Scaffolding is used on most construction sites.
Therefore, it is important to follow health and safety rules when installing as well as using scaffolding, in order to reduce the risk of accidents.
At the outset, it should be remembered that scaffolding assembly can only be carried out by people with a scaffolding assembler’s license, and each scaffolding, after completion of the assembly before being handed over for use, should be approved by a person with a license in the construction industry.
Basic rules in scaffold installation:
- Each employee involved in the construction of scaffolding should read the assembly instructions provided by the scaffolding manufacturer as well as the scaffolding construction diagram. If conditions do not allow the use of standard solutions described in the assembly instructions, a design must be developed.
- Workers from the assembly brigade must be equipped with protective helmets and have equipment to prevent falls from height. These people must be at least 18 years old, have a current medical examination taking into account the performance of work at height, and, as I mentioned above, be certified as scaffold installers.
- Before assembling or dismantling scaffolding, the dangerous zone must be designated and secured by marking and fencing, which height should be at least 1.5 meters. The dangerous zone must not be less than 1/10 of the height of the scaffolding, but not less than 6 m.
- During the assembly as well as disassembly of the scaffolding, it is strictly forbidden to enter the scaffolding, except for the workers performing this activity.
- It is forbidden to erect and dismantle the scaffolding:
- at dusk, if lighting ensuring good visibility is not provided
- during dense fog, rain and snowfall and glaze
- during storms and wind speeds exceeding 10 m/s.
Safe scaffolding should have the following features:
Balustrades are the collective fall protection in scaffolding. Balustrades in system scaffolding, the balustrade consists of three elements, a handrail at a height of 1m, an intermediate handrail at a height of 0.5m and a board (curb) with a height of 15cm and a thickness of min. 2.5 cm located at the scaffold platforms. If the distance of the scaffolding platform from the building is more than 20cm, a balustrade should be used also on the inside. If it is not possible to use a balustrade, users and assemblers must use personal protective equipment, i.e. a set of harnesses with a rope, shock absorber and latch.
- Communication Risers:
Each scaffold must be equipped with communication risers. Communication risers should be made of communication platforms with a ladder at the same time as the scaffolding is erected inside its grid or, when required by construction conditions, as separate segments adjacent to the main part of the scaffolding. The distance between adjacent communication risers must not be more than 40 m, the distance of workstations furthest from the center of the riser must not be more than 20 m.
The scaffolding, which height exceeds in closed rooms four times, and outdoors three times the smallest dimension of the base, as well as the scaffolding equipped with transport booms and protective canopies must be anchored regardless of the results of static calculations. The scaffolding must be anchored to the wall of the building or structure in a way that ensures stability and rigidity of the structure and allows for the transfer of external forces acting on the scaffolding.
For anchoring, anchor connectors with hooks and anchoring elements ( screws with ears, plastic expansion pins) included in the equipment of the scaffolding should be used.
The number of anchorages, the arrangement of anchorages and the method of making anchorages in scaffolding are determined by the instruction or design.
When determining the number of anchorages, the following rules should be followed:
- anchorages should transfer horizontal loads parallel to the wall.
- anchorages should not transfer vertical forces.
- before starting the installation, it should be checked whether the wall will be able to carry the required forces of the anchorages.
- anchorages should be placed symmetrically over the entire scaffolding surface, relative to the vertical axes of the scaffolding.
- any fragments of scaffolding projecting beyond the corners of buildings or structures, which are exposed to wind, should be anchored additionally.
- wall scaffolding structure should not protrude beyond the highest anchor line more than 3m.
Every scaffolding made of metal elements and set up outdoors should be grounded and have a lightning protection system. The resistance of the grounding measured with alternating current with a frequency of 50 Hz should not exceed 10 Ω, and the distance between the grounding points should not exceed 12m. After grounding is installed, a qualified electrician should prepare a protocol of resistance measurement.
- Protective canopies and grids:
Scaffolding located in an area where it is not possible to designate a hazardous zone requires additional solutions. One of them are protective canopies and nets. The task of protective canopies is to protect people, property from uncontrolled falls of objects that may be on the scaffolding. Canopies are used in compact urban construction, along traffic routes, passageways, sidewalks and streets. The minimum distance of the canopy from the ground level is 2.4m, however, the height of vehicles with cargo that may move nearby should be taken into account.
The size of the canopy overhang is determined by the PN-M-47900-2 standard, which recommends that for scaffolding up to 20m the canopy overhang (measured in a perpendicular direction from the outer edge of the scaffolding) should be 2.2m, and above 20m 3.5m. System scaffolding components such as consoles, braces, pipes, joints and platforms can be used to construct the canopy. The end of the canopy must face upward at an angle of 45֯.
Safe use of scaffolding:
- When performing work on the scaffold, the permissible working load of the platform must be complied with. A notice indicating the permissible load capacity of the scaffold platform should be displayed in a visible location on the scaffold. Overloading the scaffold platform with materials beyond its capacity and gathering of workers on the platform is strictly prohibited.
- Materials on the scaffolding should be stored in a safe manner that prevents falling off and free passage.
- The technical condition of the scaffold must be checked by carrying out inspections.
The following inspections are carried out during the use of the scaffold:
- daily inspections by the foreman using the scaffolding.
- decennial inspections performed every 10 days by the scaffolding maintenance technician or an engineering technician using the scaffolding.
- ad hoc inspections performed by a committee with the participation of the site manager, master builder and foreman using the scaffolding.
During the inspections it is necessary to check:
- the condition of the scaffolding connections.
- the condition of safety devices (railings, curbs).
- condition of platforms (damage, cleanliness of platforms).
- passageways (correctness of closing and opening of exit hatches, attachment of ladders).
- condition of winches and support structure.
- condition of anchorages.
- the condition of swivel and cross joints.
The results of each inspection should be entered in the construction log.
After any break in work lasting longer than 10 days, after any storm, downpour or heavy snowfall, check whether:
- the scaffolding has not been distorted or damaged.
- foundations have not been washed away.
- anchorages have not been damaged or loosened.
- safety devices such as protective canopies, platform protection, fences and bumpers at crossings have not been damaged.
- phenomena affecting the strength and stability of the scaffolding have not occurred.
- electrical conductors running in the vicinity of the scaffolding are protected in accordance with the regulations regarding electric shock protection or disconnected from the voltage.
- lightning protection devices have not been damaged.
- there are no cracks in pipes, welds, or planks of the working platforms.