How to clean sealed sandstone pavers?

[AnandDIYER]

Hi there experts!

This is my first post here. I had a company do a sandstone tiling job outdoors. They used the 'wet lay' method to stick sandstones on a compacted roadbase surface using sand/ cement mortar. I thought it is all well and fine, until a few days after they finished the job that I started seeing stains on the tiles. They wouldnt come off with soap, bicarb soda or bleach, including pressure wash. On further reading, I realized the stains are possibly due to the company sealing the tiles when they were still wet (I do remember asking them why they are sealing it only after 4 hours or so after the pressure wash). I am looking for advice to get the ugly stains out. If it includes stripping the sealer for those tiles, I am ok to do that. Appreciate any feedback/ suggestions please. Thanks much for reading! This has been an expensive project and is frustrating to see the tiles like this. Just for reference, they were installed a month ago.

[EricL]

Hi @AnandDIYER 

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about your sandstone pavers.

After reading your description of the early sealing of the pavers. I suspect that this is exactly what happened and that the moisture inside the paver got trapped and has more or less ruined the seal. Technically the paver has to be bone dry before applying any form of seal on top. 

If your pavers have only been recently installed, its therefore still under warranty, I suggest asking your installer to strip the old seal off and re-sealing it properly.

Stripping the old seal can be done two ways, one is by mechanical means and that means running a sander or grinder over the surface of the pavers. The second method is to chemically strip the paver, but in order to do this, the correct stripping agent must be used on the sealer, or it won't work properly. Your installer will know the brand of sealer that was used.

There are some excellent sealers available from the Crommelin Seal Paving range. I recommend visiting your local store and having a look at the sample board so that you can get a better idea of the finishes available.

Here is a handy step-by-step guide: How to seal outdoor pavers.

If you have any other questions we can help with, please let us know.

Eric

[AnandDIYER]

Thanks Eric for your prompt response. I will try the mechanical stripping of the sealant first, as I am a bit wary of adding any more chemicals to the tile. Do you believe the stain (along with the sealant) will come off with a bit of sanding down? Appreciate your feedback. I will be sure to check out the Crommelin range for sealing after the stain has been removed and a couple of days of drying of the tile. Thanks!

[Jason]

Hi @AnandDIYER,

Let me also extend a very warm welcome to the site. 

As Eric mentioned, I would highly recommend you do everything you can to try to get the installer to resolve this situation for you before contemplating any D.I.Y. methods. If you attempt to start your own repairs the installer is unlikely to assist and might suggest your warranty is now void. 

Jason

[EricL]

Hello @AnandDIYER 

I suggest calling your installer to do this activity for you as it requires experience and the proper equipment to do it the right way. Keep in mind that the pavers are still under warranty. Applying any physical changes to them could result in your warranty becoming disqualified.

If you have any other questions we can help with, please let us know.

Eric

[AnandDIYER]

Thanks Eric and Jason for your inputs, appreciate it. Unfortunately, it is one of those situations where the contractor is not willing to take any accountability for this disastrous outcome. I will need to get this done myself, I am afraid. I checked at Bunnings today. The only sealant removers in stock were those intended for silicone. I will try the manual stripping over the next few days and update the results here. Please let me know if there are any other considerations. I look forward to sending some after pics soon.. 

[EricL]

Hello @AnandDIYER 

Sanding the surface of your paver is a serious undertaking and its quite easy to damage the surface. I recommend getting a quote from a professional paver sealing service. If you have it done by a professional service, it will have a warranty on it, and you won't have to buy any specialized equipment. Plus, they will have the experience and knowledge on how to do it properly.

Manual sanding will produce swirls and marks on the surface of your paver creating more repair issues. In this particular situation, I propose getting it repaired by a professional.

If you need further assistance, please let me know.

Eric