Wall mounted steelworks are an acceptable and standard option of supporting telecommunications ancillaries, especially within urban areas where strict planning restrictions limit the use of lattice towers and monopoles. The ancillaries are typically mounted on steel support poles that are offset from the wall using steel brackets and/or stub arm to the wall.
The steelwork is connected to the wall via:
- Chemical resin connection – where anchors buried into the fabric of the wall.
- Mechanical connection – where anchors are put through the wall and fixed to backing-plates on the inner wall fabric.
The anchor design may use 2 or 4 anchor stud configurations per connection as per structural requirement.
There is a growing need to utilise existing wall mounted steelworks to support bigger and heavier antennas due to continuous technological improvements and ancillary upgrade to meet increasing demands. However, re-using existing wall mounted steelwork to support these bigger and heavier antennas is not without structural and health and safety concerns as evidenced by the increasing number of failures recorded in recent times.
These failures are partly due to inadequate structural assessment to account for increased loading from the proposed antennas/dishes. The proposed ancillaries may impose loads that are greater the design capacity of existing steelworks and associated connections to the wall causing failure.
The challenge is to define suitable methodology to structurally assess existing wall mounted systems to ensure safe reusability. We will discuss methods and solutions to this issue in more detail in the next blog.
However, the salient points for consideration when assessing these installations include:
- Inadequate original design (including reusability assessment) and proof testing of anchors to Construction Fixings Association (CFA);
- Insufficient spacing between top and bottom connections to wall;
- Mortar joints between bricks and/or block work;
- Cracked bricks and/or block work;
- Installation near wall edges and on mortar joints;
- Inadequate and porous resin around anchors and loosed bolts;
- Age and nature of building- natural degradation leading to loss of integrity of wall capacity and connections;
- Correct fabrication and installation of original steelwork and connection to wall.
KA Engineering Group not only completes structural due diligence for all telecommunication, subsea risers, onshore and offshore renewable wind turbines support structure, we also take further responsible steps to consider, advise, and optimise each site/field, ensuring cost effective design, installation, and maintenance for build contractors and efficient utilisation for operators.
Contact our expert team at: info@ka-engroup.com to learn more and discuss how we can best serve your needs.