"To effectively resolve a damp problem, it’s essential to address the issue at the source rather than only treating the symptoms. Therefore, landlords should be extra vigilant for well-meaning repairs by residents"
- Nicholas Donnithorne - Peter Cox
The UK has some of the oldest housing stock in Europe, so some properties may struggle to cope in the face of the unrelenting wet weather we’ve seen so far this year. Heavy rainfall can exacerbate existing property issues, often leading to penetrating damp.
Luckily, there are some simple steps landlords can take to ensure properties can cope with extended periods of wet weather. It is important to review your property regularly. By conducting regular inspections and addressing tenants’ queries promptly, you can catch small issues before they have the chance to spiral into expensive problems.
Knowing the causes of damp and how to spot it
Penetrating damp occurs when water seeps through walls or external defects, and is often made worse by driving rain and strong winds.
Rising damp is less common and is due to moisture travelling up through the brickwork or masonry of a property. It will only occur on ground floor elevations, and is more likely to occur in older buildings where damp proof courses may have deteriorated or are missing altogether. Older buildings are also more likely to have solid walls, which increases the risk of both rising and penetrating damp.
Visual signs to look out for when you inspect your property include cracked plaster, peeling wallpaper and staining or discolouration on walls. The presence of black mould is another clear indicator of damp, as is a persistent musty smell with no obvious source, so it’s worth investigating any suspicious smells.
If damp appears to come and go, such as dark patches on walls after rain which fade in dry weather, this can indicate penetrating damp or hygroscopic salts drawing moisture from the air. Both suggest a longer-term issue.
If damp is present, don’t ignore it. When we’ve polled householders in the past, an alarming number admitted to trying to deal with damp by simply painting or papering over it - a short-term fix that allows damage to spread unseen. To effectively resolve a damp problem, it’s essential to address the issue at the source rather than only treating the symptoms. Therefore, landlords should be extra vigilant for well-meaning repairs by residents.
Over time, serious damp issues can lead to rotting skirting boards, decaying timbers, and mould growth on leather and other household materials. So, if in doubt, seek expert advice.
Steps to prevent damp
Damp problems can start from the outside of your property, where small defects allow water to penetrate over time. As previously mentioned, the best thing to do is conduct regular checks of your property to identify signs of deterioration before water has a chance to penetrate. You can do this as part of landlord inspections, or encourage and educate tenants to check themselves.
Start by taking a look at your property’s exterior. Repair any cracks, leaks, or gaps in walls, roofs and pipework. Inspect the roof and interior loft spaces for signs of moisture, examine external walls for crumbling or decay, check the seals around windows, doors and appliances remain watertight. Loose or damaged pointing and rendering should also be repaired, as this can allow wind-driven rain to penetrate masonry.
The application of a water repellent cream to external masonry is a really good way to help prevent rain penetration, provided the mortar is in good condition. Additionally, it has been scientifically proven to reduce heat loss in single skin masonry by improving thermal resistance, thereby saving energy.
Guttering and drainage systems also deserve attention. Renters may well not check the guttering regularly, despite its crucial role in protecting against water damage. In recent years, intense short-period rain events have become far more common.
Rainwater goods designed for longer duration, more gentle rainfall may no longer have sufficient capacity and, if partly blocked by debris, will not be able to cope. The same is true of the drainage system when partly blocked by decaying leaves or fibrous tree roots that have gained entry to the pipes. This is particularly true where old systems carry sewage and rainwater, rather than being separated.
As with gutters, the size and number of drainage pipes were designed for longer rain events, meaning that, during intense bursts of rain, manholes can overflow rapidly and flooding can occur. This is a good reason to have drain surveys undertaken.
Finally, hard-standing areas such as parking spaces or patios may provide additional drainage challenges. Runoff must be adequately planned for; water may enter nearby buildings. This is also becoming an issue where step-free thresholds are retrofitted to aid accessibility.
What to do if you notice a problem
If damp is detected and you’re unsure of the root cause, it’s best to consider a professional survey from a qualified surveyor.
A damp survey will identify the source and extent of the issue, allowing for tailored solutions depending on the problem found. This can vary from remedial damp proof courses for rising damp or improvements to ventilation for condensation and mould. In some cases, repairs to existing building defects and improved maintenance may be sufficient.
