I just moved into a 1950s house with the intention of sprucing up the interior. Upon stripping the wallpaper, I found air vents painted over with multiple layers of paint and cardboard wedged in. I am worried about draughts. Should I leave these vents covered, or should I de-clog them and reseal them properly?
In a house of this age, I would not advise leaving purpose-made wall vents painted over or blocked with cardboard. In most homes, these vents provide background ventilation to habitable rooms. Ventilation is not simply a comfort issue; it is important for maintaining indoor air quality and controlling moisture, and for preventing pollutants and mould growth.
Current ventilation requirements for dwellings are set out in the Building Regulations, with practical guidance in Technical Guidance Document F.
While a 1950s house is not automatically required to be upgraded to modern standards simply because you are redecorating, the principle remains important: habitable rooms need adequate background ventilation, and kitchens, bathrooms and utility rooms generally require dedicated extract ventilation, often by mechanical fan, rather than relying only on opening windows.
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The risk of inadequate ventilation is particularly relevant in older houses. These properties may have limited insulation, colder wall surfaces and more thermal bridging than modern homes. If ventilation is reduced, warm moist air from normal occupation can condense on colder surfaces, increasing the risk of dampness, mould and damage to finishes. Blocking vents may reduce a draught, but it can create a more serious condensation problem.
The practical answer is therefore to have the vents reopened, cleaned out and reinstated properly, rather than covered up. If draughts are the concern, use a proprietary passive vent system, with a properly sleeved wall vent and suitable external and internal covers designed to reduce wind-driven draughts, rather than an improvised cardboard plug.
Wall vents should be properly sized and sleeved through the wall and kept open and unblocked, including during colder weather. If any vent serves an open-flued fire, stove, gas appliance or older boiler, it may be a permanent combustion-air vent and should not be reduced or closed without competent advice.
Because the house dates from the 1950s, there is a second issue to keep in mind before disturbing more finishes. Lead-based paints were widely used in older buildings and can create hazardous dust when old coatings are dry-sanded, aggressively scraped or heated. Separately, asbestos-containing materials may be present in buildings built or refurbished before 2000. Possible locations include textured coatings, floor tiles, panels around boilers, partition boards, flues, old linings and boxed-in areas.
Asbestos is not necessarily dangerous if intact, sealed and left undisturbed. However, if asbestos-containing material is drilled, sanded, broken, removed or otherwise disturbed, it becomes a serious health and safety matter.
Before intrusive refurbishment works, a competent person should assess the likelihood of asbestos being present. In many cases, laboratory testing is the only way to confirm whether a material contains asbestos. If confirmed, removal or remedial work should be carried out by appropriately competent asbestos contractors, with suitable controls and disposal arrangements.
If your decorating work is expanding beyond a simple refresh, this may also be a good time to think about comfort improvements. Stripping wallpaper can reveal loose, uneven or damp-affected plaster, and any moisture or substrate defects should be dealt with before redecoration or dry-lining.
If you are considering internal or external wall insulation, ventilation must be reviewed at the same time, and existing vents should be extended and sleeved through the new build-up where required.
Internal dry lining can improve comfort but is disruptive and reduces room size; external wall insulation is often the more robust solution where feasible. Window upgrades can also make sense, but they should be considered as part of the overall ventilation and insulation strategy, not in isolation.
In short, I would not leave the vents blocked. I would reinstate them properly, check that wet-room extraction is adequate, and confirm whether any vent is needed for an appliance before altering it. Given the age of the house, proceed cautiously around old paint, textured coatings and concealed materials. If the work becomes intrusive, take advice from a competent surveyor or specialist contractor.
Damian King is a Chartered Building Surveyor and a member of the Society of Chartered Surveyors Ireland
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