Masonry, the art and craft of building or fabricating with stone, clay, brick or concrete block, is one of the oldest of the skilled trades. It dates back to the use of sunbaked clay brick more than 6,000 years ago. Masonry construction helped build some of the world’s most notable structures, including the Egyptian Pyramids, the Roman Colosseum, the Taj Mahal and the Great Wall of China. Read more
If you work in masonry, you know you have to be exacting every day. But, as you build structures with your hands, it’s equally important to put some resources into improving occupational health and safety. Read more
Preventing Risk and Liability for Contractors
The construction business is a dangerous one. There are risks for illness and injury at every turn. Any contractor needs to take precautions to mitigate these risks and save themselves great cost in liability, manpower and efficiency. Failure to include the right policies and procedures can cost hundreds of thousands of dollars in fines and damages. Here’s a look at how contractors must be aware of these issues and how proper masonry contractors insurance can protect you, your business and your workers from disaster.
Maintaining proper safety standards is the first thing a contractor can do to defend against the costs of accidents and injury. Some contractors make the mistake of believing that guidelines put in place by the Occupational Safety and Health Administration (OSHA) are onerous and unnecessary. Nothing could be further from the truth.
OSHA standards are sometimes stringent, but they are important. These regulations are in place to protect workers from harm. Not only are they vital for maintaining safe work conditions, but they are the law. Contracting businesses who fail to obey them can be subject to fines and other censures from the organization.
Heavy equipment such as mixers are a fact of life on masonry job sites. It is vital to ensure that all employees and workers are properly trained and educated in the policies and procedures involving the use of heavy equipment. Safety zones should be established to keep unauthorized persons from the area of the equipment, and only those completely trained and certified should use the equipment.
In all cases, anyone on a work site where heavy equipment and machinery is in use should wear the proper personal protective equipment (PPE). This varies by equipment but could include hard hats, safety suits, gloves, boots or other pieces of protective clothing.
Hazardous materials aren’t common on masonry jobs, but situations can arise where asbestos, lead and other substances may be encountered. Follow OSHA guidelines in dealing with these substances to the letter. This includes the use of HEPA filters, respirators and other PPE indicated based on the substance that could be encountered. All workers should be properly trained and educated in safety policies and procedures. Regular updates in this training should be scheduled to make sure everyone is always up to date.
No matter how careful you are, accidents happen. The best way to manage liability issues is to carry a proper and complete masonry contractors insurance policy. This can include workers compensation, vehicle insurance, accident and liability insurance, and a variety of other coverage options that may vary from business to business and even job to job. The right insurance can make the difference between helping an injured worker get back on their feet, and going out of business.
As we explained in our last post about cold weather masonry work, the 40°F-mark is important when it comes to working with mortar. It’s important to keep the mortar heated above 40°F, but it’s understood that you can’t always control the air temperature (at least not easily). Here are some important steps to take if you’re doing masonry in winter:
- If the temperature is above 32°F, cover the walls with plastic to prevent water from getting into the masonry.
- If the temperature is between 32°F and 20°F, cover the walls with 1/2-inch insulation blankets to prevent or reduce rapid heat loss and to block water from getting into the masonry.
- If the temperature is between 20°F and 0°F, cover the walls with 1-inch, plastic insulation blankets, or maintain a heated area to 40°F for two days after the installation is complete.
It is important to only mix the mortar as you need it, so that it doesn’t become too cold before you use it. If the temperature of your mortar dropping too low becomes a concern, you can keep it warm by placing it on a heated surface, like a metal mortar board. Make sure that you keep an eye on your mortar if you’re trying to warm it, because excessive heat may dry it out.
The following tips apply for all masonry in winter being done in 40°F temperature or colder, or when the temperature of the masonry itself is below 40°F:
- Always heat sand or water to produce mortar above 40°F.
- You can use heat sources on either or both sides of masonry while it’s under construction.
- Install wind breakers if wind conditions exceed 15 miles per hour.
- Do not lay glass unit masonry in cold weather.
- Try to work inside heated enclosures when the temperature drops below 20°F.
- Beware of commercially-produced “antifreeze” admixtures for masonry work, because they are oftentimes just accelerators and not freezing-point depressants. Be sure that the admixtures that you are using are approved for the work you’re doing.
- If temperatures fall below freezing, and you experience frozen lumps in your work, you may need to heat sand in order to thaw the lumps.
- Always add cold sand to heated water in the mixer before adding cement to avoid flash setting.
- If masonry units are below 20°F, or have frozen moisture, visible ice, or snow on their surfaces, do not lay them.
- Although very high absorption fired-clay brick may need to be wetted prior to use, all masonry units should be kept dry before you’re ready to use them.
It doesn’t look like anybody’s going to be working outside today in New York! However, in the weeks to come, it’s important to be mindful of the extra precautions you need to take while working in winter weather. For masons, it’s especially important to be aware of the temperature around 40°F, because once it drops under 40, there is special cold weather masonry protocol they should follow.
Much like we discussed when we looked at cold weather concrete, the hydration process in the mortar is slower than usual in cold weather masonry work. When the water in the mortar freezes, mortar expansion occurs, which is a destructive change in the mortar’s volume. The expansion in any mortar that is more than 6% water is enough to crack the mortar and damage the job. The architect or engineer should specify how the masonry should be wetted if it needs to be rewetted, and should also specify how the masons should test to confirm that the procedure was successful. Remember that wet or icy unit surfaces make it difficult for a firm bond to be made between the unit and the mortar.
Tips for Cold Weather Masonry Work
- It’s helpful to use a speed hydration method, such as using high-early cement or by using an accelerator. Beware that using type III cements may potentially change the mortar color, which can affect the required appearance for your job.
- Be mindful of how admixture could affect cold weather masonry and reactions.
- All masonry materials need to be protected from the elements, especially from being wet by rain or snow. Protect all materials by placing them on planks and covering them with tarps when they’re not being used.
- Consider which of your masonry materials may need to be heated prior to using them in order for cement hydration to properly occur.
- If you’re trying to accelerate stiffening, use masonry units with high rates of absorption.
- Although calcium chloride is often used as an accelerator in concrete (at a maximum of 2% by weight of the cement), it is strictly forbidden to be used in mortar by the Specification for Masonry Structures (ACI 530.1-95/ASCE 6-95/TMS 602-95).