Load bearing elements part5

College of North West London presentation; for the National Diploma in Construction

1. Traditional Building Load bearing Walls Part 5 February, 2012 John Fox, College of North West London Slide 1

2. Requirements For Lbw Strength & stability Weather protection Good thermal protection Fire protection Durability February, 2012 John Fox, College of North West London 2

3. Load bearing Walls L.B.W have 2 primary functions; To support the loads of suspended floors To support roofs February, 2012 John Fox, College of North West London 3

4. Load bearing walls A wall plate is fixed to the top of the wall The weight load is transferred to the wall plate and then laterally through the brickwork February, 2012 John Fox, College of North West London 4

5. Load bearing walls Suspended floors – on a typical domestic house, wooden joists are either built into the wall or supported by joist hangers, which in turn are built into the brickwork February, 2012 John Fox, College of North West London 5

6. External load bearing walls The 2 most common materials used in walling for domestic construction are: Bricks Blocks February, 2012 John Fox, College of North West London 6

7. Bricks Majority of bricks are made from clay Placed into plastic moulds Fired in a kiln February, 2012 John Fox, College of North West London 7

8. Bricks Bricks can be classified into 3 categories; Commons- used for general work which will be covered in render Facing brick- used where the brickwork face well be exposed Engineering brick- These are dense bricks with high compressive strength used for manholes, retaining walls etc. February, 2012 John Fox, College of North West London 8

9. Blocks These are classified into 2 types; Concrete- also known as dense blocks. Ideal for load bearing or party walls because of their density Good sound insulation value Good conductors of heat- not suitable for cavity work February, 2012 John Fox, College of North West London 9

10. Blocks Lightweight blocks- made form lightweight aggregates Generally used for internal skin on cavity work Light and easy to use Good thermal values February, 2012 John Fox, College of North West London 10

11. Mortar Mortar is the material that is used to bind the bricks & blocks together. Functions; Good workability Adequate bond strength Resistance to water penetration Resilience of thermal movement to masonry February, 2012 John Fox, College of North West London 11

12. Mortar Mix proportions; Soft sand- provides the ‘bulk’ of the mix Cement- acts as the binder and chemically reacts, hydration, with sand & water. As a result the mortar hardens. Lime- adds to the adhesion of the mortar February, 2012 John Fox, College of North West London 12

13. Loads on brickwork Brick walls have to be bonded in order to spread the load Most common type of bond is stretcher bond February, 2012 John Fox, College of North West London 13

14. Loadings over window openings There are 4 common methods of building over window and door openings; February, 2012 John Fox, College of North West London 14

15. Window openings Flat gauged arch- found more in high quality Victorian homes Segmental arch- found in low quality Victorian housing Wooden lintel- used mainly on Edwardian cheap housing February, 2012 John Fox, College of North West London 15

16. Loadings over windows On most housing projects today, catnic lintels are used Constructed of hard steel Insulation incorporated into the lintel to prevent ‘cold spot’ All catnics marked with safe working loads February, 2012 John Fox, College of North West London 16