load bearing elements part5
DESCRIPTION
College of North West London presentation; for the National Diploma in ConstructionTRANSCRIPT
Traditional BuildingLoad bearing Walls
Part 5
February, 2012 John Fox, College of North West London Slide 1
Requirements For Lbw
Strength & stabilityWeather protectionGood thermal protectionFire protectionDurability
February, 2012 John Fox, College of North West London 2
Load bearing Walls
L.B.W have 2 primary functions;To support the loads of suspended
floorsTo support roofs
February, 2012 John Fox, College of North West London 3
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
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
External load bearing walls
The 2 most common materials used in walling for domestic construction are:
BricksBlocks
February, 2012 John Fox, College of North West London 6
Bricks
Majority of bricks are made from clayPlaced into plastic mouldsFired in a kiln
February, 2012 John Fox, College of North West London 7
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
Blocks
These are classified into 2 types;Concrete- also known as dense
blocks. Ideal for load bearing or party walls
because of their densityGood sound insulation valueGood conductors of heat- not
suitable for cavity work
February, 2012 John Fox, College of North West London 9
Blocks
Lightweight blocks- made form lightweight aggregates
Generally used for internal skin on cavity work
Light and easy to useGood thermal values
February, 2012 John Fox, College of North West London 10
Mortar
Mortar is the material that is used to bind the bricks & blocks together.
Functions;Good workabilityAdequate bond strengthResistance to water penetrationResilience of thermal movement to
masonry
February, 2012 John Fox, College of North West London 11
Mortar
Mix proportions;Soft sand- provides the ‘bulk’ of the
mixCement- 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
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
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
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
Loadings over windows
On most housing projects today, catnic lintels are used
Constructed of hard steelInsulation 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