Sealants for imported sawn indian sandstone - Best sealant for this specific job

Patio flagstones (slabs), concrete flags, stone flags including yorkstone and imported flagstones.
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biskit
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Joined: Mon Nov 28, 2011 10:20 am
Location: Wokingham, UK

Post: # 70823Post biskit

Hi,

Newbie here so Hi and pleased to be part of this. Also really looking forward to getting your advice on this specific problem we have :)

Previously did all our paving ourselves but with concrete flags, etc. as that's what we could afford the last time! Now have 2 kids and no time so we've just had 85 sq m of sawn Indian sandstone (teakwood) installed and I'm keen to get a sealer on it as soon as is reasonable, taking advantage of the relatively warm dry weather we've been having recently. Fingers crossed.

Junior member of the contractors team turned up late on Saturday afternoon (pointing having only been finished on fri afternoon/sat morn) expecting to be able to clean all the boot and wheel barrow marks off with a brush before applying a "sealant" which he couldn't explain to me what it was (apparently they have for block paving and 1 for patios (as in all patios not just natural stone which set my alarm bells ringing)). Thanks to this great site we have a little education so can at least ask fairly intelligent questions. Needless to say thanks to sterling advice here we sent him away with several questions about efflorescence, impregnators, dryness and how precisely he expected to clean it to our satisfaction in 30 minutes and with only a brush before we were even willing to consider £500 for what he had hoped was an hours worth of brushing and some spraying!!!!

Having gone through that conversation I suspect that thanks to support from this site and some reasonable competence in technical matters we could probably do a better quality job (I'm a scientist, hubby is an engineer). Intend to try to shift off contractors muddy boot marks with 50% solution of water and bleach - had a go with a brush over the weekend but that clearly wasn't cutting it!

So this site recommends coverguard and weiss stainprotect profi as both good for sandstone. Do others have experience of using these products on sawn (smooth) sandstone, especially the teakwood variety? Can you give any tips? Any idea on the best location to obtain these products from (Weiss has a list on their website but "coverguard" is proving difficult to track down as a more generic word so less easily identifiable via Google) - either delivered or within a reasonable distance of Berkshire/Wiltshire?

The 85sqm are made up of a 65sqm patio and two paths - 1 garden path and the other at the side of the house and we're in Berkshire in the UK so not too rainy. Joints are pointed. One part of the path is near a fruiting shrub but other than that simply looking to protect the patio from the usual food, cooking, drink, etc. stains oh and children's scooter wheels of course! So ideally an impregnator that helps with both oil and water based stains. No need for stabilisation just looking to try to keep it looking as good as it can for as long as possible. Also prefer the natural look just as it is no the more neutral the product the better.

Any tips or thoughts on the risks of applying at this damper time of year compared with waiting until it turns warm (ish) and dry (ish) again - spring onwards i.e. the risk of permanent winter stain damage to the stone due to leaves/birds/etc. (obviously this was reason contractor was using to "sell" their immediate need to seal). Is it just milkyness due to damp in the stone I need to worry about - if I understand advice correctly this should be less of a problem with an impregnator anyway as it soaks in rather than sits on surface and is breathable anyway so can let any residual mositure out. Or is there anything else?

Thanks again for all your advice.

RAPressureWashing
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Post: # 70827Post RAPressureWashing

Hi,

For me and most on here it is to late in the year to seal, to damp & to cold. As far as the contractor saying we have one for block paving and one for patios, I wouldn't let them touch it as it is most prob, going to be a cheap acrylic sealer that will fail. Let the paving over winter, then in the spring do a full clean and seal. You are not that far away from us so if you want a cost to do the work next year, feel free to email me.

Roger
Roger Oakley BDA(Europe)Member 2006
R&A Pressure Washing Services Ltd
info@rapressurewashing.co.uk
www.rapressurewashing.co.uk

London Stone Paving
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Post: # 70830Post London Stone Paving

I would agree with Roger. It's not a good time to seal at the moment. Even though the patio might look like its dry it could be holding moisture in the stone which is not visible. anyhow you will need to give it a really good clean prior to any sealing, which will involve using water.

I dont want to sound like the grim reaper but teakwood is quite a soft stone which means it's quite porous. It will soak up a lot of sealant, dont expect to get any more than 6 or 7m2 per litre (2 coats).

