Layout of frames

• Layout with columns as closely spaced as the nature of the building permit will result in short span beams or trusses . 
• With smalle rspans , the beams reduce in size & cost . This will also be true for columns because of the reduced loads they carry . 
• The spacing of the frames is influenced largely by the economic span of the floor or roofing system which they support . This will vary with the imposed floor or roof loading & the type of floor or roofing system 
• In the case of building frames & rigid frames where the frame beams increase in span or frame columns increase in height , there comes a point at where it may be more economical to increase the spacing between the frames . 
• This will result in increased loads on the beams but reduced numbner of frames . 
• in the scase of shed frames , unless the trusses are of considerable span , a close spacing of the frames usually gives the cheapest structure . 
• The layout of a ske;leton structure should be based on a regular structural grid . 

Advantages of a regulat structural grid are L 

1. Loads on the structures are transmitted evenly to the foundations , thuis minimizing relative settlement & standardizing the sizes of foundation . 
2. It results in regularity in beam depths & column sizes & in the position of column & beams relative to the wall . in the cae of reinfoced concrete , this will standardize the formwork used . It also standardizes the size of enclosing walls or panels . 
3. in reinforced concrete work , the regular slab & beam spans minimize the variations in reinforcement sizes . 
4. It permits greater re-use of formwork . 

There are 2 types of building frames to be discuessed in this syllabus which are 

1. Steel frames - using either hot -rolled steel sections or cold formed steel sections . 
2. Timber frames . 

For steel frames , the columns are usually referred to as stanchions .