CSCS Roof Felting flashcards
CSCS Roof Felting · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Work at Height Regulations
- UK regulations requiring avoidance of work at height where possible, prevention of falls with collective measures, and mitigation of residual risk; a written risk assessment and rescue plan are required.
- Hot works permit
- A formal authorisation for torch work that specifies fire precautions, a fire watch during and for at least 60 minutes after work, and suitable extinguishers on the roof.
- LPG cylinder storage
- Cylinders must be stored upright, secured, away from ignition sources and never inside a building or below ground where gas can accumulate.
- Welfare facilities
- Drinking water, washing facilities, sanitary conveniences and a means of drying wet clothing must be provided on site for roof felting workers.
- Fall-arrest anchor point
- A suitably rated anchorage to which a harness and lanyard are attached; it is a last line of defence, not a substitute for edge protection.
- Manual handling of rolls
- Rolls over 20 kg should be lifted by two people or moved on a barrow or hoist; shoulder-carrying up ladders is unsafe.
- APP modified bitumen
- Plasticised bitumen membrane with good high-temperature and UV resistance, commonly used for torch-on cap sheets in warm climates.
- SBS modified bitumen
- Elastomeric bitumen membrane with good low-temperature flexibility and movement tolerance, suited to cold or movement-prone roofs.
- Vapour control layer
- A membrane placed below insulation in a warm roof to limit interstitial condensation; typically bitumen or polyethylene, lapped and sealed.
- Mineral-surfaced cap sheet
- A top-layer membrane with mineral granules providing UV resistance and slip resistance, used as the weathering surface of a felt roof.
- Lap widths
- Typical torch-on lap dimensions are 80–100 mm for side laps and 100–150 mm for end laps, unless the manufacturer specifies otherwise.
- Drip trim
- A metal edge trim fixed at the roof perimeter before the membrane is dressed over it, forming the finished drip edge.
- Substrate moisture check
- Testing the deck for moisture before felting; trapped moisture causes blistering and premature failure of the waterproofing.
- Timber deck condition
- Boards should be close-butted, fixed to joists, free from deflection and gaps within the specification before membrane is laid.
- Concrete deck preparation
- The deck must be dry, sound and free of laitance; a primer or bonding agent is applied before the first membrane layer.
- Finished fall
- The slope of the finished roof surface, typically 1:40 to 1:80 for flat roofs, checked before setting out to avoid ponding.
- Overlay system
- Laying new membrane over an existing roof using a carrier board or bonded system, only where the substrate is sound and specified.
- Torch-on bonding
- Heating the membrane underside and substrate until the bitumen is molten, then rolling to expel air and achieve a continuous 10–20 mm bleed at laps.
- Lap direction
- Side laps should face the direction of water flow so water runs over the lap rather than into it; end laps on successive layers are staggered.
- Mechanical fixing of base sheet
- Base sheet fixed with washers and screws at the specified density, with the cap sheet torch-bonded over the fixings.
- Over-torching defect
- Scorched or burnt-through membrane with exposed reinforcement; it must be cut out and replaced because it compromises waterproofing.
- Upstand height
- Membrane turned up a minimum of 150 mm above the finished roof surface, with a termination bar or chased-in edge at the top.
- Outlet collar
- A preformed collar installed before the main membrane so the membrane can be dressed into the outlet flange and sealed.
- Penetration detail
- Pipes and flues require a collar or sleeve with a minimum 150 mm upstand and a weathertight seal at the top.
- Termination bar
- A metal bar fixed at the top of an upstand or wall abutment, with a sealant bead, to prevent water tracking behind the membrane.
- Gas torch safety
- Check hoses and regulators, use a flashback arrestor, and never leave a lit torch unattended; keep leads clear of the flame.
- Edge protection dimensions
- Typical guardrails are set at 950 mm and 470 mm heights with toe boards, providing collective fall prevention at roof edges.
- Ladder angle and extension
- Ladders should be set at roughly a 1-in-4 angle and extend about 1 m above the landing point, secured against movement.
- Fragile roof surface
- Roof lights and asbestos cement sheets require a risk assessment and crawling boards or staging before anyone stands on them.
- Lap integrity test
- Probe or peel tests on sample laps confirm bonding; open laps are re-heated, pressed and re-rolled to achieve a sealed joint.
- Blister repair
- Cut out the blister to sound membrane, clean and prime, then apply a patch extending at least 100 mm beyond the defect, fully bonded.
- Ponding defect
- Standing water deeper than about 5 mm after 24 hours of drying indicates inadequate fall or a low point and must be investigated.
- Handover inspection record
- Photographs, location references, dates and test results compiled with guarantees and maintenance instructions for the completed roof.