Extension Knock-through

The final structural works when constructing an extension on a domestic dwelling is usually always the knock-through from the existing dwelling into the new extension. Amongst other structural calculations beamcalc.co.uk can provide you with Steel Beam Calculations for Domestic Extension Knock through in accordance with BS5950-1:2000.

Once the extension is built and watertight. The contractors will remove the rear load-bearing wall. This removal creates seamless integration between the existing dwelling house and the new extension.

Masonry Pier Design

In this particular example. We needed to design a special masonry column in accordance with BS5628-1:2005. This was due to the large, combined dead and live loads applied to the beam. The loads involved beam end reactions of around 80kN applied to the existing masonry. The existing masonry (in this case assumed 3.6N/mm² thermal blocks) was not strong enough to withstand the large, concentrated loadings and stresses from the beam. The masonry pier which was designed was constructed out of Class B engineering bricks. These have an unrivalled compressive strength. Our masonry design calculations for design vertical load resistance specified a Class B engineering brick with a compressive strength of not less that 50N/mm². BS 3921 requires that Class B engineer bricks should have a declared compressive strength of >50N/mm².

OUR STRUCTURAL DESIGN SERVICES ON THIS PROJECT CONSISTED OF THE FOLLOWING ELEMENTS

• • Design of the main knock-through steel beams from the existing dwelling into the new single storey extension, design of floor joist support beam and steel end plate connections in accordance with BS 5950.
  • Design of the concrete pad stones for the steel beam to sit on and masonry pier to support the dead and live loadings from the steel beam in accordance with BS 5628.
  • Design of new timber rafters for the new extension roof in accordance with BS 5268.