Hi,
I have a customer with a stunning split-level limestone terrace / patio approx 125 sq metres laid about 4-5 months ago. He wants it sealed with Resiblock Colour Enhancer but it has a few small patches of efforescence.
I've contacted Resiblock for how best to proceed and they suggest pressure washing first,but in my experience with natural stone,particularly Indian Sandstone,this is purely a temporary fix. It doesn't permanently remove it and it soon returns.
As the enhancer will give it a wet look / black effect I'm thinking this should cover the existing efforescence and wondering if the protective layer that's formed once the Resiblock penetrates the surface will be sufficient to stop any rising to the surface?
I'd be grateful for any opinions or experience with similar issues.
Many thanks.
OK let's look at this logically.
If the patio is only 4/5 months old and it is exhibiting small localised areas of efflorescence then it follows that the efflorescence was probably created when the patio was laid.
Resiblocks solution of pressure washing it just goes to show how naive they are! In fact it's frightening to hear they even said that! Pressure washing efflorescence will exacerbate the problem as you will be feeding it. Efflorescence needs 3 things to manifest itself.
Water
Salts
Route
If you remove any of the three then you stop the efflorescence.
I would in the first instance try removing the efflorescence with a dry sic brush on a rotary machine. If that fails I would try some localised cleaning using Miracle heavy duty acidic cleaner. Then I would deep clean the whole area and then leave it to dry for 48 Hours and then re check to ensure that the efflorescence has not re occurred. If it has just dry brush it and dry vac it off then check again 24 hours later.
Finally Resiblock is probably the last product in the World I would use on limestone. Enhancing sealers need to be penetrating and breathable not topical resin sitting on the surface. Finally if you are going to seal it with an enhancing sealer I would check an enhancer works by wiping it with a damp cloth to see if t darkens? If it does get the clients approval by showing him. Then if all is well I would seal it with penetrating enhancing sealer that is breathable such as Miracle 511 Seal & Enhance
