstruation and decline to stay out. Or, you put your braces up and other trades have taken them down ? equally was the instance of the wall we lost on the Wal-Mart concluding summer. If other trades are working in your expanse during the Initial Period, your Responsible Person must notify the general contractor'south superintendent of the Restricted Zone requirements during that time period.
If other trades accept your braces down, make sure your foreman or Responsible Person notifies the general contractor's superintendent that the braces must remain in place until the walls are connected to the structure. In both cases, I recommend your foreman as well puts this in writing.
As well, if the Responsible Person is not able to be onsite, he or she is responsible to notify the full general contractor's superintendent of the Restricted Zone during the Initial and Intermediate Periods and how to monitor wind speeds so that the Restricted Zone is evacuated if the wind speed exceeds the twenty mph (Initial Menstruation) or 35 mph (Intermediate Period).
Be Prepared and Have a Plan
Being a mason contractor myself, I know that a tremendous amount of time can be saved when y'all have a plan for bracing walls before construction is started. As long as your people know the locations to install braces and dead men as the wall is being built, bracing becomes much easier and quicker. This niggling bit of preparation can save the stonemason contractor a tremendous expense in the long run.
Conclusion
Equally a stonemason contractor who realizes that bracing masonry walls is so important for the safety of workers onsite, I promise this article has helped clear the water a little for you. And earlier the next big wind blows against your bedroom window, I hope y'all have taken the time to study the Standard Practice for Bracing Masonry Walls Under Construction and properly train your crews on wall bracing. If you have, y'all tin but ringlet over and go dorsum into a peaceful slumber. If you oasis't, counting all of the sheep in the earth won't help.
About the Writer
Damian Lang is a mason contractor in southeast Ohio and inventor of many labor saving masonry systems and products. Lang has served every bit the Marketing Commission Chairman for the Mason Contractors Association of America. He is likewise author of the book Rewarding and Challenging Employees for Profits in Masonry. To network with Damian on contractor tips or tips you have and would like published, contact him at dlang@langmasonry.com or 740-749-3512.
This article is not intended to provide engineering advice, but to heighten issues on masonry wall bracing. Although the author is the manufacturer of a bracing system, bricklayer contractors and their employees should consult the Mason Contractors Association of America'due south Standard Practice for Bracing Masonry Walls Under Construction, the MCAA, an engineer or the manufacturer of their wall bracing organization regarding their wall bracing bug. Proper wall bracing will vary depending upon the type of bracing used, job site conditions and other engineering factors.
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Source: https://masoncontractors.org/2005/07/25/bracing-masonry-walls
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