it sounds as though this could be either cement staining at the edges of the flags or a manufacturing effect similar to that discussed in another thread.

How wide are these marks and are they exactly parallel with the jointing or do they wary in width? If you have a picture, send it to me via info AT pavingexpert.com and I'll take a look.

The only other comment I should make at this time is that block jointing sand is less than ideal for making what should be a cement mortar. The grain size distribution is not that of a building sand, but then, for a patio, it really shouldn't matter.

Who manufactures the Weathered Bronze Riven flags?

I'd leave the paving for a while longer. Let it have a couple of months of summer and see if it gets any better. If there's no improvement, you could try re-pointing it with a proper mortar in early autumn.

In the meantime, if you do get a photo of the markings, I'd like to see it.

The most common reason for this phenomenion is that the section of jointing immeditely adjacent to the 'staining' is lower than the rest, or it is more permeable and is 'wicking' groundwater from the bedding layer. It's not a 'stain' as such; it's only water and shouldn't have any long term effect, but then again, it shouldn't be as obvious and widespread as it seems to be from the pix you sent.

Is the jointing 'soft' at these wet spots? Try pushing a screwdriver into the jointing. It really shouldn't be able to penetrate, but if it does, it indicates the jointing mix is knackered (technical term) and should be replaced.

However, if the water is being held there because the affected sections are lower than the surrounding paving, there's not a lot you can do. It may well disappear in time, but it really isn't worth losing any sleep over.

See how it goes over the summer.

To be honest I'm a bit fed up as the slabs weren't cheap and we paid a lot of money to have them put down properly. However I can't really call the contractor back as it appears they have done nothing wrong???

Cheers
Richard

the buff riven flags look best poited with a buff mortar, in my opinion. The black mortar is a bit strong and stark, but I'll see if I have any photos in my library. I know I have some pics of buff riven with white (ie, pink) mortar, but I'm not sure what others I have.

With regard to the tray, I wouldn't waste my time, but then, I'm a so-called professional and have been pointing flags since I was 5 years of age (Thanks Dad!). However, somewhere else on this message board, one of the DIY fraternity tried out the pointing tray and reckoned it was a right pile of shi...err, rubbish.

The key to neat pointing is using a stiff mix and being prepared to take your time. "Point in haste, regret at leisure", as a wise flagger once said.

I'll have a look for those pictures later today.

As for the wide joints, is there no chance of re-aligning the flags to even out the joint width? 35mm is the upper limit, really - you can make these exceptionally wide joints look less obvious by making them into a 'feature'. Once you've pointed the joint, press in some small (15-20mm) pebbles or chunks of slate/stone and smooth off the mortar around them.

Good luck for Friday - let us know how you get on.

You need to adjust the joint width to suit.

I'm not familiar with this Tennessee Blue flagstone stuff, but I assume it's pretty similar to our Yorkstone riven paving.

At only an inch thick (25mm), it really does need to be laid on a cement bound bedding, and if concrete is what is normally specified in your area, and concrete is what you agreed, then concrete is what you should get.

Laying on a mortar bed, on top of a crushed stone sub-base is fine as long as the ground beneath (the sub-grade) is suitable, but that's for UK conditions. I believe frost heave is a significant risk in some parts of the USA and therefore I'd be a little more cautious about it's use under those conditions.

If, as you hint, there are significant drainage problems with the sub-grade, then concrete is the safest option to follow. All-in-all, you should get what was oroiginally agreed, and I just hope you have all this in writing!

PS - I know this may sound daft to you, but is this Tennessee Blue Flagstone really blue in colour? Do you have any pictures?

I like a 'landing' at the base of a flight of steps (if you can call two steps a flight!) as I feel it looks more professional and defines the start/end of the structure as well as providing a safe footing for users, so I'd definitely incorporate one. However, I'd make it at least 450mm width, so that it does provide an adequate footing for users. 300mm isn't really wide enough to stand upon safely - my boots are more than 300mm long!

I'm not a big fan of laying brickwork on top of flags, though, because the whole structure becomes dependent on preceding courses of work and, if one section works loose (be it tread or riser),  everything above it is affected. By bedding the risers on a small footing of concrete and then abutting the flag tread, then, if the tread or riser gives way or works loose, it affects only that one step, and not everything else.

Obviously, this isn't as critical on a two step flight, but the principal remains. If you're the client and/or the designer, then you should get what you want, unless there is a sound structural or safety reason to do otherwise.

I don't have the names of any specific dealers but I do know that Pomery Stone shipped a load of granite paving into Belfast recently, and there have been a few loads of the imported Indian sandstone shipped in to Dublin which will probably have found its way north.

Have a look at the Stone Federation Members page as I have a feeling they have some companies based in the North. Alternatively, try the Salvoweb page for details of Salavage and reclamation yards.

