Floors Flashcards
In what 3 situations are suspended concrete slabs or block and beam floors used?
Where the ground:
- Slopes
- Has poor or uncertain bearing capacity
- Is liable to volume change (swells and shrinks)
What is the purpose of constructional concrete topping?
To spread the loads on the floor across the structure.
A reinforced concrete floor is typically what thickness?
100-300mm
The temporary supports for insitu concrete slabs are typically what two materials?
Timber or Steel beams and posts
In a Pre-cast concrete beam and block floor, the T-Beams are placed at what centres?
270mm centres
Concrete beams must have a minimum bearing of what?
90mm
What is a wall plate?
A continuous length of softwood timber that rests along the length of a wall.
Timber joists are usually around what thickness and depth?
Between 38 and 75mm thick & 75 to 235mm deep.
Timber joists are usually spaced at what 3 sizes?
400, 450 or600mm centres.
Floor boards for timber floors are usually what 4 thicknesses?
16, 19, 21 or 28 mm thick
Floor boards for timber floors are usually what 4 widths?
65, 90, 113 or 137mm wide
Floor boards for timber floors are usually up to what length?
Up to around 5m in length
What is timber strutting?
Short lengths of solid wood nailed between joists as a stabilizing method
What is an alternative to building in the ends of timber joist?
Using joist hangers
What is pugging?
A layer of plaster or sand placed between timber joists to reduce the transmission of airborne sound.
What is nogging?
Anogging is a strut used to give rigidity to a structure.
What are the minimum dimensions for nogging?
At least half the depth of the joist and at least 38mm thick.
What is the minimum height a DPC should be placed at in a wall?
150mm
In what situation is it better to build the ground floor slab into the wall?
Where appreciable movement in the soil is anticipated
Hardcore is typically how deep?
100-300mm
What should a DPM in a floor slab unite with in a wall?
The DPC
Vapour barriers should be used on what side of insulation?
The inside face or warm side
Pitch mastic and mastic asphalt are both impermeable to water and can therefore serve as what in the ground floor construction
A damp proof membrane
In suspended concrete floor construction, T-Beams are usually supported off what?
Brick or concrete sleeper walls