Dont go for a cheap sealant, they dont last long. Go for either lithofin stain stop or Drytreat. Drytreat is the best one but its also expensive. The reason its more expensive is because it contains a lot more sealant and less carrier than other sealants on the market. Drytreat will also offer a 15 year guarantee if it is installed by a drytreat installer. Dont be scared off by this option, the local drytreat rep will train your sealing contractor on the job free of charge.

If you want any further details PM me

lutonlagerlout
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Post: # 70841Post lutonlagerlout

"(I'm a scientist, hubby is an engineer)"
really, the wrong 2 people to try and BS with jargon :)

I have used lithofin MN stainstop with some success but it needs redoing every 2-3 years
roger and steve are to sealants what jobs and gates are to 'puters , and it is waaaaay too late to seal

teakwood is a soft stone but soft is relative

try and keep as much detritus off the paving over the winter, patio pots and planters are your enemy here

the boot and barrow marks should come off with water and a brush ,unless of course they are cement :O

regards LLL
"what,you want paying today??"

YOUR TEXT GOES HERE

London Stone Paving
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Post: # 70851Post London Stone Paving

lutonlagerlout wrote:I have used lithofin MN stainstop with some success but it needs redoing every 2-3 years
roger and steve are to sealants what jobs and gates are to 'puters , and it is waaaaay too late to seal

teakwood is a soft stone but soft is relative

try and keep as much detritus off the paving over the winter, patio pots and planters are your enemy here

the boot and barrow marks should come off with water and a brush ,unless of course they are cement :O

regards LLL
Its an interesting one. Although the softer ones do get dirtier more quickly they also clean up quite quickly as well.

the sawn raj green and the sawn kandla grey are both rock hard stones which dont mark as easy but seem to pick up some really stubborn stains which are difficult to shift.

Lithofin do a product called outdoor cleaner which will shift any birdshit or vegetation marks.

LLL, your spot on about plant pots, they can make a right mess of natural stone. In theory you should be able to use acid on teakwood but tread very very carfeully and take some professional advice if you ever need to use acid

Bilabonic
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Joined: Sun Sep 04, 2005 3:51 pm
Location: Wales

Post: # 70852Post Bilabonic

I used some H202 35% industrial grade on my Fawn stone, did water it down and sprayed onto the stone.

Milk i heard is good for sealant...Not sure where i read that though......lol

biskit
Posts: 3
Joined: Mon Nov 28, 2011 10:20 am
Location: Wokingham, UK

Post: # 70864Post biskit

All,

Thanks so much for the good advice - all very much appreciated. Clearly whilst being able to follow what is being said and being a pretty quick study we’re lacking proper training or better still experience so all sage words and real world tips most appreciated.

LSP – thanks we’re aware of the porosity – have been planning at the 4m2/L end of expectations. Quite happy to languish proper care, attention, periodic maintenance and funding for the right stuff. Although for Lithofin MN stain stop at £24 per litre and needing 2 coats might start to get into the realms of pushing it ....... After paying what could have been a well kitted out small car we want to keep it in tip top condition and enjoy it for as long as possible. Plus it’s definitely holding water, not only evaporating from the mortar but given we’ve seen the paving in high summer and prior to ordering we “test watered� a sample to check we were happy with both the summer and winter look the colour change is quite noticeable! Thanks for the cleaner tips – main site seems to suggest bleach/water but given test clean described below by the time we get to spring might need something a bit stronger!

lutonlargerlout – quite right blinding 2 PhDs with science is never a sensible plan although having a sensible discussion with someone who clearly knows their trade is always a very pleasant experience and one which we’d be happy to pay a premium to work with that person. Didn’t expect to get any decent work out of him considering he turned up in pressed shirt, decent jeans and proper shoes so how he expected to clean the mess up prior to sealing without raising a sweat I don’t know. OK so my PhD’s in chemistry (which I don’t tend to mention because I don’t want to scare people!) so whilst I don’t expect someone to be able to tell me what’s going on at the atomic level of my paving I do expect them to have read the label of the product they’re planning to apply and be able to answer some reasonable questions – like what do you mean it’s dry - you only finished pointing it this morning and it’s porous stone and rained last night so it can’t be properly dry..... Perfect tips re: leaves, pots, etc. as the thing I was trying to understand was whether these stains were likely to be worse if the paving was left unsealed through the winter and therefore whether I’d gain anything by trying to treat it with an impregnator. My theory (no practical experience though) was that if the impregnator could be got into the stone far enough then it would still be able to breath and thus dry out as it would do otherwise come the spring and yet provide a degree of protection to the surface. With regard to what the staining is – I hope mostly mud but the barrow was going backwards and forwards between mixing area and laying area (main patio is in the middle of the front and rear paths and they laid the rear path and did some other landscaping last rather than first – personally I would have started at the back and worked towards the rear). There are also a few very black marks which to me look like carbon (ash) but I can’t explain where they have come from. I gave a couple of slabs a scrub earlier just with water and a small, stiff floor brush. It shifted some of the muck but nowhere near all – suspect there are quite a few splodges of pointing mix (although they did do it quite carefully initially putting it in with a mastic type gun) so I’m hoping there won’t be too much cement in the tracks or too many cement containing splodges. A few marks are liveable but tyre tracks and boot prints would be annoying!

