Weeds - how to stop/prevent/slown down on my patio and drive?

We had our drive re-done so that it is now one solid slab with a pattern to make it look like flags (of cement, concrete or whatever they use) so that it had no gaps for weeds to grow through. Before that we just had to try and dig the weeds out from the gaps. You could also try filling the gaps with cement after digging out the weeds.