Most houses, particularly those built some time ago, throw up a few niggles from time to time – damp, draughts, creaky floorboards and so on. While some are pretty harmless, if you've found cold spots on internal walls within your home, you definitely need to pay attention.
"Cold spots are more than just inconvenient; they’re often a sign of underlying problems in your building’s thermal envelope – the barrier that separates your indoor space from the outside environment," explains Ryan Jones, head of testing at Building Energy Experts.
To help you get to the bottom of why cold spots might be appearing and what to do about it, we reached out to the experts – thankfully there are steps you can take to rectify the problem once and for all.
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Ryan joined Building Energy Experts in search of a hands-on sustainability role, where a keen eye for detail and strong problem-solving skills are essential. His Biochemistry degree from the University of Birmingham instilled a passion for using technology to bring about positive change. Ryan is a qualified ATTMA Level 2 Air Tightness and Passivhaus tester, as well as a Category 1 Thermographer and ventilation compliance tester.
What do cold spots on walls mean?
If you have stumbled across a cold patch (or more than one), it is important to understand what caused it.
"A cold patch on a wall means that part of the building is losing heat faster than the rest," picks up Michael Zohouri, founder at Pyramid Eco. "That’s down to poor insulation or thermal bridging, where heat escapes more easily through certain parts of the wall.
"It’s something you see quite often in older properties, especially around windows, on external walls and in corners of rooms," continues Michael. "In some cases it’s just an area where insulation is missing or thinner than it should be."
Ryan Jones reveals a few more causes of cold spots. "Moisture build-up can compromise insulation, structural issues can create thermal bridges (areas where heat transfers more readily) and plumbing issues, such as leaking pipes behind walls or under floors, can introduce cold water into the space."
Michael Zohouri is the founder of Pyramid Eco, bringing over a decade of experience to the company. His expertise spans energy-efficient retrofitting projects, including insulation, solar, and heat pump installations.
How do you find cold spots on walls?
Unless you are happy to walk around your whole house feeling every inch of the walls for cold spots, these can sometimes go undetected. Thankfully, there are other ways of finding them, including looking into the various building surveys available to homeowners.
"You don’t need to rely on guesswork to identify these problem areas," says Ryan Jones. "There are home energy survey methods to identify weaknesses in your building envelope. For example, our thermal imaging survey can detect temperature variations, highlighting cold spots and underlying issues, and our air tightness test measures uncontrolled air leakage, identifying draughts and other energy-wasting gaps in your building."
Are cold spots on walls something to worry about?
Clearly, then, cold spots on walls are an indication that something is not quite right – but what can happen if you simply ignore them?
"Ignoring these issues can lead to drafts and uneven temperatures," warns Ryan Jones. "Cold spots disrupt the overall heating and cooling efficiency, leading to uncomfortable drafts and uneven temperatures. Your HVAC (heating, ventilation and air conditioning) systems have to work overtime to combat heat loss, driving up your energy costs. Cold spots also lead to condensation, creating ideal conditions for mould."
Michael Zohouri agrees that to turn a blind eye to cold spots is a mistake.
"The biggest risk is mould," warns Michael. "Once condensation starts forming regularly on a cold patch, mould spores can take hold quite quickly. It can also mean higher heating bills. If part of the building envelope is losing heat, your heating system has to work harder to keep the room comfortable."
How do you get rid of cold spots on walls?
No doubt once you have discovered any cold spots you will be pretty keen to deal with them before they start causing you too many issues.
"The solution depends on the cause of the problem," picks up Michael Zohouri. "The first thing I would check is insulation. You might find there is no insulation or only a thin layer that’s degraded. Loft insulation, cavity wall insulation or insulated plasterboard can all help raise the surface temperature of the wall.
"Air leaks can also cause cold spots," continues Michael. "Check for any gaps around windows or pipework that could be allowing cold air into the structure. Sealing those gaps can reduce cold patches.
"In some cases your furniture placement in the room could be the problem," adds Michael. "So, if there’s a large wardrobe or a sofa pushed up against an external wall it stops air circulating. That keeps the area colder increases condensation risk. Leaving a small gap behind furniture helps air move around the wall."
Sealing gaps around doors and windows will really help prevent both draughts and cold spots and this roll of self-adhesive tape makes the job really simple. It is easy to cut to size and sticks really firmly to surfaces.
FAQs
How do you check wall insulation?
A well-insulated home is far less likely to suffer from cold spots and subsequent condensation and mould problems, but it can be hard to know what your insulation levels are like, particularly in older properties.
If your home was built after 1920 it is likely to have cavity walls which will hopefully be insulated. You can also get an idea of whether your home has cavity walls by measuring the depth of a wall by a window or door – if it is over 260mm it will probably have a cavity. Be on the lookout for small boreholes in the external brickwork too as these are a good indicator that cavity wall insulation will have been fitted at some point.
Of course, if your home has solid walls things get a little tricky. Unless you want to add internal wall insulation, which means losing some floor space, your other option is to add external wall insulation which is where things can get a little pricey as you will need to reclad the exterior of your home.
DIY testing for insulation is possible using something like this Endoscope Inspection Camera from Amazon. However, for a more accurate picture of your home's insulation, a professional inspection is recommended.
If you have discovered mould has already taken hold due the cold spots in your home, don't panic. In many cases mould removal can be carried out on a DIY basis – the key is to treat it as soon as it appears.
