Pull Tests
Pull tests: are typically preformed to assess sheer pull force. It involves attaching a suitable pull tester to the anchor or fixing which is then put under tension to the design stress load level, this determines how strong and secure the fixing is.
A scaffold tie is an important connection that fastens the scaffolding to a building or structure to prevent collapse. The ties enable a resistance to forces trying to pull the scaffold away from the structure such as high winds. Tie patterns are determined by a design engineer on a bespoke scaffold and are outlined on the manufacturers guidelines and in the code of practise for system scaffolds, however if the anchor ties are installed incorrectly or even installed correctly into weak material they will be compromised and fail hence the importance of onsite pull testing.
The substrate must be capable of taking 1.25x the working load of each anchor. A minimum of three anchors, or 5% of installed anchors are tested per scaffold, best practice would be to spread the anchor testing throughout the scaffold, should a scaffold tie fail then the pull test frequency doubles, the frequency doubles again should a second anchor fail, should more than two of the anchors fail 100% of the anchors will require testing.
Swift scaffolding provides a pull testing service free of charge for any scaffolds they erect if the project requires and are also able to accommodate site visits to pull test scaffolds erected by other qualified scaffolders. Results of pull tests are formally recorded and should be retained with the safety documentation relating to the scaffold structure.