The Brew Cabin

Posted: **Thu Aug 14, 2008 10:42 am**

I sealed some indian sandstone approx 8 weeks after laying, using feb aquaseal patio seal.

I did read about efforescence beforehand, but was stuck between a rock and and a hard place as I was getting stains on it from berries. I went ahead as a) I hadn't seen any signs of efforescence , and b) these are not manufactured slabs, so wasn't sure it applied anyway

Anyway, I put two coats on and I'm now getting fairly mild efforescence underneath the surface of the seal. Its not real bad yet, but not sure if its gonna get any worse.

The sealent is the type that only lasts a couple of years anyway, and then needs re-doing, rather than the really durable stuff. Am I right in thinking if it really came to it I could jet-wash the sealer off, and allow the efforescence to wash away naturally? Of will the sealer still hold it in anyway, even if the surface layer is removed?

Any other ideas? I will probably wait and see whether it gets worse, but just trying to see where I stand if it does in the meanwhile.

Cheers

Posted: **Thu Aug 14, 2008 3:32 pm**

I can't see it being eff. What did you lay the flags on? Sometimes they can wick cementitious moisture to the surface via the capillaries in the stone, but, with that sealant in place, I;d have thought evaporation would be drastically reduced.

Posted: **Thu Aug 14, 2008 6:34 pm**

It was laid on a semi dry mix of around 1:6 cement and sharp sand. A little more cement that the recommended 1:10 but thats what the guy that helped me was used to using.

Its coming out in specs of white, and you can see it under the surface of the glaze.

Unless it is a white mark on the top of the glaze, almost the way you'd expect a glaze to go if it had been rubbed - if that makes sense. Is it possible for the seal/glaze itself to get marked? I just assumed it was eff based on what I've read.

As I said it isn't real bad, as long as it doesn't get any worse.

Posted: **Sun Aug 17, 2008 6:01 pm**

White specks usually indicates trapped moisture. It may fade over time, but I've no direct experience with this particular sealant. I'm guessing that it's similar to other 'jack-of-all-trades' sealants, many of which exhibit this very same problem.

The Brew Cabin

Efflorescence sealed in