Hope that helps - if you do find a good source, let us know their details so I can pass them on to other enquirers.

Are you laying these yourself, Michelle, or bring in a contractor? It can be a right ball-acher trying to get reclaimed flags into a decent random pattern as they often need a good bit of re-dressing to make them fit. Have you considered using a transverse broken bond?

The replacement mortar should be a 5:1 mix (Class II - see Mortars page) and a true mortar, ie, wet but not sloppy and not semi-dry.

Mortar stains - as they are relatively fresh, they might weather away over a month or so, but, if they are quite bad, then brick cleaning acid is the stuff to use.

TEST IT OUT on a discrete corner first, as some acids react adversely with coloured concrete products.

Use a paint brush to paint on the acid, leave it for 10 mins or so, then wash it off. Scrubbing with a wire brush will also help, but be sure to wear goggles and gloves. Assuming the acid doesn't balls up the colouring, you might need to re-apply 3 or 4 times to shift all the staining, but allow the kerbs to dry out each time, so that you can better judge how successful each application has been.

Plasticiser - whatever they have in the BM - FEBmix, PLAmix, Sealomix - they're all approved products and it's not possible to say one is better than the other.

Are you re-pointing them yourself, Dominic, or bringing the contractor back?

Mortar - my mistake: I meant to hit the "4" not the "5" - a class II mortar is 1:4 - sorry for the confusion.
I can't see why the contractor isn't prepared to re-point a 10 m² patio - it would jonly take an hour - why bring in someone else?

Geo-fix - I've seen good things with it and I've seen bad, nay, bloody awful jobs with it. I need a lot of persuading to convince me Geofix is a worthwhile investment on such a small project.

Surely it's only a coincidence that the BM wants to sell you Geofix, at approximately 10 times the price of sand and cement - they wouldn't be looking to earn an extra bob or two, would they?

Contractors in London Village - I know a few, but none that would be prepared to come in over a BH weekend to re-point some other contractor's work. Most of the Contractors in my little black book are really only interested in larger works, 100m² minimum.

You can do this yourself - believe me. Take your time, don't rush it and make sure it's not done during the heat of the day (assuming we get a bit of heat!).

Frankly, I'd insist the contractor comes back and finishes their own work in a professional manner, but it sounds as though you're chasing shadows.

Acid washing is all well and good as a last resort, but it can adversely affect the colours used in concrete pavings, especially the buffs. Have a look at them in, say, September, and then decide if and acid wash is still necessary.

I'll upload your photo's later, if I get the time.

the 10:1 or the semi-dry is fine for those flags - whichever suits you best, as, I assume, there won't be any vehicular traffic. There's not much difference between the two specs I give, anyway: both rely on a small quantity of cement to bind the sand/aggregate together sufficiently without trying to turn it into a rock-solid mass.

A full mortar bed is OTT, but is the usual recommendation from Marshalls and other manufacturers who really ought to know better, but who continue to get away with promoting the practice because it's allegedly easier for DIY'ers.

In our experience, it's actually harder to lay flags onto a wet mix, and there's no need for such a relatively high cement content. Use the semi-dry recipe of a 10:1 mix with minimal water content (if the sand is damp enough, there's no need to add any gauging water at all) and make the bed 35-50mm thick when compacted.

I 'd be interested to hear how you get on with these Timberstones, as previous posters have reported they are a right swine to lay, particularly because of the uneven surface which they say is all but impossible to level with adjacent flags.

Good luck, anyway!

the actual size is Imperial, ie, 24" x 24", rather than the usual metric (which would be 600x600mm)

It's 2 or 3 years since I last worked with these, but I've seen nothing from Stonemarket (who still don't have a website!!) to indicate they have altered this silly practice.

HTH

Good Luck!

there's good Indian Sandstone and there bloody awful shite Indian Sandstone, so it's very important that you check out which type your supplier is offering. Have you seen it, or is it simpy a 'word-of-mouth' offer?

Some is quite crumbly and doesn't cope well with our damp climate. Some is highly laminated and starts to de-laminate (split into layers) a few weeks after completion. But then, some is almost as good as genuine Yorkstone paving. Until you check it out, you can't be sure of what you are buying.

Some of the better, more reputable suppliers will be more than happy to guarantee their stock, so that, god forbid, you were to have a problem, they would arrange for replacements at no cost to yourself, but other suppliers, especially re-sellers (those with no direct experience of paving but selling it as a sideline to, say, a garden centre) may be reluctant to do so.

Top quality riven stone paving is available from UK quarries for about the same price and has the backing of some of the largest paving companies in the country, so you know your purchase will be safe. It is well worth investigating these sources.

