reclaimed slates

keru

I am costing our new build at the moment and on the subject of slates.
Has anyone any experience of reclaimed slates? I have found some not too far from me. They're valentia slates, have been on a roof for over 150 years and look in good condition.
I have been warned against using reclaimed slates for the increased labour cost in putting them up. Possibly redrilling holes ect... Is it a very specialist job or could I tidy them myself after being shown how to?
Also was warned against old slates retaining water which could cause condensation in under roof and also lead to cracking in cold weather. Is it true?
If I went to inspect them on the roof they are on now what should I look for?
How can I assess them for porosity or other defects?
How can I arrange for their transport? Where can I get crates?
Any true roof expert in Kerry?
Any advice greatly appreciated!

Timmyboy

I have some limited experience of using reclaimed slates.

First of all, you really should do an actual inspection of the slates, ideally looking at them one by one to see that they are in good and reasonable condition.

I believe that I've got Valentia slates on my house and they are extra thick between 8mm to 10mm thick rather than say the 5mm or so of other slates and they have a rather major irregularity to them that gives them "character" I suppose. They would be at least 70 years of age.

I'm fairly sure that you could tidy them yourself but you are best not to unless you know exactly how they are to be arranged and placed on the roof. Best to do any "tidying" as you say when you are fitting them onto the roof on the day of the actual slating and also to ensure that the new slate battens are arranged to suit the existing hole lines on the slates rather than making new holes in a different place.

If the slates are already looking solid and holding their own after 150 years then I'd say that they will last another 150 years without much bother. Try to store the slates carefuly on side edge, near to vertical but with just enough slope in between to allow rain to drain downward (beneath have a few clean 2" x 4" lengths of timber to take the weight of the slates so that they are not sitting in mud and picking up soil staining.

Rub a nail over the surface and see how much flaking that you get. If there is anything other than top layer surface delamination then you are probably OK. Note that around the existing holes that there may be a large amoutn of other delamination but this is typical due to stress cracking at the holes.

To arrange transport, do it carefully in the back of a van with a few layes of old carpet on the ground beneath them and with timber placed between groups to prevent slates knocking off each other and chipping themselves during the drive (on difficult Kerry roads ).

Crates I wouldn't bother with if the distance is reasonable but you will need to take care using some timber and/or old carpet or heavy cardboard separation to try to avoid breakage.

Hope that helps but do probably seek professional advice from your slater as sure I'm just a professional amateur working in that big open air assylum they call the building industry of Ireland. :rolleyes: