CANTILEVER BALCONY

Cantilever Balcony

Cantilever Balcony

Introduction

The most elegant means of support is to cantilever the balcony from the existing building structure. This can involve introducing steel beams between the floor surface and the ceiling of the level below to counter-act the load of the balcony. Insulated connectors form an integral part of this design to prevent 'cold-bridging' - a phenomena whereby a cold balcony draws heat from the building. Our engineers have a wealth of experience in designing cantilevered balcony structures. We use hollow section mild steel for columns because a high level of strength can be obtained from relatively small size. The columns are hot-dipped galvanised after manufacture and can be painted or powder-coated to suit the house. Supporting columns require a substantial concrete foundation which will be specified by our engineers [1].

Balconology has developed the Cantilevered Column to suit properties where a pure cantilever cannot be achieved but where columns on the external corners of the balcony will cause inconvenience or interrupt a view from windows below the balcony. Cantilevered columns are set against the wall of the house and have a substantial beam below ground to counteract the twisting moment of the balcony above. In some situations the cantilevered column can be recessed into the outer skin of blocks or bricks of a cavity wall then rendered over to completely conceal the steel supports.

Calculating Dead Load & Live Loads

Live Load consists of the weight of everything that will be on top of the balcony. This would include you, your family, friends and all the chairs, tables, grill and anything else. Dead Load consists of the weight of the balcony structure that sits on top of the posts[2].

An average balcony would be designed to handle a load of 50 psf (pounds/square foot) and is made up of 10 psf for the dead load and 40 psf for the live load. This is a minimum.

You have to know the load area for each post. Take the load area and look for its corresponding post size and height dimensions in the specified balcony size i.e. 2m x 1m in dimensions.

But to determine the load area you will have to do some basic math calculations:

Start with a simple rectangle balcony, 12' wide by 12' deep. The 12' wide side is attached to the house. Assume you would like to use 4 posts (you could use 3 if you preferred but let's use 4 for now).

The posts are at the 10' point in the balcony, out from the house where a beam will be positioned to support the balcony. So there will be a 2' cantilever beyond the posts and beam.

The two outside posts are positioned at the outside perimeter of the balcony and the 2 interior posts are positioned at the 4' and 8' positions respectively. So you have exactly 4' between each balcony post.

The distance between the house and the beam and post is 10', so the midpoint is ...