Gun point mortar problems

[Tony McC]

....should have been sealed before pointing. This is not what I was told or indeed what people seem to suggest on this forum. I understood it was better to leave it to effloresce etc and seal after several months......

With many types of flagstone, there's no need whatsoever for a sealant, but some people like to use one. With many types of flagstone, it's best to allow some time to ensure any problems, such as efflorescence, reflective staining, etc, are not going to happen *before* applying a sealant.

But with some flagstones, and the honed sandstones are classic example, the surface structure is so vulnerable to staining that pre-sealing is, in practical terms, a necessity.

For my money, if a flagstone can't cope with and recover from a bit of staining, then it's no bloody use. If a flagstone needs relatively expensive protective measures to be taken to render it fit for purpose, then I'd be looking around for a more robust alternative, but such is the craze for these honed sandstones that no-one wants to listen to grumpy old cynical Tony - just as they didn't listen when I warned about Travertine.

Does responsibility lie with the supplier who could pre-seal or, at the very least, pre-warn clients about the temperamental nature of this type of flag, or does it ie with the installer, who, as an alleged professional paving contractor, should use their experience to pre-seal and/or pre-warn their customer?

Hard to say, but you can bet your bottom dollar the supplier says it's down to the installer, and the installer blames the supplier!

[Acecross]

I totally agree Tony. The market appears to be very focused on selling additonal products but with a lot of ambiguity around the actual benefits of each - the cost for sealants seems to differ radically - which would be fine if the more expensive ones performed according to their price but from the research I have read this isn't always the case - Dryseal being a case in point. At nearly a grand to seal our stone it had better do the job as intended i.e stop staining but I'm not convinced it would based on tests both in person and on here.

I also agree that if a product needs sealing to perform as intended then it should either be sold pre-sealed or not at all. This would remove any issues.

I'm sure there are people out there who have the experience to avoid these issues - we seem to be in a position where we are having to do the research to make sure we choose appropriate products and materials which is not what I expect when paying good money for a service from a "professional".