How stop weeds in block paving drive

Mr_Benn

I can see this has been asked over the years,  with varying helpful /non helpful replies.  (the best being dont have block paving ! ) 
We have a block paving drive, about 15 years old, that measures about 2 cars in size. Ive always just used kiln dried sand, but this doesnt stop the weeds, and now some of the gaps between the bricks are about 2" wide. 
Id prefer to brush in a sand that when wetted after, goes hard, as opposed to some of the popular sand sealants, that you wet the drive first but results in the sand sticking to individual bricks, especially older bricks. 
Some of the 'paving sands' seem to really be for big slabs and not for block paving as such. 

https://www.wickes.co.uk/Sika-Paving-Setting-Sand---20kg/p/190843?gad_source=1&gclid=EAIaIQobChMIg8altPH0hwMV3aJQBh3tYjRxEAQYAyABEgJFF_D_BwE&gclsrc=aw.ds
 I realise i may have to come up with a different solution for the bigger gaps. A neighbour has recently used a pour on sealant, but that would cost about £150 for my drive, with no guarantee it will work.
Thanks for any advice.   This is stressing me out more than it should. 

TELLIT01

It's virtually impossible to stop eventual regrowth of weeds in block paving.  Even sealing the drive will only give temporary respite.  Most of the weeds growing in block paving come from seeds being blown in by the wind.  Regular spraying with weedkiller is the only effective way I know of controlling, not eradicating, them.

FreeBear

Mr_Benn said: We have a block paving drive, about 15 years old, that measures about 2 cars in size. Ive always just used kiln dried sand, but this doesnt stop the weeds, and now some of the gaps between the bricks are about 2" wide.

A 2" (or 50mm) gap is pretty impressive. When the blocks were first laid, the gap would have been around 5mm. To open up to 50mm suggests that the edging hasn't been correctly installed on a good solid bed of concrete. I would suggest getting yourself a paver setting tool and nudging the blocks back in to place. Once that is done, rebuild the edging on a thick bed of concrete (typically, 150mm thick) and some decent flaunching behind them.

Filling the existing gaps with a polymeric sand will only be a short term fix if the blocks are allowed to move.

Cheslea2010

Yes, 50mm is definitely too much of a gap for any kind of loose material. Most block paving jobs are now filled with more free draining material such as 1-4mm Joint Aggregate . Kiln Dried Sand is rarely used on new installs now.

MysteryMe

It's the same with weed suppressing membrane. Assists with stopping the growth coming upwards but does nothing to stop dust/soil, seeds and roots blown across from elsewhere or dropped by birds / animals. 

All you can do it keep on top of it either using a weedkiller or one of those thin weeding tools and as others have suggested keep the gap between pavers to a minimum.

Grumpy_chap

A 2" gap indicates something is wrong / moving with the block paving as a whole.  A typical block is 4" x 8" so a gap half the width of the block would suggest someone has been in and taken away half the blocks!

Assuming that the 2" gap is an exaggeration, then I have only ever used kiln dried sand and two strong patio weedkiller applications each year - March and September.  Seems to do the trick.

Bookworm105

there is, as you know, sand on the market which claims to suppress weeds. None on offer imply they are permanent answers.

So, I think the costs of applying weedkiller twice per year is better than the upfront costs of "fancy" sand.
That said, I'd echo the comments that as the gaps are that big, the surface may need relaying anyway. At which point fancy sand would only be a small extra cost and may be the more cost effective option in that case.