Driveway Advice
How do I stop weeds growing in block paving?
Weeds usually grow into block-paving joints from seeds and organic debris at the surface; they rarely grow up through a correctly constructed driveway. Marshalls recommends regular brushing, removing established weeds and replacing any jointing sand pulled out during cleaning. There is no permanently weed-free paving surface, so prevention depends on keeping debris out of the joints and keeping those joints properly filled rather than relying on a one-off treatment.
Most weeds arrive from above
Marshalls' maintenance guidance says weeds normally colonise sand-filled joints or germinate in accumulated dirt. It is very rare for them to grow through the full pavement construction. This distinction matters because a homeowner may otherwise pay for unnecessary excavation when the actual problem is surface debris, open joints or neglected edges.
Start with removal and regular brushing
Pull or scrape out visible weeds and remove loose leaves, soil and other organic material. Marshalls recommends regular brushing because it disturbs small seedlings before they establish. Work carefully around the joints; aggressive tools can displace sand or damage the paving edges.
Re-sand any joints disturbed during cleaning
Weed roots can lift jointing sand when they are removed. Marshalls says that lost material should be replaced as soon as the surface is clean because partially filled or empty joints are detrimental to pavement performance. Use the jointing material specified for the installed system; permeable block paving may require a different aggregate from conventional kiln-dried sand.
Use treatment products only as directed
If a weed-control product is needed, identify the paving material and follow both the paving and treatment manufacturers' current instructions. Marshalls notes that chemical methods should not be used on clay products in its block-paving cleaning guide. Protect planting, watercourses and drainage routes, and never mix chemicals or improvise a concentration.
Look for a recurring source of debris or joint loss
Fast regrowth can point to overhanging vegetation, soil washing across the driveway, repeated pressure-washing, poor edge restraint or chronically empty joints. Fixing the cause and restoring the joints is more useful than repeatedly treating the visible leaves. Movement, depressions or persistent joint loss justify an inspection of the paving construction.
A practical weed-control routine
- Sweep away leaves, soil and loose debris before it builds up in the joints.
- Pull or scrape out established weeds without damaging the blocks.
- Allow the surface to dry and inspect the depth of every disturbed joint.
- Replace lost jointing material with the type specified for the paving system.
- Repeat light brushing and investigate any area that repeatedly loses sand or moves.
| What you see | Likely issue | Useful response |
|---|---|---|
| Small seedlings in dusty joints | Airborne seed and accumulated debris | Brush regularly and keep the surface clean |
| Sand comes out with weed roots | Jointing material disturbed during removal | Clean, dry and re-sand with the specified material |
| Growth returns along the boundary | Soil or vegetation entering from the edge | Clear the edge and check the restraint |
| Joints empty after pressure washing | Cleaning method removed support material | Reduce pressure and restore the joints |
| Weeds appear with sinking or movement | Possible construction or drainage issue | Inspect the affected layers before cosmetic treatment |
Frequently asked questions
- Do weeds grow through the sub-base?
- Usually not. Marshalls says weeds normally grow into sand-filled joints from seeds and debris at the surface, and that growth through the full pavement structure is very rare when construction is correct.
- Will sealing stop block-paving weeds permanently?
- No. There is no permanently weed-free paving surface. A compatible sealer may change joint behaviour, but debris, edge growth and damaged joints still require maintenance.
- Should I replace sand after pulling weeds?
- Yes where material has been removed. Marshalls says partially filled or empty joints are detrimental to performance, so restore them with the correct material after cleaning and drying.
- Can I use weed killer on clay block paving?
- Do not assume so. Marshalls' cleaning guide says chemical weed-removal methods should not be used on clay products. Check the exact paving and product instructions first.
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