RICS Level 3 Building Survey in CM6 2 Great Dunmow

The geology beneath properties in CM6 2 creates specific structural considerations that our inspectors take into account during every survey. The area sits on London Clay and Boulder Clay deposits, which are known for their shrink-swell potential. When trees draw moisture from the clay in dry summers, the ground contracts and foundations can shift. During wet periods, the clay expands and can cause heave. This cycle puts stress on building foundations, particularly in older properties with shallow footings. Our surveyors have seen numerous cases in Great Dunmow where mature trees, particularly oak and horse chestnut, have caused significant subsidence damage to nearby properties.

Great Dunmow's historic centre contains numerous listed buildings and properties within the Conservation Area, many dating from the medieval period through to Victorian and Edwardian eras. These period properties often feature timber-framed construction, solid brick walls, and traditional lime mortars that require specialist knowledge to assess properly. Our inspectors understand how these older construction methods perform over time and what to look for when evaluating their current condition. We know that timber-framed buildings often have visible signs of historic movement that may have been repaired decades ago, and we can advise whether those repairs remain effective.

The River Chelmer flows through the area, and properties near the river or in low-lying positions face potential flood risk. Surface water flooding can also occur during heavy rainfall, particularly where drainage systems are inadequate. A Level 3 survey identifies these environmental risks and any resulting damage to the property structure. We check floor levels, examine external ground formations, and look for evidence of previous flooding such as watermarks, warped joinery, or damp-related damage to lower floors.

Properties in CM6 2 also reflect the diverse development history of the area. The town expanded significantly during the post-war period, with many semi-detached houses built during the 1950s and 1960s using cavity wall construction that was then relatively new. Later developments from the 1970s onwards brought different construction methods and materials. Our surveyors understand these various construction types and can identify the specific defects that commonly affect each era of building.

• Foundation movement from clay shrink-swell
• Timber decay in period properties
• Flood damage to ground floors
• Roofing wear on traditional tiled roofs
• Damp in solid-walled construction
• Outdated electrical and plumbing systems

Understanding the construction methods used in properties throughout the CM6 2 area helps our surveyors identify potential issues before they become serious problems. Properties built before 1900 in Great Dunmow typically feature traditional timber-framed construction, often with rendered exteriors or brick infill panels. These buildings were constructed with solid walls rather than modern cavity walls, which means they behave differently when exposed to moisture and temperature changes. Our inspectors know how to assess these older wall structures without causing damage and can identify whether historic timber frames remain structurally sound.

The Victorian and Edwardian properties found throughout the town centre were typically built with solid brick walls using lime-based mortars. These mortars are softer than modern cement-based mortars, which allows the walls to breathe but also means they can deteriorate over time if repointed with inappropriate cement mortar. We frequently find that DIY repairs using hard cement mortar have caused moisture to become trapped within walls, leading to damp problems and spalling brickwork. Our survey reports highlight these issues and recommend appropriate repair methods that respect the original construction.

Properties constructed between 1919 and 1980 make up a significant portion of the housing stock in CM6 2. These buildings often feature cavity wall construction, which was introduced to provide better weather resistance and thermal insulation. However, cavity walls from this period may have insulation that has settled or degraded, and the wall ties connecting the outer and inner leaves can corrode over time. Our inspectors examine these elements carefully, particularly in properties where cavity wall insulation has been added, as this can sometimes create new problems if not installed correctly.

Modern properties built since the 1980s generally follow contemporary building regulations, but this does not mean they are problem-free. Extensions, loft conversions, and renovations carried out over the years may not always meet current standards, and our surveyors check for signs of building regulation compliance. We also examine the quality of recent workmanship, as even new build properties can have defects that fall outside the scope of NHBC or similar warranty coverage.

The underlying geology of CM6 2 presents specific structural risks that every buyer should understand before purchasing property in this area. London Clay extends beneath much of the region, and its shrink-swell behaviour creates particular challenges for foundations. When deciduous trees are present near buildings, their root systems draw moisture from the clay during summer months, causing the soil to contract. This movement can foundations to shift, resulting in characteristic diagonal cracking that often appears above windows and doors. Our inspectors have surveyed numerous properties in areas like Stortford Road and Chelmsford Road where mature trees have caused subsidence damage.

The Boulder Clay deposits found in parts of the CM6 2 postcode present similar challenges, though the behaviour can differ slightly depending on the specific composition of the deposit. Properties built on these soils may experience heave as well as subsidence, particularly where ground conditions have been altered by development or where trees have been recently removed. Our survey reports explain these geological factors in plain English and advise on any specific actions buyers should take, such as consulting a structural engineer about underpinning or root barrier installation.

Flood risk is another important consideration for properties in CM6 2, particularly those close to the River Chelmer and its tributaries. While major flooding events are relatively rare, properties in flood zones may have experienced water damage that is not immediately visible during a visual inspection. We look for signs such as stained plaster, warped timber flooring, and salt efflorescence on walls that indicate previous flooding. For properties in higher-risk areas, we recommend obtaining flood risk data from the Environment Agency and may suggest further investigation if we find evidence of damp or water damage at ground floor level.

• Foundation movement from clay soil
• Subsidence from tree root activity
• Heave damage during wet seasons
• River flooding in low-lying areas
• Surface water flooding after heavy rain
• Drainage and soakaway failures

Our experience surveying properties across Great Dunmow and the CM6 2 postcode has revealed several recurring issues that buyers should be aware of. Properties built on the clay soils in this area frequently show signs of subsidence or heave movement, particularly those with large trees nearby. The trees extract moisture from the clay, causing it to contract, and when the trees are removed or during particularly wet seasons, the ground swells again. This cycle can cause visible cracking in walls, particularly around windows and doors. In severe cases, we have seen significant structural movement that required underpinning or other structural repairs costing many thousands of pounds.

Damp problems affect many period properties in the area. Rising damp occurs where damp-proof courses have failed or were never installed, particularly in solid-walled Victorian and Edwardian houses. Penetrating damp results from damaged roof coverings, blocked gutters, or defective pointing allowing water to saturate walls. Condensation is common in older properties that have been modernised with double glazing but lack adequate ventilation. Our inspectors use moisture meters to identify damp problems and determine their likely cause before recommending appropriate remediation.

Timber defects are frequently identified in older properties across CM6 2. Woodworm infestation can affect structural timber that has become damp, while both wet and dry rot can destroy timber elements if left untreated. These problems are particularly common in roof spaces where roof tiles have slipped or in properties with a history of roof leaks. Our surveyors examine all accessible timber elements, including roof trusses, floor joists, and timber frame elements in period properties.

Roofing problems are another common finding in CM6 2 surveys. Traditional clay tiles, while durable, can become brittle over time and may slip or crack, allowing water to penetrate the roof structure. Lead flashing around chimneys and roof windows can deteriorate, causing leaks that may not become apparent until significant damage has occurred. We inspect all accessible roof spaces and provide detailed assessments of the roof's condition along with estimated remaining lifespan and likely repair costs.

• Subsidence cracks from clay soil movement
• Rising damp in solid-walled properties
• Woodworm in roof timbers
• Slipped or damaged clay roof tiles
• Defective guttering and downpipes
• Outdated electrical wiring in period homes