Recently Laid Black Limestone Looking Awful!!! - TilersForums.com

[Meander]

We had black limestone laid in May this year. At first it looked great... It had 2 coats of Universeal Ultimate Stone enhancer/sealer but within a couple of weeks looked patchy. The contractor came back and added a 3rd coat. It is supposed to repel most things but everything that touches it seems to leave a mark. Spilt beer or pop will stain and plant pots leave a ring if left for a couple of days. The patio now looks pale grey with patches of white. It looks as if it's been there years not a couple of months.
our contractor went back to the supplier who is not interested. He says that all black limestone will fade over time ( this has been just over 2 months!) it seems as if the sealant has failed but again he will take no responsibility.
our contractor is very good and has a very good reputation but as this is the first black limestone he has out down he is also at a loss.
Any advice/help would be appreciated. He has suggested power washing the whole lot and using a different sealant such as Weiss FT PLUS but we are reluctant to try more expensive products if the same is going to happen. I'm beginning to wish we had left our decking down!!!

 

[Time's Ran Out]

Do a test area - either stone oil or boiled linseed oil.
Don't allow any to stay on the surface after 10 mins wipe off.
Throw cloths away carefully (highly combustible).
Might work and to try will only cost a couple of £.

 

[Meander]

Hi and thanks for your reply. Would I need to remove the sealant that's on there already? There is also a lot of efferecence showing through.

 

[Time's Ran Out]

Just try it on a discreet stone first . If it brings it back to an acceptable look, you'll need to remove sealant and efflorecence and allow to completely dry.
Google your problem and you'll find lots of replies.

 

[SLD]

Efflorence can be removed over time with applying COLD water then soaking up, it is time consuming do a porosity test before you put anything plain spoon of water if it sinks in not enough sealer, also what are you cleaning with flash etc strips sealer needs to be water or ph neutral cleaner I recommend LTP

 

[Meander]

We hVe not cleaned with anything other than hot water and a stuff broom. We had a professional pressure washer man come and do what he could but it made no difference. It seems the sealer has gone milky/patchy do will need removing and then re sealing all over again. We wish we had never spent so much money on the blasted limestone now!

 

[Lee@emctiles]

Best guy to speak to is Jason @ Universeal his number is 07834 686692

 

[Lithofin BOB]

Hi, you say the floor looked patchy , was there a semi sheen to he finish ( shiny patches) if so you may have excess of the products, if so the sealer can whiten due to moisture possibly in the stone or surface rain which will penetrate the excess and can turn cloudy/ white ( dead seal)

If this is the case speak to the supplier Jason he will suggest a suitable stripping agent which you can do a one tile test to deturmine if dead seal also iam sure he will advise on re- application.

Re-seal Only if fully released of all moisture, not just surface dry ( coming to the end of this window)

With the pop and beer , no impregnator holds acidic damage , on a black limestone any acidic attack will turn the stone pale grey

Complete you test, this will tell you where to go

Cheers

 

[IHB]

This: http://www.pavingexpert.com/stonpv05.htm might be worth a read as well.

 

[Lithofin BOB]

This: http://www.pavingexpert.com/stonpv05.htm might be worth a read as well.

Interesting , very difficult to darken contaminated black limestone and ours not really suited for that depth of colour, what they don't state is infact that most contamination is from underlying moisture migrating up underneath any seal and being trapped and then forming the salts possible whitening spalling occurring ( delamination or bloating)

Interesting read cheers

 

[Jelthetiler]

As soon as he mentioned patchy white, I immediately thought of over use of sealer, and the right one too.