I recently started the process of cleaning my paver patio because the paver was absolutely covered in moss and weeds. I've been using a pressure washer and blowing out the material alongside cleaning the pavers thoroughly. Over the past two days I'm becoming to appreciate how much effort is takes to collect all the material that the power washer blows out and looking to not do this again in the near future. I'm considering re-filling the joints with polymeric sand, with the hope that this will suppress weeds enough that I won't have to do this again soon. However, I'm wondering how sturdy the polymeric sand is after it sets. Will I be able to powerwash the stones in the future if dirt, moss, or other debris gets on them without blowing out the polymeric sand? If not, what would be the way to clean them without risking blowing out the sand again?
Yes, they can be powerwashed but only if you take the time to do it right and follow the directions to a tee. The joints should be 1/4" wide and as deep as the pavers. Which means you have to remove all the old sand. After applying the jointing sand, compacting is advised and then adding more sand. Extensive cleaning of the surface of the pavers is critical to remove all jointing sand before wetting down the sand. drying and curing time is important too. I just touched on a few of the procedures to use this stuff. It's a lot of work so if you take on the project, take the time to do it right.
You don't want to use a powerwasher set higher than 1600 PSI on the pavers after using the jointing sand.
Polymeric sand will lock together and reduce grass growth but if a dusty environment it will not stop growth. Poly sand locks together but if you hit it with a power washer it will blow it out. I have found products like moss be gone to be more effective then using a simple garden hose to rinse off. We have a 2x extreme issue here Oregon is great for growing moss and we have 10+ horses kicking up dust.