Summary - lecture 9 - Waterproofing and stairs PDF

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Summary of waterproofing and stairs...

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BLDG1211 – Lecture 9

WATERPROOFING OF WET AREAS Materials for waterproofing: Walls - Fibre cement sheets - Plastic laminate sheets (Lamipanel) – have tile patterns imprinted upon them - Ceramilite (similar to Lamipanel) – both are merely glued to the substrate (timber/steel frame or brickwork). Joins are achieved by special joining strips - Prefabricated fibreglass shower/bath units incorporating the pluming and doors - Water resistant plasterboard – paper type substance Floors - Particleboard/plywood - Concrete - Compressed fibre cement sheet (have no edge tongue and grooving, require solid support along all edges. This means solid blocking should be installed under joints between floor joists – in a similar manner to standard solid blocking. This stops sheets deflecting different amounts, which stops tiles cracking) All the above require a membrane or shower tray of some type to be applied to prevent damage or water being transferred to adjoining materials and rooms.

Category 1 & 2 risk areas: - Two levels of risk area in a residence - Showers represent highest risk to water leaking into the structure whilst basins, baths, kitchens and laundries represent a lower risk Category 1-risk areas - For open showers with no shower curtain or door, waterproofing is required at a height of 1800mm with a 1500mm radius from the shower rose (head) - For showers with curtains or doors, waterproofing required 1800mm high and the area within the shower cubicle Category 2-risk areas - Lesser risks such as baths, vanity basins, laundry and kitchen sinks (outlets where water is contains within a vessel that is connected to a waste pipe) - For baths, waterproofing required at the junctions between bath and wall - For basins, waterproofing required 150mm above basin Materials - Grout

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o Wall tiles – must be 1 part Portland cement based grout which is compressible o Floor tiles – must be 1 part Portland cement and 2 – 4 parts sand mixed with water to a stiff consistency. Up to 1/5 lime can be added to aid workability o Proprietary cement based grout suitable for the tile type Sealants o Must be waterproof, neutral, self-curing, flexible, mould resistant and compatible with adjoining materials

Protection of shower flows in wet areas - Shower trays are to be the minimum of 150mm high, 75mm above the adjoining structural floor level or 25mm above the highest point of water containment within the shower - Membrane must be turned down into the drainage pipe A prefinished shower base - Have a fall of at least 1 in 60 (i.e. for every 60mm horizontally the floor drops 1mm vertically towards the drainage pipe) - Tiles may be glued or bedded in mortar Protection of walls in wet areas - Vertical wall junctions within showers must be flashed and the flashing must lap a minimum of 25mm into the shower tray - Vertical wall junctions must have a flexible sealant between the tiles to create a flexible movement joint - Wall tiles must finish over the floor tiles

DOMESTIC STAIRS Definitions of stair terms: - Flight – means that part of stair that has a continuous series of risers (includes risers and winders). Where a flight is interrupted by a landing or floor it is considered to be broken in to different flights - Going – the horizontal dimension from the front to the back of a tread excluding any overhang from the tread above - Landing – an area at either end of a flight or between two flights - Riser – the vertical height between consecutive treads - Spiral stair – a stair with a circular plan around a central post with treads that radiate from a common centre - Tapered tread – a stair tread that grows smaller towards one end - Winders – treads within a straight flight that are used to change direction of the stair, usually around a 90O bend.

Stair construction – BCA requirements

1. A maximum of 18 risers is allowed before a quarter landing is required. This is to stop people falling too far down the staircase (winders are the triangular steps in the corners where the fight changes direction. A maximum of 3 winders/quarter landing or 6 winders/half landing is allowed) 2. Dimensions of risers and goings throughout a flight must be constant except winders, which may vary from straight section of a flight. The winders must be constant with each other 3. Maximum 3 winders per ¼ landing or 6 winders per ½ landing area 4. Riser openings must not allow a 125mm diameter sphere to pass between treads 5. Nosings of treads to be non slip 6. Landings to be minimum 750mm long (if used on change of direction measured at 500mm radius from inside corner) 7. Slope maximum of 1 in 50 fall 8. Be provided where door opens to a change in walking level greater than 570mm (3 risers) 9. Minimum head clearance above nosing line – 2000mm

Balustrades - Stops people from falling sideways off stairs - Required to be 1 metre in length above landings - Minimum height of 865mm above nosing line of stairs - 125mm diameter sphere must not be able to pass between balustrades...