Building Regulations

Structural calculations are generaly prepared to support Building Regulation Applications for situations that are outside the scope of Approved Document A. Typically these are

  • Steel, timber or concrete beams
  • Splice and steel connections
  • Raised collar roof structures
  • Portal and box frames due to substantial removal of shear or cross walIs
  • Vaulted Ceilings with hip ends
  • Loft Conversions
  • Non Standard Roofs
  • Bridging Sewers
  • Pad and beam foundations
  • Raft foundations
  • Building in Close Proximity to trees in clay subsoil.


Due to fashion trends and the need to use all available space it has become common to locate living accommodation into the roof space. Loft Conversions are good examples of this but more recently vaulted ceilings have become fashionable together with the inclusion of rooflights. Depending upon the configeration of the roof this may effect the tying of the roof structure and specific structural design will be necessary.

In the example below the steel beam has been designed to span horizontally as a ring beam to resist the horizontal force generated by the untied rafter feet

roof structure

Bridging Drains and Public Sewers

Bridging drains within the foundations has always been an everyday practice within the building industry. However since October 2010, when all common drains were re defined as Public Sewers bridging sometimes requires an engineering approach. Most Water Authorities insist upon a minimum of 600mm working space either side of the public sewer. Generally, two 150 x 100 ground specifcation concrete lintels will suffice, but occaisionally this 1200mm of bridging may be required to support a column or the drain may pass through the corner of the building in which case a design will be required. In addition to the Local Authority the Water Authority will need to check the design and the specification to ensure it complies with the WAA specification.

bridging public sewer


Steelwork Splice Connections

These are advantageous and necessary for the following reasons;

  • for easy transport
  • to allow ease of erection
  • to be designed to fit into the structure
  • located in position where the bending stress are a minimal.
  • to be easily assembled on site
Steel Beam Splice

The above connection is one of two common splices, the other being an end plate to end plate connection.

Where the bending moment is relatively low and the beam is deeper than 150mm this type of connection may be a good choice. However, this type of connection is frowned upon in some circles and we share their concern, but where the loads are low there is no reason why an end plate to end plate connection cant be used. Loft conversions are a good application as the loads imposed upon support members are light.The connection is limited by the tension within the bolt and the bending in the plate. As a general rule the end plates will not be less than 20mm and 4/8 bolts of 20mm diameter.