Building Homes or Extensions/horizontal extensions


I am planning to extend the floor area of the 3rd and 2nd floor of my house in a cantilever fashion for about 1.5 m. from the existing wall line. The concrete cantilever beams are 4.6 m apart although it only extends for .65 m. from the existing wall line. I a plan to use prefabricated concrete slabs to be put on top of the beams. How will I connect the slab form the beam? What would be the appropriate thickness of the cantilever beams so that it won't crack if rows of dowel is drilled into it? is the 4.6 m. beam to beam span enough to support a .15 m thick prefab slab?

If you would like to cantilever the floor, you should employ a structural engineer or other competent professional to design it for you. I couldn't give any advice on this without seeing detailed drawings and ideally I would prefer to visit the site. This is the type of job where you really do need the input of a professional.

Building Homes or Extensions

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Martin Owen


Anything relating to the design and construction of extensions and loft conversions.


I currently work as an Architectural Technologist for, where I design extensions and advise on legal implications.

Degree in Architectural Design and Technology

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