The roof is a 90 year old slate roof. The nails have nail sickness and a couple of slates have already come off. Apart from the nail sickness, there's nothing wrong with the slate tiles themselves. Therefore, is it viable to refit the whole roof using the old slate tiles whilst using new nails to secure them, or should we replace the old slates with new tiles , in order to make it fully watertight and up to standard?
*Many thanks for both of your replies. I did wonder if it would be more cost effective to recycle the old slate tiles, and not too concerned if new tiles look different. It's cost whilst being water tight and up to standard that are the main concerns. The 90 year old slate tiles are quite sturdy and don't break ( I tried to snap one in half and it remained solid and not brittle at all.) Take the point about how long you could guarantee they would stay in this condition though after 90 years.
With solid 90 year old slates, is recycling them still a viable option in terms of cost and maintaining a water tight roof?
Are you a tradesperson and able to answer this question?
you can refit the existing slates using new copper tacs this would not be a great issue, but you will lose a few of them on removal generally about 1/3. depending on the size of the original slates you may get new ones or reclaimed if you want them to look like the rest of the roof,
Without looking at the roof in question it impossible to say what condition they are in but welsh slate which was the only slate available back then was & still is the best & longest lasting slate in the world, it will easily last 1-200 years
the biggest problem with buying reclaimed is you do get a lot of crap from the reclaimed yards so can end up needing to buy twice as many as you require it also depends on the size of the slate as a lot of sizes are only available as reclaimed,
Standard size for new slate is 250/500
10/20 inch in old money
A good quality slate will set you back £2-2.60 +
While the slates may look ok you will lose at least 1/3 on removal.
If it was me I would do one side using the existing slates and the other side with a new grade 1 premium slate probably Spanish which is a nice slate
Providing it is under felted & slated correctly it will remain water tight the main reason for failure of a slate roof is slipped tiles due to nail fatique, the way it was constructed original would have been using lime mortar as your under felt catching and water seepage that got under your slates but as lime Mortar need moisture to thrive and your roof leak very little this will be long gone the nails will have rusted hence the failure of the roof, old materials were made to last and treated with care new materials are not as we now live in a disposable society
good luck Alex
Yes it's possible but not feasible as old slate tends to be brittle so alot damage when removing so new have to be bought to replace the broken and the extra time it takes in carefully removing just isn't productive also you've got no way of knowing how long the old slate has life left init after all its been doing its job for 90 years already open to all elements and how do you guarantee that? ide just advise on a replacement new slate or tile
