Moisture Control for Conservatories: Simple Steps to Stay Dry
Got a new conservatory or garden room and worried about damp? You’re not alone. Moisture is the biggest enemy of a comfortable extension. The good news is you can stop it before it becomes a nightmare. Below are easy, UK‑focused actions you can take during planning, building, and everyday use.
Ventilation – Let Fresh Air Do the Work
First thing’s first: get air moving. A conservatory without proper airflow turns into a steam room in winter and a swamp in summer. Install roof vents, side louvres, or trickle vents in windows. Open them for at least 15 minutes a day, especially after cooking or showering nearby. Even a small opening cuts condensation dramatically.
Seal the Gaps – Keep Rain Out, Not Air In
Bad seals are the silent damp makers. Use high‑quality flashing around windows, doors, and roof junctions. Apply a silicone‑based sealant that stays flexible for years. Check the seal every spring – cracks appear as the building settles. Re‑seal any gaps before the first heavy rain.
Next, think about the walls. A damp‑proof membrane (DPM) behind the outer cladding stops water from seeping into the timber frame. Combine it with breathable plaster on the inside so any moisture can escape without damaging the structure.
Gutters and downpipes are often overlooked, but they direct water away from the foundation. Clean them regularly and add gutter guards to avoid blockages. A small leak on the roof can drip onto the floor and create hidden mould.
Heating the space helps, too. Even a low‑grade electric heater reduces condensation by raising the air temperature. If you have a floor heating system, set it to a modest 18‑20°C. The extra warmth also makes the room more enjoyable year‑round.
Materials matter. Choose timber that’s been treated for moisture resistance, and avoid solid brick walls if you live in a high‑rain area. Brick veneer with a cavity wall design gives an extra barrier for water.
During construction, ask the builder to perform a “wet test.” They spray a fine mist on the external walls and check for any water leakage inside. It’s a quick way to spot weak spots before the walls are sealed.
Finally, keep an eye on indoor plants. They release moisture into the air, which can add up in a small, sealed space. If you love plants, place them near a vent or use a small dehumidifier.
Moisture control isn’t a one‑off job; it’s a habit. A quick visual check each season, opening vents, and keeping gutters clean will keep your conservatory bright, warm, and dry for years to come.