The ratio of slab sizes should be determined by your designer, after consideration of the site layout. Will a true random layout be used, or a coursed pattern? A herringbone effect? These factors will determine which ratio is correct for your project, but having a choice of only 3 sized does rather limit the possibilities.

HTH

Anyway, on to the rest of your questions....

Lay the stone on a 10:1 mix of grit sand with cement, as described on the How to Lay page. Start laying in the centre, and make sure the centre is at the highest point, so that water is shed to the edges. I like to establish the centre stone, then use it as a guide to screed out the rest of the bed before placing the outer rings, in sequence.

With the naturral stone, I prefer to butter the flags as they are laid, then point everything up once a ring is complete and had the joints "evened out". I always prefer a dark coloured mortar with stone flags, and from what you describe as the colour, I'd suggest a dark brown or black mortar would look good.

Be careful with the Indian stone, though: there's some right owld shite on the market here in the UK.

If you have any photos of this Rivina stone, I'd love to see them.

To check the stone, try crushing a corner between your thumb and forefinger - if there's any crumbling at all, be very, very wary.

If you don't have a digicam, you can use normal photos and scan them, or I can give you a snail mail address, if you prefer.

Let me know how you get on.

What tools do you have?

Anyway, your best tool, given you're diy, would be a Power Cut-Off Saw or a Nangle Grinder. You must wear goggles and a dust mask when using either of these tools.

Lay your flags so they extend just beyond the line of cut, then mark out your curve with a piece of slate, or chalk. For really accurate curves, you could locate the point of origin and swing an arc from that, but, usually, as long as the curve(s) look sweet to the eye, they'll be fine. Spend a bit of time marking out the curve(s). Stand back and examine the marked line of cut from 5 metres away, from each side, and, if you can, from an upstairs window. Make all your adjustments with the slate/chalk marking - it's much harder to correct misalignment once you've started cutting.

Start at one end of the mark with the saw/nangle grinder, and make sure no-one is stood behind you, in the path of the dust/shrapnel. Lightly score your line of cut with long sweeping moves, then, once you're happy with the score, return over the work and cut to approx half depth of the flags, angling the saw/nangle grinder so that you're undercutting the required section of flag.
A few light taps with a hammer will break off the the unwanted sections.

If you plan to have exposed edges, you may need to saw to full depth and to keep the blade plumb for best finish. If you have a lot of cuts to do in this manner, it's best done with a diamond blade on a power saw, as depth of cut is maintained, unlike an abrasive blade, which wears down as it cuts.

How's that?

However, if you want to send the picture to me, I can upload it to my server for you - post to

Thinking about it, I'm sure there's a pattern book somewhere that calls the above "Tudor" pattern - I reckon folk just call them a fancy name that means something to them, if not to anyone else!

What sizes have you?

Cutting against a curved wall - bugger of a job! For us so-called 'hexperts', we use offset measures or a profile gauge, but it'd take me so long to explain the procedure, it'd be simpler for me to come around and cut the damned things for you! For diy'ers, I reckon the simplest method is to make a template from cardboard, cutting it with a pair of scissors until it fits the gap exactly, then transfer the template to the flag itself and cut it using a power saw or nangle grinder.

Finally, there's a Guinness tax on this site. You can't sup Gunness without buying me a pint!

I'll be over in Wicklow at the end of July, but, hopefully, you'll have it all done by then, Fergus, so there's no point in me bringing my tools with me!

And don't forget the mask and goggles!

Let me know how you get on.

When it comes to laying, though, the semi-dry prevents the flags 'floating' to incorrect levels, and make any remedial work much, much easier. If you want to use mortar, keep it as stiff as possible - a sloppy wet mix is a bloody nightmare. Most contractors prefer to lay on a 'just damp' mix - it's quicker and cleaner than mortar.

The mortar bedding is favoured by DIYers and those with not much experience. The only time it is used on site is on special contracts that have extenuating circumstances, and then a lime-based mortar is used, not a traditional cement mortar.

If so, it suggests the laying method is wrong in some way. Is the contractor tapping them down properly so they bed into the mortar rather than just sit on top of it? Is the bedding thick enough - ideally it should be 35-50mm - and what is it laid on top of? A sub-base or bare earth?

Anyway, back to the flags in question - even if they are bowed, Jason, it shouldn't make them 'rock' when you walk on them. The bedding mortar should take up any difference in the profile of the flags.

Have they been trafficked (by people) in the first 24 hours or so after laying? This can loosen them from a full bed and cause them to rock. Other than that, I can't think of any other reason why they should behave like this.

Just before last Xmas, a regular visitor to the site told us about a supplier he'd found for his Indian Stone.: maybe it'd be worth you having a look....

