Roof Slates

FrankGrimes

Right, made some progress on the slate/tile pricing front.

My total roof area on the extension is around 37 square metres so I'm planning on buying slates/tiles for 43 sq m to give a 15% allowance for breakages/cuts - does that sound right?

Richmond BP quoted 80 cent ex VAT per small clay tile. At 60 tiles per sq m that works out at €48 per sq m ex VAT. I need 43 sq m so thats a total of €2,064 ex VAT (€2,497 inc VAT).

They do large tiles at €2.20 each ex VAT and 11 needed per sq m. Thats €24.20 per sq m, giving me a total of €1040 ex VAT (€1258 inc VAT).

Blue Bangor do not do any tiles in a blue/black colour similar to that of a slate so that rules them out for me - the terracotta would just be out of place in my scenario. Their quote of 65cent per small tile at 60 per sq m works out at €39 per sq m ex VAT. This would give me a total of €1677 ex vat (€2029 inc VAT) if the colour was an option for me.

Chadwicks quoted me at €1.61 per Thrutone Plus man made slate and I'm almost sure this included VAT, though I need to double-check. At 14 slates per sq m (from brochure) thats €22.54 per sq m and I believe thats inc VAT.

We were only looking at clay tiles as a cheaper alternative to our first choice (Thrutone Plus), so if the Thrutone is cheaper overall we'd be very happy.

However, my main question is - for an area of 40 square metres (on a relatively straightforward roof - see images I attached in this thread) would there be significantly higher installation costs for the Thrutone compared to the clay tiles (which are marketed as being as easy to install as concrete tiles)?

As I mentioned, my roof pitch is 33 degrees. Richmond mentioned I would need to increase this by a degree or two to use the small tiles, though the large tiles would be ok as they are interlocking. The Thrutones seem fine for a 33 degree pitch.

The internal ceiling in the extension will follow the pitch of the roof (i.e. plasterboard screwed directly onto the underside of the rafters) - do I need to ventilate the ridge or is this only required for a roof above an uninsulated attic?

Many thanks for your help and hope these prices are a useful guide to others looking about (I had someone call Richmond and Blue Bangor on my behalf so would be hopeful of getting the price down further if going ahead with the deal). By the way, Tegral sent me a very impressive sample and brochure pack when I requested it from their site (www.tegral.com).

rooferPete

Hi Frank,

Now compare the brands and colour of the clay tiles, Blue Bangor is a natural slate and has no relationship to clay tiles.

I can reveal that we did charge more for installing 10" x 6" clay tiles than we did for slates the amount of lathing and setting out for "Rosemary's" is nothing short of a nightmare.

A little history maybe off topic but I like it

The first Building Bye Law / Regulation / Code was introduced by the King after the second great fire of London prohibiting the use of straw or reeds on roofs in the Greater London Area.

Clay tile being available locally was permitted for roofs as they did not catch fire.

.

FrankGrimes

Hi Pete,

You should write a book with all these anecdotes in it. No, really, I reckon it might be an excellent and interesting format for learning this kind of stuff – information on how its currently supposed to be done followed by a background story of how it used to be done to highlight the rationale would be a readable way of getting lots of info across. Anyways, just a thought.

Blue Bangor are an Irish company that do a range of clay tiles in addition to natural slates - http://www.bluebangor.com/tilingproducts.htm . Builderwoman bought her clay tiles from them I think.

My reading of your post is that the Thrutone Plus are not expensive to fit, when compared to tiles (or is it only clay tiles, with concrete tiles being cheaper to fit?). This would mean the Thrutone Plus is cheaper to buy and cheaper to fit, which I have to say sounds too good to be true. Would appreciate confirmation on this one.

I’ve now learned the correct term for my roof is a ‘warm roof’ – i.e. insulation follows the line of the rafters. The Tegral diagrams seem to indicate this required ridge ventilation – is this correct. As for accessories like underlay and underlay holding tray, are these best bought from Tegral or is it a case that they charge a premium for their versions and there are cheaper products that do the same job available?

I just got a call from a Tegral rep to follow up on the brochure and sample pack they sent me – that’s pretty good service.

roofer

hi all
roofer pete seems to have all the bases covered and is clearly the man you should listen to when it comes to roofing matters. i read his notes and learn something new every day.

by posting these notes i hope to share with others my knowledge and experience as a roofing contractor. what i have to say may give you an insight into how roofers think and how they should behave. i believe customer service is nearly as important as the job itself. i also believe clients should be made fully aware of all ther options when it comes to roofing products and service.

getting to the issue of tiles or slates, i can tell you that to fit small clay tiles can be expensive. the workload is much larger. when it comes to interlocking clay tiles be sure that you get a contractor that has done them before.unlike normal tiles the clay tile has a very small tolerance in the spacing of battons.
to get to the point, if the battons are not spaced evenly and correctly the tiles will not interlock properly.the advantage of clay tiles are the aray of accessories that are provided to finish your roof professionally. these accessories are not as common with your standard concrete tile.
now we come to slates. make sure you get a slater to slate your roof, not a tiler.they are two different things,and dont be afraid to ask for references or about previous jobs he has done. after all you are paying for a complete service. any decent contractor will have no problem with this.( others would disagree vigoursly with me). your fitting price for slates will differ to tiles, the jo requires more skill and more time, so it easy to see where your money has gone when it comes to slates.

from my experiences the order of fitting expense would be as follows: concrete tiles.....large clay tiles......slates.....small clay tiles.

i hope this is of use to you
kind regards
roofer:D

FrankGrimes

Thanks for that insight roofer, very helpful.

