How do you stop weeds growing between pavers?

[#1]

If hand weeding is not possible, spraying path weeder is a safe and effective way to control weeds growing between pavers. Just follow the directions on the label to apply.

Some community members have also had success simply using boiling water, but please take care and use personal protective equipment such as enclosed footwear and gloves.

To minimise gaps between pavers, use paving sand. Sand is the appropriate product as it caters for movement of the pavers. If you were to use a cement-based product, it could crack.

I recommend a product like Dingo 20kg Powerloc Paving Sand which is flexible in nature and a polymer-based product that is resistant to weed growth. You can see Bunnings Workshop community member @TimD use this product in his How to repair an old brick path discussion. - MitchellMc

[ironbark]

I would strongly advise against using any agrochemicals unless it’s absolutely necessary ( as in the scrape and paint on Madeira vine - a really pernicious weed creating enormous environmental issues in Australia). There is no safe agro chemical. I’ve been a horticulturist for 40 years, trained at the RHS and run my own nursery for decades. I believed all the BS during my training and learnt the hard way that glyphosate for instance is very harmful to the body! If your issue is simply weeds in paving, either use boiling water or burn them off with a garden kerosene weed burner. In the garden smothering works well with plastic/cardboard and mulch. ALL AGO-CHEMICALS ARE HARMFUL TO THE ENVIRONMENT! 
The loss of insects (Part of the food chain) over recent years has been drastic. 
Happy gardening, Cheers Jan