Leaderboard

Thanks, Freddy; all noted. The ambiguity that has led to misunderstanding is your several references to 'screwing down', which to me firmly suggested the insertion/tightening of screws in a downward direction in situ (i.e. from the loft), which clearly was not the case. Yes, the fastening of two items together with screws can be properly described as 'screwing down' (as in 'screwing down a box lid') but would be better described as 'screwed together' or just 'screwed' (as in 'screwed and glued'). The suggestion of direction that 'down' imparts can be misleading, as in this instance, and really adds nothing to the narrative. But my apologies for persisting when perhaps I should have twigged things earlier - my original comment ('Arguably, screwed UP from the bathroom.') was really tongue-in-cheek because I could see the unintended impossibility of what you had said before and assumed merely a typo. Let's leave it there; we are both right! Are you not insulating the loft, e.g. with glassfibre or rockwool - with cables etc laid on top of that (or 'above' it if you prefer! )? If so, the protrusion of screws etc would not matter anyway. And that reminds me: as a cheap, virtually inert 'bulk' material, such insulation is very handy for other jobs, such as packing out pieces of plasterboard when patching in, part-filling deep joints before applying plaster etc or (mixed with filler) first-filling awkward crevices. And the fibres can add strength, much akin to horsehair-and-plaster. It is also obviously suitable for wrapping round pipes etc that might rub in a notch or masonry hole. I agree that MDF, in your location, might not be ideal. I don't however accept that using PVA as I envisaged is hazardous; it is an accepted primer (or admixer) for plastering/filling and, when thus incorporated or overcoated, ought not to react to moisture in the air any more than anything else you have used/installed. I wasn't saying that anything other than the exposed plaster infill should be so primed - but even if one did prime a board surface, it is little different to using an emulsion paint, which is similarly formulated. (I prefer to use a silk emulsion - or acrylic- paint on kitchen/bathroom ceilings to give a little more resistance to steam than a matt emulsion would.) And I do realise that your boards were not tapered and had been skimmed; my general suggestion for joining non-tapered boards is clearly not readily applicable in such a case (if skim etc can be cut back) but is very suitable in new work - I estimate I created about 80' of such 'substitute tapers' (i.e. 40' of butt joints) in my flat rebuild and was pleased with the result. As to the glazing panel, you now know what protection you missed. But good luck with the claim anyway.

We are in danger of falling out over semantics; I doubt you want that any more than I do. But, for the record, look in the middle of your penultimate post (why are there no post numbers?) and you stated: 'So ..... Screwed down from the bathroom then .... '. As to the latter part of my comment, I can see that it might be puzzling in view of the overall misunderstanding but I was simply indicating that the only screws you inserted and drove home from within the bathroom were those going up into the new ply patch - as your latest comments appear to confirm. As to your detailed procedure (thanks for that), I would only comment that your reference to 3mm x 20mm csk screws indicates that they are not PB screws. I assume you did not use 25mm PB screws (the shortest normally available) because you did not want to pierce through the ply. But would it matter if you did (unless the cat pricks its paws walking uninvited in the loft - which ought to be insulated anyway)? And using PB screws obviates the need for drilling and countersinking; as you know, the point and bugle head on a PB screw do this for you very well - but preferably with screws driven carefully by hand to get them just below the PB surface. A small further thought - MDF (ideally 12mm) is quite good for backing patches etc in this situation; easier to work with and unlikely to be bowed - and I usually have plenty of offcuts. One technique I have used successfully when either patching or butt-joining boards without two mating tapered edges is to plane, rout or scrape and sand away the surface of the board(s) to create the equivalent of a tapered edge (say 2-3mm deep and around 30mm wide). It is best if the board joint will be supported by a joist or noggin and abrading can be done before or after fixing (but, if the latter, any screws may need temporary removal to avoid fouling the cutting tool) and obviously needs care to avoid breaking up the board, although some irregularity or gapping is permissible. I then seal/bind the abraded surface with diluted PVA, allow this to dry and apply tape (preferably mesh, although paper can be used) and joint filler etc in the usual way. This avoids the need for the inevitable over-filling and feathering that a flush butt joint requires and can give a near-invisible finish (which I find is rarely achieved with feathering). My only choice (short of overall skimming) when boarding a ceiling that has its length and width both greater than that of a single board length. (Yes, I know that boards longer than 2.4m are made but not easily or conveniently obtained.) As to paying cash for personal shop purchases, you surprise me. A matter of choice, of course, but often hardly convenient and denying you the potential protection of section 75, Consumer Credit Act 1974. My guess is that you like to be anonymous when shopping in persona (wearing heels or not).