I thought that Tegral man-made slates are cheaper to fit than natural slates – would it be fair to break it down as follows: the order of fitting expense would be as follows: concrete tiles (cheapest to fit).....large clay tiles......man-made slates……natural slates.....small clay tiles (most expensive to fit).

Its looking more and more like Tegral Thrutone Plus are the ones for me – have you got a rough idea what the going rate is for a price for 560 thrutones over a fairly straightforward 40 square metres? Just looking for a ballpark – is it normally priced per slate or overall job price?

What would you recommend in terms of underlay and ventilation?

rooferPete

Hi Frank,

I'm not completely out of the roofing scene yet and probably never will be, those skills raised my children and were very "kind" to me

Many would be surprised at who some companies in the retail market really are, I know the blue bangor slate company of old, the original title Blue Bangor came from Bangor in Wales the quarry is now known more as Penryhn beside the town of Bangor about 15 miles from Holyhead.

To a real tradesman the order of pricing would be starting at the cheapest :

Concrete roof tiles.

Natural slate (good quality graded)

Man made fibre cement (trutone etc)

Interlocking clay tiles.

Rosemary clay tiles.

Natural slate (of variable quality)

I know the list appears to contradict the material prices but a roof that is in line and square is easier and faster to slate using quality slates, whereas the Fibre Cement has the crampion and two nails to contend with and very little if any forgiveness on a roof that is not "true".

Underlay I like Starex or similar breather membrane.

Ventilation is interesting personally I still say plastic vents are not needed in a natural slate roof mainly because air can circulate under natural slate but the annoying part is why fit plastic with real stone ?

Sorry for going O/T if using a Tegral slate I would use their complete system because the warranty is then complete with one supplier.

Appears I am not far off what "Roofer" has already posted and I can only fully agree with him about the skills profile of the tradesman you choose.

One thing is this for the same roof you posted the photos of ? if it is there are very similar tiles available that will match up with the existing tiles.

A good roof should never be the focal point of the house, it is supposed to blend with all the surrounding finishes presenting a neat finish to the house at first glance.

.

FrankGrimes

rooferPete wrote:

Hi Frank,

One thing is this for the same roof you posted the photos of ? if it is there are very similar tiles available that will match up with the existing tiles.

A good roof should never be the focal point of the house, it is supposed to blend with all the surrounding finishes presenting a neat finish to the house at first glance.

.

Thanks again Pete. The decision I'm making is for tiles/slates for the roof of the single storey extension to be added to the side of what is in PhotoB.jpg above, as detailed in the Front Elevation jpg. I got the tiles to fill in where the chimney was on the existing roof - 15" x 9"s as you suggested.

As concrete tiles only have a 4 year colour guarantee, and I've seen many look untidy while still relatively young, and we also feel the Thrutone Plus will give a tidier finish on the extension roof, which will be very prominent, I think we've almost made our minds up to go with the Thrutone Plus. Next task is sourcing a decent roofer/slater.

Thanks for all the advice.

ninsaga

Hi Rooferpete,
Given that you have some details on these products, could you specify the details exactly what the problems are with them.....what was the hard evidence that you provided?

ninsaga

rooferPete wrote:

Authentic Roof ? forget them, even the Americans who love the slate look alikes are having trouble with them, one Irish supplier who was importing them dropped them when I gave him the hard evidence.

Ballymoon ? looks like a resin bonded slate made from the quarry waste, all efforts at similar have failed to date even though they had certificates.

I have carried out a study on eco star (USA) they are just another type of authentic slate, rubber slates = junk and that's not just my opinion, our friends in the USA tend to be very protective about their home grown products and they are they ones who gave them the thumbs down.

Builderwoman!

FrankGrimes, we used a large clay tile from B Bangor Co. Can't find invoice at mo. We are very happy with them and the look of them. There is also a 30 year colour guarantee on them. I agree concrete tiles can look appaling in no time. Hope you make the correct decision. We know we did for our situation and budget. Our roofers really liked working with the clay tiles too and loved the finish. (It actually got them a lot of attention when doing it because people were calling and asking what they were using!)

newname

Hi Builderwoman,

Can you give me the name and make of the clay tiles you used and how are they looking now a few years later??

Cheers

lazerian

hi,
i was wondering is it possible to slate a roof of less than 18 degrees? ie 16.5 degrees. If not whats the advice?
Thanks

RKQ

No its not! Due to wind blown rain and capillary action this angle is too shallow for slate.

Consider box metal (rear extension), norman sheets, zinc (expensive) or copper.:)