Thanks Gary, I'll look into it
Gary RK said:
As of this year, There are no residual pesticides currently certified for use in ' blanket spraying' of hard surfaces.
However spot treatment using residuals is still allowed ( there seems to be no official definition on what constitutes 'spot' )
Your local factor should be able to recommend and/ or supply suitable products. However, we use Pro shield which is a mixture with instant knock back glyphosate and residual diflufenican. It works well, giving almost instant response, but is expensive but not if used for spot spraying
Not that i have a need to spray any, but i was under the impression that block paving on a compacted sand bed was considered permeable because a lot of the surface water can seep into all the gaps instead of running off somewhere, although i guess that would only hold true for the first year or so until the gaps got all grubby!
For Spraying; its any surface that is not free draining (paving, block paving, tarmac, concrete etc as opposed to soil, gravel, turf etc)
For Planning purposes, unless its SUDs compliant block paving (ie has drainage slots and uses grit between pavers), its classed as impermeable I believe.
Residuals truly work be creating a chemical pan in the soil that stop most weeds from germinating. Using Residuals en masse on hard surface does very little as there is minimal soil to hold the pesticide and hence can run off into storm water drains, water courses etc.
Thanks for taking the time to reply. I think we might go down the Glyphosate route.