5 common issues you might see on your survey - and why they may not be a problem

If you've ever bought a house, you'll know that one of the steps in the buying process is getting a survey. Reading your survey can provoke anxiety but it's important to remember that many problems detected are ordinary and not a great cause for worry.

This isn't to say a building survey is unimportant or that you should ignore the results. On the contrary, it is vital to get one and to know what you're looking at in case there is a genuine problem. A study by the Royal Institute of Chartered Surveyors revealed that 4 in 5 homeowners bought a property without having a survey, resulting in an average bill of £5,750 for unexpected repair jobs.

But many myths have arisen about survey findings, so we're here to dispel some misconceptions. Let's look at the most common issues, how bad they could be, what costs you might incur and what you can do about them. 

Japanese knotweed

An invasive plant species, Japanese knotweed thrives in the UK as native insect species don't eat it. Deep-rooted and stubborn, this fast-growing, pervasive plant can be near-impossible to get rid of. It will re-emerge after herbicides have eradicated surface growth, and often you need to completely and extensively excavate the area with specialist disposal of it being very expensive.

As the plant can damage boundary walls, drains, driveways, paths and paving, its presence should not be ignored by potential buyers. It leads to structural issues like leaky roofs and faulty drains, and can devalue a property to the point of making it unsellable.

That said, because Japanese knotweed may be beneath the surface, and because surveyors aren’t experts in the matter, they normally include it in their assessment regardless of what they see to protect themselves in the event the plant isn’t spotted! So don’t panic unless they’ve seen knotweed, or they’ve heard of nearby outbreaks. 

If this is highlighted, make sure you verify the weed's presence. A seller is legally obliged to tell you if they know their land is affected so try asking the current owners first. Failing that, ask neighbours if they have heard of outbreaks nearby.

Where Japanese knotweed is a confirmed issue, an expert opinion and specialist help is needed. In some circumstances, mortgage providers will refuse to lend against properties with knotweed. The cost of removing even a small patch can be £2,000-£3,000, and sometimes up to £12,000 for a 10m² area.

Rising damp

Damp is perhaps the most common house survey problem. It can be caused by poor ventilation and condensation inside a property, by water penetrating from the outside via roof leaks or by rising damp. 

It was once thought that rising damp rose up through the walls from the ground, but the former chairman of the Royal Institute of Chartered Surveyors has dispelled this as a myth. It’s now assumed to be caused by condensation due to poor ventilation.

While damp has health implications and can cause issues like dry rot and wet rot, don't panic just because you read it on a survey. Damp varies greatly in severity, and it can simply be caused by people’s habits or because the property hasn’t been lived in for a while. Opening windows occasionally, using the trickle vents and keeping the heating on at a low temperature can help, so it can be worth asking if the seller does any of this.

A little bit of damp is not a serious problem. So before reaching any decision, take note of how widespread the problem is. If it's only a small patch, and it’s caught early, getting rid of it could be a straightforward process - DIY measures might be enough. 

It’s much more costly to fix the damage than the cause of damp. If it’s left unchecked, extensive measures - like the rebuilding of walls - may be needed, and this can cost thousands of pounds. 

Your survey will list the cause, and your surveyor can tell you what steps are required to remove it. If you still have concerns, booking a damp survey inspection by a damp specialist will give you more meaningful information.

Structural movement

Unexplained cracks in walls and split plaster around windows and doors can all be signs of structural movement. However, cracks in older properties can be pretty innocuous and not necessarily indicative of deeper structural problems. 

Older properties were built to have a little movement in them, and this is why the original lime plaster on walls was more flexible. If cracks are more than 5mm wide, and you can fit a pound coin edge into them, they’re usually deemed serious. But you don’t need to be concerned by hairline cracks. 

If a survey picks up on structural movement, it is essential to know how badly the building is affected. Leaky drains, tree roots and clay soil shrinkage (see below) can cause all sorts of issues, including structural movement. In the worst cases, underpinning the building's foundations may be required - a time-consuming and very expensive job. It can be hard to secure buildings insurance and therefore even a mortgage on an affected property too.

But as with other survey issues, take time to discover the exact nature of the problem and don't jump to the worst conclusion straightaway. Expert investigation and reliable estimates for remedial work will allow you to make an informed decision about the property and are reasonable grounds for renegotiating the asking price.

Clay soil

Related to the issue above, houses built on clay soil are prone to subsidence. London is notorious for clay soil subsidence difficulties, especially as homes built before 1965 often have shallow foundations. 

According to buildingconservation.com, clay materials are found in many areas of the UK but are much more common in the south and east of England. Clay type soil covers roughly 45% of England and Wales according to LandIS (Land Information System), so it’s not surprising that there’s a number of homes built upon it.

When it becomes dry, clay soil is likely to shrink. Trees planted close by can exacerbate this issue by sucking moisture out of the ground. Escaping water can be a problem too. The soil might be washed away by damaged water pipes and drains. If the ground beneath a house sinks, it causes the entire property to shift on its foundations which results in structural damage. While a property's age or nearby trees can cause subsidence, soil issues are the principal problem. 

However, clay soil is not necessarily a concern, provided your home has the right foundations. 

With land for building in high demand, construction companies developed techniques to lay foundations on clay soil that won't subside, and regulations have evolved to ensure building standards are high enough to prevent future problems. So more modern homes are less likely to experience subsidence issues. As ever, investigate the issue and discuss it with your surveyor, so you have a clear understanding of the problem.

Asbestos

Seeing asbestos on your survey can send chills up the spine and call to mind horror stories of death and terrible illness amongst those who were exposed to it. In the past, asbestos was a frequently used material because of its natural fire resistance. It can be found in homes built or refurbished before the year 1999, but importantly not after. 

But if asbestos is in a property you're thinking of buying, it's important to put its presence into perspective. Asbestos-related deaths principally occurred because long-term exposure led to workers inhaling its dangerous fibres.

Whether asbestos in your home is a safety risk or not depends upon its location and whether you are likely to come into contact with it. So, for example, you're unlikely to come into contact with asbestos in a shed roof, so its presence there need not be a major issue. 

However, asbestos was used in many household areas, not just garages and sheds. In pre-2000 homes, it may be found in the roof, ceilings, doors, eaves, insulation panels, flues or old storage heaters. It was also used in partition walls and as packing between floors.

Having to remove it can bring unexpected costs and requires professional tradesmen, so if you suspect asbestos could be widespread in a property, consider booking a specialist survey. According to Checkatrade, an asbestos survey for a 2-3 bedroom house costs between £150 and £350. Be aware an in-depth check may necessitate some damage to the property and cause minor repair issues.