Types of ground floors

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

1. Types of ground floors

2. Suspended Ground floor-1890’s
Joists supported on sleeper & external wall
Minimal ventilation
Rising Damp
No insulation

3. Ventilation for a suspended floor
Terra cotta air brick through wall

4. Improvements in design
Joists sitting on sleeper wall with attached
wall plate.
Incorporation of dpc to prevent rising damp
Sleeper walls built in ‘honeycomb’ style to
allow extra ventilation
Extra air bricks

5. Modern Timber Floors
Timbers are longer
Extra ventilation
Insulation incorporated

6. Suspended concrete floors
 Typical block and beam floor
Quick and cheap to install
Inverted ‘ T’ shaped beams
Concrete blocks placed in between them

7. Ground Supported floors
Solid ground of hardcore supports concrete
floor
Thick damp proof membrane placed under
concrete with a layer of insulation
Typical slab – 150mm with reinforcement

8. Upper floors
To provide extra stability for external walls
Joists built into wall
Chipboard typically placed on top of joists

9. Upper floors
Galvanised joist hangers are built into wall
Forms a ‘shoe’ or ‘seat’ for joist to sit in.
Modern prefabricated joists with metal
banding are now commonly used

10. Upper Floor
Chipboard upper floor with water proof
covering and taped joints