Block paving gap filler?

[neversay]

I was considering using a sand/cement mix between my driveway block pavings which have lost their 'grout' over time. Is that the way to go or should I be using other products? (Geofix?) (particularly to avoid weeds/moss if possible!)

TIA,

N.

[quelquod]

I think that brushing a sand/cement mix around would be a bad idea as it's almost certain to stain the pavers as it will be hard to brush off the surfaces. If you want to try on a small area remember that you'll need the kiln-dried fine silica sand as the mix will need to be both very fine and bone dry. I don't think that any of the Geofix-type jointing compounds would be successful either because they're rather coarse to brush into the fairly narrow joints to any depth.

I think the only thing likely so succeed is to clean and sand the paving in the usual way and then liberally apply one of the many paving sealants. (Just google for 'block paving sealant'). This will soak into the jointing sand and set quite hard. I've never done this though I know of paving companies who do it. It's supposed to help keep the pavers clean and reduce weed growth. Needs reapplication from time to time. I've no idea what the long-term effect on the appearance of the pavers might be although short-term they seem shiny and water-repellant.

[neversay]

Thanks quelquod. That's great advice.

[Mike88]

You have to use kiln dried sand between block paving joints; otherwise using normal sand will attract moss. The best way to reduce weed growth is to lay weed suppression fabric before laying the foundations for the bricks but obviously that is now too late. Even then you will never stop weed growth with block paving unless the drive is sealed as suggested by the earlier poster.

[sg31]

I agree about using kiln dried sand. Ideally you should apply it to the surface in dry conditions and use a compaction plate to vibrate it into the gaps. That will produce a very tight job.

A sealant is supposed to help reduce moss growth although I've never had much success with it, maybe I haven't used the right one.

[neversay]

Thanks all. I will try the kiln dried sand and sealant route. Having been away for quite a few weeks, all I need now is some dry weather...

[JMN2]

Same as you would repoint a brick wall, you can do the same to a paving, still same sort of gaps there you would fill with regular mortar unless there is a big colour difference.

[Mike88]

Same as you would repoint a brick wall, you can do the same to a paving, still same sort of gaps there you would fill with regular mortar unless there is a big colour difference.

I challenge you to try that! The gap between block paviors is so small you would never get the cement in. The established route is kiln dried sand as mentioned aboe

[Watis]

I think you're talking at cross purposes.

There are paving slabs where it is usual to separate them by half an inch (or a centimetre if you prefer) and fill in the gap with a dry cement mix which sets not too hard by absorbing moisture from the air. The OP refers to this as the 'grout' which has disappeared over time.

And then there's the smaller blocks that are butted up against each other, where fine sand is used to fill whatever gaps there are.

Watis

[neversay]

Thanks. In my case, it's fine cracks between blocks that butt up to one another - so kiln dried sand seems to be the way to go. Perhaps this weekend will be dry enough for me to crack on with it!

[Mike88]

I think you're talking at cross purposes.

There are paving slabs where it is usual to separate them by half an inch (or a centimetre if you prefer) and fill in the gap with a dry cement mix which sets not too hard by absorbing moisture from the air. The OP refers to this as the 'grout' which has disappeared over time.

And then there's the smaller blocks that are butted up against each other, where fine sand is used to fill whatever gaps there are.

Watis

There shouldn't be any confusion as the original post made it clear that he was referring to block paving.