Bilabionic – thanks good tip and if I’ve got any peroxide left over I can water it down a bit more and do my hair to match the paving ;-)

I guess the only question I have left in my mind or will do come the spring is the thorny issue of pressure washing. If one were to wash the slabs, gently, avoiding as much as possible the joints what are the pros and cons over using a more chemical approach to cleaning? Presumably Lithofin would have tested their outdoor cleaner and MN stainstop for chemical compatibility anyway so after giving the stone a thorough wash off post outdoor cleaner use I don’t have to worry about any tiny residues being left deep in the stone causing reactions.

Has anyone any experience with either Coverguard or Weiss StainProtect Profi - I ask because on the mainsite Lithofin NM StainStop is listed as good but giving a slightly damp look and I'm keen to go for something as neutral as possible.

Thanks again - especially for taking the trouble to read my long messages!

lutonlagerlout
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Post: # 70867Post lutonlagerlout

lithofin MN stainstop (catchy name from those germans eh?) is totally invisible within a day of application
I think the jollop that LSP mentioned may be of the same calibre but i have no experience of that
anything called waterseal avoid like the plague(you know the one)
unless we get a very indian summer with 3-4 dry and frost free days it would be unwise to seal before april
the reason for keeping pots, leaves,bikes etc off the surface is that once there these items tend to stay there for 3-4 months and cause localised staining
I have seen it and its hard to shift
easier to keep it swept
cheers LLL :)
"what,you want paying today??"

YOUR TEXT GOES HERE

London Stone Paving
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Post: # 70910Post London Stone Paving

biskit wrote:Lithofin would have tested their outdoor cleaner and MN stainstop for chemical compatibility anyway so after giving the stone a thorough wash off post outdoor cleaner use I don’t have to worry about any tiny residues being left deep in the stone causing reactions.

Has anyone any experience with either Coverguard or Weiss StainProtect Profi - I ask because on the mainsite Lithofin NM StainStop is listed as good but giving a slightly damp look and I'm keen to go for something as neutral as possible.
I've sealed loads of times after using outdoor cleaner and have never had any problems.

I have never heard off the sealants you mention, so could not cement on them. Lithofin does not give a damp look unless used on really dense stones, where it cannot absorb properly and just sits on the surface. Teakwood is not particuarly dense so you should not have this problem.

Why not to a few tests on off cuts using different sealants so you can see for yourself if there is any colour change

London Stone Paving
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Post: # 70912Post London Stone Paving

London Stone Paving wrote:
biskit wrote:Lithofin would have tested their outdoor cleaner and MN stainstop for chemical compatibility anyway so after giving the stone a thorough wash off post outdoor cleaner use I don’t have to worry about any tiny residues being left deep in the stone causing reactions.

Has anyone any experience with either Coverguard or Weiss StainProtect Profi - I ask because on the mainsite Lithofin NM StainStop is listed as good but giving a slightly damp look and I'm keen to go for something as neutral as possible.
I've sealed loads of times after using outdoor cleaner and have never had any problems.

I have never heard off the sealants you mention, so could not comment on them. Lithofin does not give a damp look unless used on really dense stones, where it cannot absorb properly and just sits on the surface. Teakwood is not particuarly dense so you should not have this problem.

Why not do a few tests on off cuts using different sealants so you can see for yourself if there is any colour change

biskit
Posts: 3
Joined: Mon Nov 28, 2011 10:20 am
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Post: # 70918Post biskit

Thanks - makes perfect sense that it would have a wetter look on a denser stone and also that teakwood is v porous. Useful info. I got the names of the other products from one of the pages on the main site: http://www.pavingexpert.com/sealant_02.htm So the fact that you haven't heard of them makes a whole lot of sense of the sparse to non existent Google hits which prompted this disucssion thread ;-)

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