Efflo in Flag Path

[tree55 14]

First off thx so much for any help.

I had a contractor install an ariz flag path which I was told was sealed w/ 511 Impregnator. I believe it was because the stone came out MUCH darker then original stone

. After two weeks this gorgeous natural stone is turning almost completely ivory (though not powdery on surface - may be coming up from below sealer). See attached photo.

Q's- How can I:

- tell if this is indeed Efflorecence?

- remove, restore the stone to it's pre sealed state?

- make sure this whitening does not re-appear?

thx again

[PressurePros 249]

That can happen when you apply a solvent based sealer onto masonry that is not completely dry.

When you get the opportunity, fill out your signature line so we all know whom you are.

[CraftonHill 14]

I agree with PressurePros. That is the only time I have seen this happen. How long has it been like this? I know you said it started this 2 weeks after installation but how long has it been since then? I have seen it cure itself out over time. Not always, but have seen it happen. I would be very careful stripping anything off of flagstone. It may be better to let it wear off.

[tree55 14]

The flag went down on 11/29/08 and it started turning white about a week after. Do you all think it's effloresence? And if so will it be able to cure itself out thru the sealer?

[CraftonHill 14]

I do not believe it is efflorescence. I don't think it has been in place long enough, and if it is it had to have started while still at the rock yard. Here is some information about it

-Stopping Efflorescence The link is selling a sealer but I know nothing about it. It just has some info on it that I thought might help you decide if in fact that is what it is. I think it is from moisture in the stone and was sealed while wet. It is hard to tell from a picture. Does it look like crystals???? or does it look more like the seal is discoloring?

[tree55 14]

It does not really look like crystals since the white portions are way to uniform. But may look like the sealer may be discoloring. What can i do about this if this is indeed the case? thx again for all your help

e

[Craig 111]

I also think that moisture was in the rock when it was sealed. It doesn't look like efflor to me. If I were there to do the work I would strip that particular rock, let it dry for a couple of days and then reseal it. Sometimes if you seal a substrate when there is moisture in it it will look chalky.

The other thing that strikes me is that it appears that the chalky substance is only on the one piece of flag. It could have been more wet than the others when it was put down.

If it was efflorescense you could broom it off. Can you do this? Is it powdery? If you put water on it does it temporarily disappear? If not, chances are it is milky from the sealer. It should be stripped and resealed.

There are two types of efflor- 1. Powdery and 2. Calcified. You can do a search on them if you'd like to know more about them.

I think your solution should be pretty simple. Find what will strip the sealer, let it dry and seal.

Edited December 15, 2008 by Craig

[CraftonHill 14]

Craig is exactly right. With Ariz flagstone, be careful what is used to strip it so that it does not take the top layer of the stone off. I would call the person that applied it and have them correct the problem. This should be their issue, not yours.

[tree55 14]

thx craig, to your q's:

- If it was efflorescense you could broom it off. Can you do this? NO

Is it powdery? NO

If you put water on it does it temporarily disappear? IT DARKENS TEMPORARILY BUT EVENTUALLY COMES BACK TO THA CHALKY STATE.

[tree55 14]

thx CraftonHill, are there any sealers you like for flag (i.e Aldon)?

e

[CraftonHill 14]

Actually there are a couple of sealers that are available to homeowners that are good, you just need to reapply them annually. It is not difficult and can be applied with a pump sprayer. One is made by Cabot and is a silicone based masonry waterproofing seal. Another is made by Quikcrete. I do not recommend the high gloss. However, those products would only work if applied to flagstone that has no seal on it. That is one of the reasons I would recommend going back to the person that did it in the first place and making them stand by their work. Stripping the sealer from the flagstone can be tricky and could damage the flagstone if not done correctly. If you as a homeowner decide to take this on yourself it would void any warranty that may apply. If the installer refuses, try contacting the manufacturer of the seal that is currently on the flagstone.

[tree55 14]

thx craftonhill

[PressurePros 249]

I like the Aldon sealers.

[Craig 111]

I also have used the Aldon sealers with good success. Here is a look at a brick restoration job I did a few years back and sealed with Aldon. It still looks great today.

http://www.thegrimescene.com/forums/flatwork-buildings/3200-pics-calcified-efflorescence-restoration.html

I also like everything sold by the Tara Group! (V-Seal etc.)

[tree55 14]

thx craig