The Brew Cabin

Posted: **Tue Oct 27, 2020 12:08 pm**

Hi - we are DIYers and have laid a sawn mint sandstone patio on a full mortar bed. We sealed the slabs prior to laying and they're holding up well. But we are unsure what to do about jointing the patio. In the short term, we have used kiln dried sand to fill the quite narrow joints. Is there anything actually wrong with doing this? Would it cause damage to the patio over time?

If there is something wrong with using kiln dried sand then what products would you advise us to use for jointing a patio so prone to staining?! We shied away from a traditional mortar mix because of the potential for staining.

Thanks in advance!

Posted: **Tue Oct 27, 2020 12:38 pm**

The KDS will wash out - that's the prime reason why it isn't used for anything other than short, narrow joints, such as those with block pavers. Once a joint gets to be more than around 5mm in width and/or 450mm in length, there's too much potential for surface water scour to simply wash it all away.

Given the need to avoid staining, and that you're DIY rather than trade, I'd suggest one of the better 2-part resin jointing mortars. Simple to apply, especially in the wet weather; minimal risk of staining as long as the guidance is followed; service lifespan well in excess of 20 years; and immune to powerwashing....it has everything you could want from a jointing product!

See - https://www.pavingexpert.com/jointing13

The Brew Cabin

Jointing options for sawn mint sandstone flags