Pinks Hill Landscape Merchants
Wood Street Village
Guildford
Surrey
GU3 3BP
Tel. 01483 571 1620
Fax. 01483 536816
E-mail  
Website: Pinks Hill

...if you find anyone else, I'd be interested to hear about them.

I was obliged to but a 25kg block of roofing bitumen from them a couple of months ago £15.60 plus VAT. The very same item at my local roofing distributor is 8.20 plus VAT. They are a last resort for me.

It is possible to lay a coursed or a random pattern using those sizes you quote, Pete, it just takes a bit of thinking about.

Send me the details of your supplier and I'll see if I can find a local supplier of the Marshalls stone for you, at a sensible price.

Alternative suppliers...

Kent-Blaxill at Colchester - 01206 216000 - ask for Julian Wood and tell him I referred you. Some luvverly stone, and it's guaranteed.

H.Butterflied in Luton - Their chief buyer told me they are sending 4-6 wagon loads of paving into London Village each day, and they sell to the trade, so it has to be good. 01582 491100 - Ted Holmes is your man to ask.

Silverland Stone at Chertsea - very large stocks and a much tidier operation than Pinks Hill. 01932 569277 - ask for Nigel and again, you can use me as a reference. They also have branches at Codicote and Tring in Herts, Sevenoaks in Kent and Handcross in W.Sussex.

The slate blends well with the Indian stone, but, as with all these projects, it's a matter of taste. Just because I think it looks good, doesn't mean eveyone will think it looks good. A decent supplier will allow you to put the two side-by-side so you can make up your own mind.

I always think light-coloured stone paving looks best with a dark mortar - black or dark brown - whereas some very dark paving, such a black marble or mica-rich granite, looks better with a light coloured mortar. Again it's you that has to live with it, not me, so do a test panel before you commit yourself.

I was chatting with a Landscape Contractor in Ruislip a couple of months back, and he mentioned CED, but I never got the chance to visit their yard and see what sort of set-up they have.

If you peel off the delaminated sections, you may end up with an unven surface and it will take many, many years for the newly exposed surface to develop the worn characteristics of flags seen outdoors. If you want an authentic-looking stone flag floor, then you either put up with what you have and accept it will take time to develop a worn look, or you rip it out, sell it off and buy in 'worn' reclaimed flags from a local supplier.

If you mix polished flags with blocks, then dry sand jointing is fine. Lay the paving just as specified for laying normal flexible block paving, although you could use a 10:1 sand/cement bed if you preferred.

There are other paving websites out there, and some of them illustrate different 'designs', but, apart from the big manufacturers, most feature either photos of existing patios/driveways or bog-standard layouts.

I have a huge collection of design layouts and photographs that I plan to make available online at some point, but it will probably have to wait until I've more free time, possibly in the winter. At last count, I've over 6,200 digital pictures of paving. Sad, eh?

it's not easy to spot if the imported sandstone is 'pukka' or not; it comes down to experience, I suppose, but checking for crumbliness is one simple test, and, from what you say, it's passed. The other simple visual test is to look for de-lamination. This is where the flag is splitting into separate thin layers. This can sometimes be spotted by checking the edges of the flags, and, if there are any obvious 'gaps', then I'd avoid it.

One way of testing the hardness of the stone is to try scratching the surface with a screwdriver. Does the blade penetrate the stone to any significant depth, creating a groove, or is it just a minor scratch on the surface?

25mm really is as thin as you dare go, and, to be honest, I'd be wary with that. There is 30mm stuff on the market for the same sort of price. It must be laid on a full bed, either a semi-dry mix (my preferred method) or a mortar mix. At 25mm thick, these flags aren't strong enough to withstand loading. The Blue Peter method of 5 mortar spots is a definite No-No - too many voids.

30 quid per m² is about the going rate. I can get them for as little as 20 quid up here in t'north, and I know some BMs are knocking them out at 41 quid in that London Village place, so 30 is about right.

With regard to the price you've been quoted for the work. I'd ask for a breakdown of the price. How much for the paving, how much for the edging, how much for the drainage, etc. That will give you a clearer idea of where the money is going. I'd also get at least 3 quotes.

And finally, yes, 150mm is the minimum recommended distance between paving and dpc, whether you have a splash strip or not. You're not going to be prosecuted if it's only, say, 100mm, but it's the sort of thing a surveyor picks up on iof you come to sell the property and it can lead to damp problems in some, but not all, cases.

How's that?

The easiest solution is to lift the few flags that are rocking and stir a trowelfull or two of cement into the bedding before re-seating them, and consolidating again. This will stiffen the bed, and so prevent the flag rocking and so the eventual mortar jointing won't be compromised.

I'd strongly recommend buttering the receiving edges with mortar before re-laying the lifted flags, and then point the joint immediately after consolidation. This will more or less guarantee the previously loose flag is held firmly in place.

Let me know how you get on.