1. Running a horizontal cable between 2 sockets (on same level) on walls either side of a 90 deg corner: For 2.5mm^2 minimum bend radius is a quite large 30mm - what is usual - hollowed out the corner to allow the cable to form an even bend? Avoid this route altogether? - Or some alternative?
2. Kitchen end wall has a 1.8m wide window & 0.6m wall at side. A double socket + 2 x single unswitched sockets (with separate fused switches) are needed - the single sockets to be below the window (behind wash m/c & dishwasher) & switches at side of window above the work surface: is this scheme OK?: Route the ring cable down wall to 13A double - continue to switch fuse(1) then to switch fuse(2) & then back up the wall. Spur cables from each switch fuse to go down and then left or right to respective unswitched 13A sockets. (Also - is a blank box required at the point where a spur cable changes from vertical to horizontal run?)
3. Wish to add a spur straight up a wall from a 13A socket into the attic for 2 separate convenience sockets on a daisy chain. Regs specify a 20 fuse spur (SFAIUI this can be with or without a switch?). Must the spur fuse box be adjacent to the source socket or can it be put in the attic?
4. 2.5mm cable through a single brick or block wall (plastered both sides): is 25mm plastic conduit a sufficiently good sleeve or is metal conduit better on basis it will transmit heat away better? What if there are 2 cables - do they need separate conduit?
Is an air gap needed in the conduit? Sealing at ends seems prudent to reduce potential smoke & sound transmission, but is that the correct procedure?
5. 2.5 mm cable through a cavity wall (formerly external but now internal) with 50mm cavity filled with mineral wool insulation. Is similar sleeving to 4. (above) correct or does something need to be done to remove surrounding mineral woool insulation & if so what/how?
6. SFAIUI FTE can be laid immediately above insulation, but what should the clearance be, sideways & below, from insulation before derating factors apply? ISTR a 100mm clearance is recommended, but cannot trace anything in the regs etc.
7. Need a socket on one side of a cavity wall. Is it OK to run the cable through the wall into a blank box (ie on the other cavity leaf behind the socket) and then straight up the wall into the joist space?
8. In one room the joists T into an RSJ which supports the dividing (block) wall. On other side the first joist runs lengthways (parallel) with the RSJ. What is best way to feed a 2.5mm cable around this obstacle? Thoughts are to bring cable up level with the top of the RSJ, feed through a 25mm conduit in wall, and run cable over the far joist in a notch to allow floor boards to lie flat. Is a steel plate or other protection needed over the cable in the notch?
9. An RSJ runs across the middle of a room supporting timber joists. There is 50mm clearance between the top of the RSJ & the underside of the floorboards. I need to get ring & lighting cables through here. As the finished clearance will be less than 50mm, does the FTE need to go into earthed conduit? If so what is the correct method of earthing this conduit? ie what type of clips, size of earth cable & to which earth point should it be connected - is a ring earth terminal OK? Does the RSJ need earthing when cable is run so close?
10. It is quite common to see FTE lying on top of plasterboard ceilings unclipped & unsupported between joists - is this still permitted by the regs (if it ever was)?
Sorry its a long one, but many TIA