Weeds in Block Paving and Re-sanding Joints

How weeds get established

Jointing sand slowly washes and wears away. Rain carries soil and organic matter into the gaps, and wind drops seeds into them. Moss often arrives first, creating a damp mat that weeds then root into.

Joints along the edges, around manhole covers and beside walls usually go first, because they collect most debris and see the least foot or tyre traffic.

Clearing joints properly

Weeds need lifting with their roots, not just cutting at the surface. Moss and soil in the joints are scraped out, and the drive is then cleaned to wash away loose debris. The aim is to get back to clean joints that can take fresh sand.

Tools that gouge or chip block edges are avoided. On delicate or older blocks, hand tools are slower but kinder.

Why re-sanding matters

Fresh kiln-dried sand brushed into clean, dry joints locks the blocks together and leaves little space or organic matter for weeds. It also helps stop blocks moving under car tyres.

The sand needs dry weather and dry blocks to flow properly into the joints, so timing depends on the forecast. Joints may need topping up after the sand settles.

Jointing compounds and sealants

Some people choose polymeric jointing products or a sealer to bind the sand. These can reduce weeds further but must suit the paving and be applied correctly. We explain general options in our driveway sealing guide; sealing is not a service we offer.

Whatever is used, joints still collect debris over time and benefit from sweeping.

When weeds point to a bigger problem

If blocks are sinking, rocking or spreading, the bed beneath may have failed, often because of poor sub-base or water getting in. Weeds then grow in the wider gaps. Cleaning will make this obvious but cannot correct it.

In that case a paving contractor can lift and relay the affected area. We will mention movement we notice so you can decide.

Keeping joints weed-free

Sweep regularly with a stiff brush, especially in autumn. Pull new weeds while they are small. Keep soil from borders off the drive with a clean edge. Top up joint sand when you notice it dropping.

Our moss killer vs cleaning guide explains where treatments fit.

How long re-sanding lasts

Kiln-dried sand gradually settles, washes and wears, especially on drives used daily. Most owners find joints need a light top-up every so often rather than a full re-sand. The interval depends on traffic, rainfall and how well the joints were filled originally.

Brushing a little sand into joints that look low is an easy job you can do yourself between professional cleans.

Edges and manhole covers

The edges of a block drive and the blocks around manhole and inspection covers are where joints fail first. Cut blocks leave wider gaps, and edging restraints can shift. These areas often need the most attention during clearing and re-sanding.

If edge blocks are loose or missing, re-sanding alone will not hold them; a paving contractor may need to reset the edging.

Patios and paths too

The same principles apply to block paved paths and patios. Joints lose sand, fill with soil and sprout weeds. Clearing and re-sanding patios and paths at the same time as the drive gives a consistent finish around the house.

Our patio cleaning page covers slabs and natural stone.

Ants and lifted sand

Ants often nest beneath block paving and push fine sand up through the joints, leaving little heaps on the surface. Over time this empties joints and lets weeds in. Re-sanding after a clean refills those gaps, though ants may return.

Some stabilising jointing products resist ants better than loose sand. A paving specialist can advise if ants are a persistent problem on your drive.

Booking joint clearing and re-sanding

Joint clearing and re-sanding is part of how we approach block drives on our block paving cleaning service, and it can be included in a wider driveway clean. Send photos for a free quote.