Tree Roots, Clay & Ground Movement Issues in Farnham

Why Tree Roots Cause Problems in Farnham Gardens

Tree roots don’t just grow down — they spread horizontally, often reaching 1.5x the height of the tree. In Farnham’s sandy soils, roots travel fast and wide.

Common issues include:

• Patios lifting due to root growth underneath
• Driveway cracking or sinking where roots remove moisture
• Retaining wall failure from root pressure
• Drainage disruption from roots blocking water flow
• Soil shrinkage in clay areas during dry spells

Clay Soil Shrink–Swell Movement (Upper Hale, Heath End)

Where Farnham has clay pockets, moisture changes can cause the soil to expand and contract dramatically. This movement is amplified when nearby trees draw large volumes of water from the soil.

Effects on Landscaping:

• Patios become uneven
• Steps and risers drift out of alignment
• Fencing posts loosen
• Retaining walls lean or crack
• Drainage systems shift out of level

High-Risk Areas for Root & Ground Movement in Farnham

• Lower Bourne — heavy tree coverage, sandy soil
• Frensham — mature trees, sloping ground
• Wrecclesham — soil transitions + tree density
• Rowledge — sandy soil with oak/pine dominance
• Upper Hale / Heath End — clay shrink/swell
• Tilford — wooded, river influence, soft soils
• Crondall / Ewshot — mixed and sometimes disturbed ground

How We Manage Root Zones During Construction

1. Proper Excavation Depth

We dig below the active root layer where necessary, especially for patios near trees.

2. Use of Geo-Grid Reinforcement

On unstable soils, geo-grid strengthens the entire base build-up.

3. Root Barriers

When needed, we install physical root barriers to prevent regrowth beneath patios or driveways.

4. Correct Sub-Base Choice

• Type 1 for firm sandy soils
• Type 3 for clay or waterlogged gardens
• Deep MOT layers where roots have softened the ground

5. Wall Drainage & Reinforcement

Retaining walls receive gravel backfill, weep holes and perforated drainage pipe.

How Tree Roots Interact with Drainage

Roots seek water. In Farnham’s wooded areas, they often target:

• Soakaways
• Old clay drainage pipes
• Poorly wrapped French drains
• Areas where patios trap moisture

Our drainage systems use the correct wraps and aggregates to prevent root intrusion.

When Should You Worry?

Look for these warning signs:

• Patio slabs lifting or cracking
• Driveway dips or bulges
• Soil separating from the house or wall
• Retaining wall leaning forward
• Constant surface pooling near trees

Areas We Cover

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

Need Advice on Tree Root Problems?

If your Farnham garden has tree roots causing patio movement, wall issues or drainage problems, we can help assess and stabilise the site.

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