weeds in flagstones

beattiesman

the flagstones in my front garden have weeds growing in the cracks what is the best thing to fill these cracks in with thanks

ArbitraryRandom

Really you've got two choices and which one is 'best' depends on how bad the cracks are and how much you care about doing a 'proper' job.  

1. Pull the weeds and use a paving tool or strong knife you don't care about to dig out the roots. Use a stiff yard brush to fill the cracks with dry grout and wait for rain. 

2. Clean out the weeds using a paving tool, then widen the cracks as needed to ensure a clean fill (if there's a lot then you might want to clear out all of the old grout). Regrout your patio. https://www.pavingexpert.com/patio_rejoint_01  

twopenny

When you say cracks do you mean the slabs are butted up to each other or is there a distinct gap between them where sand and cement once was?

There are different ways to deal as AB describes. Are you agile and active in which case you can really have a go at them - or mobility impaired in which case something immediate that will need repeating?

beattiesman

twopenny there is a distint gap between them.i am quite agile and active so willing to have a go just need to know what is best to fill them in with  

twopenny

Not being agest - but it is sort of relevant :-)
Ok  bigger gaps is weirdly better.
There's a sharp L shaped tool that you can scrape the weeds out with as AB said. I do that or crush te stems and spray with weed killer.

Mine have been filled with what looks like cement with tiny stones in and a finger or sponge used to give a curved shape like a little gulley for water run off. My gaps are about 1cm wide.
If smaller than that the recommendation on here is sharp sand or builders sand. Spread over the gaps and brush in. I haven't tried that but plan to do my ancient block pavers.

ArbitraryRandom

beattiesman said: just need to know what is best to fill them in with  

Dry grout (also called brush in grout) is a pre mix of sand and cement. It means you can put it in dry then when it rains it sets. For small cracks it's less fiddly than making small amounts of wet grout. 

For larger cracks you need to be sure you wet your patio and pack it in well or it'll settle/crumble but it's good for small cracks as you can just brush it in and it'll be set in a few days. There's a ton of products available so just go to your preferred DIY supplier and see what they've got. It'll say on the pack the minimum depth and that it's for external use. 


If it's a bigger job and you're going to redo the lot then the pre-mix stuff is expensive and a bit hit and miss for larger gaps. What I'd recommend then is a basic mix of four parts sand to one part cement made up with water so it's workable but not too runny (the traditional way of doing it). Lots of videos on Youtube if you've not worked with cement before so you can 'see' how thick it's supposed to be.

But in that case you really do need to dig out the roots and properly clean out/widen the gaps between the stones so you get a good fill. 

twopenny

That sounds good AB. I haven't heard of that. Perfect for my old and creaky block paving. The guys at the builders merchants hide when they see me coming I'm sure    
Old lady wanting one small bag, 2 blocks etc.

My backs not sure it thanks you though. Now I want my blocks neat and tidy....after the massive bramble removal from the badger run.

You explain things very precisely and clearly. So glad you joined the team    

FreeBear

ArbitraryRandom said: If it's a bigger job and you're going to redo the lot then the pre-mix stuff is expensive and a bit hit and miss for larger gaps.

Another alternative is polymeric sand - Brush it in to the gaps, then give it a light spray of water a couple of times.

Alfrescodave

The problem with digging out a weed is ensuring that all roots are completely removed otherwise the weed will return. My preference is using a systemic weedkiller and then pull up the weed.

The term weed in this context is a generic word to describe a plant that is growing in a place where it is not wanted. 

ispookie666

Remove the weed, pressure wash, and use either Sika setting sand or Sika All weather fix depending on the gap between the flags or crack size. 
You need to use a spray-on protector. I have used Everest trade(Polyurethane) for my block paved patio and Everbuild 405 for the Indian sandstone and concrete flags.  I am a bit disappointed with the Everbuild 405(Acrylic) and might go with a compatible one from Everest Trade when I need to redo this.  

Slinky

We had our block drive cleaned, resanded and sealed. Sealing was a complete waste of money and the same issues occured a few months later. We cleaned and resanded it again before putting it up for sale which helped improve the look enormously.  They don't stay looking lovely for long.