Masonry Magazine June 1979 Page. 11
SCAFFOLD SAFETY IS COMMON SENSE
By JOSEPH S. PUCCINELLI
Scaffolding & Shoring Institute
Introduction
Accidents don't just happen; there is always some underlying reason for them. And when they do occur, they touch the lives and pocketbooks of all concerned: the one involved, the family, and the employer.
For the employer there is considerably more at stake than the possibility of increased workmen's compensation costs. The morale and productivity of his people are adversely affected. Key personnel can be lost. The intangible costs of an accident can be very substantial.
What can be done to reduce these accidents? In the following paragraphs, such subjects as equipment, site conditions, bracing, loading, side brackets, platforms, rails, access, and accessories will be discussed to stimulate safe scaffold practice ideas.
Equipment
A safe working place cannot be achieved even if care is taken in erecting scaffolding unless the equipment is in good condition. Scaffold frames should be inspected before each use to assure that all locking devices are operable, the frames are not distorted or corroded to such a point that they are in a weakened condition, and welds are not cracked. In addition, all accessories should be visually inspected and cleaned as necessary, to assure that they are in good condition and are not damaged, corroded, or distorted.
Site Conditions
Preplanning is most important. If sufficient thought is given to where the scaffolding will be placed, site conditions, placement of material, etc., the job will progress smoothly and a safe working environment will be created. Productivity will also be increased, and this will increase profitability.
During the preplanning phase, it is essential to properly prepare the site. Footing and drainage trenches that have not been backfilled, large sewer or water excavations, basement ramps, etc., should be filled, leveled, and properly compacted before the scaffolding is set. Usually, this can be completed quickly and it will save considerable time in erecting scaffolding. Once the site has been graded and debris has been removed from the working area, be sure that the scaffolding is placed on a firm foundation. It is advisable to support scaffolding on mud sills, especially when the ground compaction is questionable or the job is of such a duration that inclement weather could disturb the scaffolding support.
Base plates are essential to properly distribute the scaffold load. It is also good practice to use leveling jacks. Leveling jacks are required if the nature of the terrain prevents the erection of a plumb, level scaffold.
If leveling jacks are used, begin scaffold erection at the highest point of ground elevation with the jacks adjusted to their lowest point. This procedure will provide maximum adjustment flexibility. Whenever erecting a scaffold, whatever the application or use, base frames must be erected in such a manner that all legs are vertical and ledgers are in the same horizontal plane. Patience in leveling and plumbing the base course will result in a uniformly erected scaffold, and will reduce total erection costs.
Bracing
Many schemes have been developed to brace scaffolds; these vary from job to job. Regardless of the bracing scheme, it is good practice to continuously brace the base course. This will provide a predetermined uniform scaffold spacing and will minimize possible overloading problems. Once the base course has been erected, methods such as alternate bay bracing or skip bracing may be used. A good rule of thumb is to be sure that every frame leg has at least one brace attached to it. In addition, the end bays should be braced continuously throughout the entire height of the scaffolding. Inside cross braces may be omitted on working levels only, and should be replaced as the job progresses.
Remember that as the wall is erected, 5-foot-wide (standard) scaffolding must be tied to the structure at the ends of runs, every 30 feet horizontally, and every 25 feet vertically. If the frames being used are less than 5 feet wide, the vertical tie dimension should be no greater than four times the minimum base dimension.
Ties must be both tension and compression members; that is, they should be strong enough to prevent the scaffold from tipping into the structure as well as away from the structure. It is best to use a rigid-type connection.
Base plates and screw jacks would have eliminated this obvious safety hazard.