Stopping weeds coming through paving

[veedee]

Paving stones on balcony have weeds coming through.

Need advice on effectively dealing with this.

After lifting the paving stones, I notices that they were laid on some sort of foam

Can I just

1. Sweep up the organic matter from the foam

2. Lay a weed membrane over the foam

3. Relay the paving stones

4. Fill gaps with kiln dried sand

5. Clean organic matter from the gravel stone and relay

or do I need to do something else?

 

[Deluks]

Weed membrane wont do anything here. They are growing in the dirt on between the slabs. Even if you took that out there will still be trapped moisture under the slabs that will be enough for some weeds to survive on.
By all means clean it up. But in the future, regular weeding or spraying will keep them in check.

Not sure how sand would work here when the slabs are effectively suspended on those bearers, I suspect they have been designed that way to allow for drainage.

 

[veedee]

Weed membrane wont do anything here. They are growing in the dirt on between the slabs. Even if you took that out there will still be trapped moisture under the slabs that will be enough for some weeds to survive on.
By all means clean it up. But in the future, regular weeding or spraying will keep them in check.

Not sure how sand would work here when the slabs are effectively suspended on those bearers, I suspect they have been designed that way to allow for drainage.

Thank you. Yes, it must be for drainage.

I am assuming that I should still go ahead with filling the paving slab gaps with kiln dried sand?

Would laying the the gravel stones on a membrane be worthwhile or again useless?

 

[Deluks]

What was in the gaps before? Sand is great medium for roots to get into.

What's under the gravel now?
Weeds quite happily grow between the stones on top of membrane.
You'd only really use it if you've got soil underneath everything. On a balcony I don't see the point.

Although if you neglected it for a while I suppose the membrane would stop big roots from growing under and along. Wouldn't guarantee it though.

 

[veedee]

What was in the gaps before?

Honestly it looks like nothing was there.. Although, i find it hard to believe that it was installed this way..

Or are paving slabs sometimes laid with nothing between the gaps for drainage?

Sand is great medium for roots to get into.

What would be ideal filling material? Sand and cement mix?

Or again, is it best to leave it for drainage purposes?

What's under the gravel now?

The same foam material under the paving slabs

Weeds quite happily grow between the stones on top of membrane.
You'd only really use it if you've got soil underneath everything. On a balcony I don't see the point.

Although if you neglected it for a while I suppose the membrane would stop big roots from growing under and along. Wouldn't guarantee it though.

Okay, sounds like the membrane serves no purpose. Thanks.

 

[veedee]

Can anyone address the best filling material. Or should the gap be left open for drainage purposes?

 

[veedee]

Can anyone address the best filling material. Or should the gap be left open for drainage purposes?

 

[Deluks]

Where does the water go when it rains heavily?
If this is a balcony, presumably there is some sort of gutter/drainage channel taking water away so it doesn't pool?

 

[StephenOak]

Where does the water go when it rains heavily?
If this is a balcony, presumably there is some sort of gutter/drainage channel taking water away so it doesn't pool?

Assuming that there is some drainage, then if the gaps between the slabs are filled with sand, when it rains the sand will be washed out and down the drain.

 

[noseall]

Paving stones on balcony have weeds coming through.

Need advice on effectively dealing with this.

After lifting the paving stones, I notices that they were laid on some sort of foam

Can I just

1. Sweep up the organic matter from the foam

2. Lay a weed membrane over the foam

3. Relay the paving stones

4. Fill gaps with kiln dried sand

5. Clean organic matter from the gravel stone and relay

or do I need to do something else?

You either fill it solid i.e. with sand cement or polymer pointing and take the risk water may pond everywhere or you leave it as it is and go out there and keep it weed free every other week. The UK is a green and pleasant land and will totally ignore your pleading for it not to grow weeds. You have a Garden of Eden there and the weeds know it.

 

[veedee]

Where does the water go when it rains heavily?
If this is a balcony, presumably there is some sort of gutter/drainage channel taking water away so it doesn't pool?

Yes, there's a gutter/drainage channel

Assuming that there is some drainage, then if the gaps between the slabs are filled with sand, when it rains the sand will be washed out and down the drain.

So sand is pointless. Thanks.

You either fill it solid i.e. with sand cement or polymer pointing and take the risk water may pond everywhere or you leave it as it is and go out there and keep it weed free every other week. The UK is a green and pleasant land and will totally ignore your pleading for it not to grow weeds. You have a Garden of Eden there and the weeds know it.

Brilliant. Thank you

Even filled with sand/cement. I'm confident that water will drain around the perimeter as this area is made up of just gravel stones. The gravel stones are laid directly on top of the same suspended bearers and foam the paving stones are, so they should effectively drain.

However, if i were to leave the gaps unfilled and chose to weed instead, would spraying salt water be an effective weed killer?