Garden Drainage & Groundworks in Farnham

Why Farnham Gardens Experience Drainage Issues

Farnham has a varied geological makeup that affects how water moves through the ground and how we design each scheme:

• Sandy subsoils in Lower Bourne & Wrecclesham – free-draining but unstable under repeated loading if not properly compacted.
• Clay lenses in Upper Hale & Heath End – hold water and cause persistent boggy patches where surface water has nowhere to go.
• Silty soils in Frensham & Tilford – slower drainage but good compaction when treated correctly.
• Tree-heavy areas (Rowledge, Crondall) – roots compete for moisture and disturb ground levels over time, sometimes affecting paving and retaining wall stability.

Common Signs of Poor Drainage

• Standing water for more than 24–48 hours after rain.
• Soft, spongy lawn areas that never fully dry.
• Moss and algae growth on patios and paths.
• Water running towards the house or garage.
• Subsidence around paving, steps or retaining walls.
• Visible soil erosion or washout in heavy rain.

French Drains

A French drain is one of the most effective solutions for intercepting and redirecting surface and subsurface water before it reaches problem areas.

How We Install French Drains

• Trench excavated along the problem area or desired intercept line.
• Geotextile membrane lining the base and sides of the trench.
• Free-draining shingle/backfill to create a permeable zone.
• Perforated pipe installed at a controlled gradient.
• Membrane wrap and final cover layer (gravel, soil or turf as appropriate).

Best For:

• Waterlogged lawn edges and borders.
• Patios with standing water along one edge.
• Base of slopes (common in The Bourne & Frensham).

Soakaways

A soakaway helps store and disperse rainwater into the soil, keeping it away from buildings and hard surfaces. They are often paired with driveway channel drains or patio falls.

Typical Farnham Applications

• Large patios draining into soft ground.
• Driveway runoff management where direct discharge is not suitable.
• Properties without mains surface drainage connections.

Note: In areas with heavier clay, soakaways may need to be combined with land drains, regrading or alternative systems for reliable performance.

Channel Drains & Threshold Details

Channel drains are ideal where patio or driveway levels approach the house or thresholds and are a key part of modern SUDS-compliant design.

• Installed along door thresholds or at the base of slopes.
• Connected to soakaways or other safe discharge points.
• Essential around bi-fold and sliding door areas to prevent splashback and pooling.

Regrading & Level Management

Many Farnham gardens have natural slopes. We often reshape levels to:

• Encourage water to flow away from buildings and key seating areas.
• Create usable terrace levels for patios and lawns.
• Remove dips that naturally collect water.
• Improve overall lawn usability and mowing lines.

Retaining Wall Drainage

Any retaining wall requires proper back drainage, especially in Farnham’s mixed soil regions where water can accumulate behind structures.

• Weep holes through the wall face where appropriate.
• Gravel backfill to form a free-draining zone.
• Perforated drainage pipe at the base, laid to falls.
• Geotextile separation layers to prevent fines clogging the stone.

For more on structural design, see our retaining walls & level changes guide.

Drainage for Patios & Hard Landscaping

We design patios with the correct falls so rainwater naturally moves toward a drain or appropriate soft ground. This is especially important for porcelain and other low-absorption surfaces.

• Falls of around 1:60 to 1:80 depending on surface material and texture.
• Porcelain laid on full mortar beds with priming slurry for stability.
• Sub-base reinforcement and depth adjustments on weaker or made-up ground.
• Integration with channel drains, French drains or soakaways as needed.

Areas We Cover

Farnham · Wrecclesham · Lower Bourne · Rowledge · Upper Hale · Heath End · Runfold · Frensham · Tilford · Crondall · Ewshot · Boundstone

Experiencing Drainage Problems in Farnham?

We can assess your property, map levels and soil conditions, and design a long-lasting drainage solution tailored to Farnham's ground conditions and your planned landscaping. If you are also budgeting for wider works, our Farnham landscaping costs guide gives a useful overview of typical investment levels.

Request a Drainage Assessment

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