What Are Reasonable Spans of Carriers made of Various Materials
At this part a simple example of a carrier which connects one wall of the house with the other as can be seen in figure 1 is presented. For simplicity the carrier is loaded in its middle with a sandbag. Exactly the same loading would be present if the roof was mounted at this point.
For reasons of simplifying future calculations and understanding the above figure 1 is remade and represented as in figure 2
For the start it is Importatnt to remember that the allowable span which a carrier can have so that it will not collapse depends on three important factors:
+ its cross-section geometry (see examples below in the geometry part)
+ its material (steel, wood or reinforced concrete)
+ on how you will apply the load on it (is the weight in the middle of the carrier or at one side)
Remember: NEVER use concrete or similar materials like stone without reinforcements of steel or similar for a carrier! The possibility that it will colappse is almost certain!
You can see an overview of a common problem involving a carrier as it would be used for a roofing or for hanging other loads for instance meat.
to be CONTINUED........ Notice: The author accepts no responsibility for the safety of a construction or the correctness of the article
--HTP Petros 15:57, 13 January 2010 (UTC)