Willl Posted January 26 Share Posted January 26 Hi, I will be having a hip to gable loft conversion with a dormer on the back and am unsure what to do about the roof at the front. Presently, I have an agreement with the builders that they will replace any damaged slates they find but I don’t want to regret not having the roof redone while scaffolding is up.. It is an old slate roof, with no felt or similar underneath. I have had problems in a couple of places at the back, where slate has slipped leaving gaps and consequently water damage to the ceilings below. I haven’t had these problems at the front. My thoughts are to ask the builders for a price to carefully remove the slate on the side and back (keeping any that are good) to then remove the tiles on the front and then lay a breathable membrane, before retiling using the existing good tiles. I’m guessing batten will need to be replaced in places.. A sizeable job with a sizeable cost I’m guessing.. Any opinion on if I should just stick to the agreement to replace damaged slates? The hip to gable section of the roof will be retiled as part of the conversion and two large Velux windows will be fitted. My understanding is that it is often the nails that fail, rather than the tiles themselves, so should I try and have an agreement that the roof is assessed overall and loose slates made secure? My primary worry is water coming through, with this no longer coming straight onto the ceiling, I’m guessing this would be onto the insulation that is required to be fitted above the plaster board. Is it possible to have insulation that would do a similar job to the membrane and give a certain level of protection from water ingress? Lastly, if I did have retiled with a membrane would it be possible to insulate as a warm roof and therefore save some head height in this part of the conversion? The rafters are 100mm so I understand for a cold roof, insulation would need to be added into what would be head height. Apologies for any ignorance displayed here and thanks in advance for any opinion and advice! Will Link to comment Share on other sites More sharing options...
bassanclan Posted January 26 Share Posted January 26 When roofers are removing the slates they will be scrap. If they take care to remove carefully it could be twice the labour, so twice the cost! The same with battens. If it is going to be a habitable room after the work is done then it is well worth doing it now for piece of mind, because a water damaged room is a lot more costly to repair than a water damaged loft 3 Link to comment Share on other sites More sharing options...
Willl Posted January 26 Author Share Posted January 26 Understood; with the age of the roof and the house I'm presuming it is old Welsh slate we have and that is what has made me think about trying to keep it.. Thanks, Will Link to comment Share on other sites More sharing options...
Russell griffiths Posted January 26 Share Posted January 26 Building a habitable room under that roof without fully replacing it, is probably the silliest thing I’ve heard in a while. Any wind driven rain will just leak through onto the insulation, it will then track down the insulation until it finds a way out onto the plasterboard ceiling, you won’t be able to pinpoint the leak as it won’t appear where it originally came from. 2 Link to comment Share on other sites More sharing options...
Willl Posted January 29 Author Share Posted January 29 How about the idea of using the existing tiles? I do understand that I will have to potentially pay extra for the tiles on the back and side to be carefully removed and sorted between good and worn but worth it if this is good quality old slate yes? Also, to add some warm roof insulation to help keep some head height in this part of the conversion..? Sensible or also silly? Many thanks, Will Link to comment Share on other sites More sharing options...
markc Posted January 29 Share Posted January 29 29 minutes ago, Willl said: How about the idea of using the existing tiles? I do understand that I will have to potentially pay extra for the tiles on the back and side to be carefully removed and sorted between good and worn but worth it if this is good quality old slate yes. Even the very best old welsh slate degrade over time, take the advice above and go with all new, working with old slates or tiles is horrible and only worth it in a conservation or listed building scenario 1 Link to comment Share on other sites More sharing options...
Redbeard Posted January 29 Share Posted January 29 I have seen suggestions that you should allow at least 30% wastage. I was kindly given the slates from a friend's house (OK some which had suffered 'Turnerising' or hessian and bitumen) but even of those that hadn't I reckon I had about 50% wastage. Link to comment Share on other sites More sharing options...
Redbeard Posted January 29 Share Posted January 29 Cross-posted with @markc. Yes, they can be very dirty, but I have been quite happy with 2nd hand slates; it's just all the sorting - not only into good and cr*p but also into thicknesses. I don't think I would have won my 'junior roofer of the year' award, but 'not too bad' would be a fair accolade! 1 Link to comment Share on other sites More sharing options...
Willl Posted January 29 Author Share Posted January 29 What is making me think about using the old slates, is that there doesn't seem to be a new slate or tile that is considered a 'go to' or superior..? Don't want to discard something that is of better quality.. Link to comment Share on other sites More sharing options...
Redbeard Posted January 29 Share Posted January 29 New Welsh would be the 'go to', but at a premium. If I had the choice of fibre-cement or second-hand I'd go for second-hand Welsh, but I'd want to choose them. That's a bit rare nowadays! Link to comment Share on other sites More sharing options...
joe90 Posted January 29 Share Posted January 29 (edited) When I built my build I used Spanish slate and looks very similar to welsh slate and far cheaper. Edited January 29 by joe90 1 Link to comment Share on other sites More sharing options...
Ianto Posted February 5 Share Posted February 5 Having removed and reused slate when I reroofed my old cottage some 30 years ago I would suggest it is just not economic to pay someone to reuse slate either use a modern synthetic slate or go with Spannish slate. You will also need to check the weight of your replacement true Welsh slate was light about 19kg per sq m if I remember correctly you may need to add some reinforcement to the existing structure. Link to comment Share on other sites More sharing options...
Willl Posted February 28 Author Share Posted February 28 Thanks all! Is it possible to tell from the above images if these slates could be reused? Will Link to comment Share on other sites More sharing options...
markc Posted February 28 Share Posted February 28 (edited) 14 minutes ago, Willl said: Thanks all! Is it possible to tell from the above images if these slates could be reused? Will Just about any slate can be reused, but, there will be breakages, lots of sorting, cleaning, swearing and throwing them into a heap … and then wishing you hadn’t bothered. Edited February 28 by markc Link to comment Share on other sites More sharing options...
Mr Punter Posted February 28 Share Posted February 28 19 minutes ago, Willl said: Thanks all! Is it possible to tell from the above images if these slates could be reused? Will I think you may be able to save a few to use on a shed or porch. Your other option is to remove them yourself and carefully stack them. Slates cost less than £2 each. Link to comment Share on other sites More sharing options...
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