Most "damp" problems aren't damp at all — they're condensation. We install Positive Input Ventilation (PIV) units that solve it whole-house in a single visit. Low running costs, no mould, no draught, no nonsense.
Not sure if it's condensation or damp? Take the 60-second condensation check →
If any of these sound familiar, the cause is almost certainly humid air — not water rising up your walls or coming in from outside. Different cause, different fix.
Mould grows where humid air meets a cold surface. Windows, exterior walls behind wardrobes, bathroom ceilings, and the corners of north-facing rooms are the classic spots.
Moisture in your home cools overnight against the coldest surface — your windows. If you're wiping windows down most mornings between October and March, your indoor humidity is far too high.
That damp wardrobe smell, the hallway mustiness, the spare room that always feels stale — humid air sitting still for too long. Often gets worse during winter or after heavy cooking, drying clothes indoors, or long showers.
None of these address the real problem — too much moisture in the air. They're band-aids on a leaking dam.
Only runs while you shower. Your home produces moisture all day — cooking, breathing, drying laundry, kettles, plants. A bathroom fan handles maybe 10% of it.
Lets cold air in (heating bill spike) but the moisture comes back the moment you close them. And nobody wants to sleep with the windows open in January.
Works, but costs £30–£50/month to run, dries one room at a time, and you have to empty the tank daily. Long-term, you'll pay more in electricity than a PIV install.
Hides the symptom for a few months until the mould comes back through. Doesn't change the humidity, doesn't fix the cause, doesn't last.
Manages the visible symptom. The water you wiped is still in your home — it's just pooled in your towel and gone back into the air when the towel dried.
Warm air holds more moisture, so the windows get wetter. Heating without ventilation makes condensation worse, not better. And it's expensive.
PIV is the proven, whole-house treatment for condensation in UK homes. One small unit, fitted in a single visit, runs continuously at very low cost.
A PIV unit sits in your loft (or hallway for flats and bungalows without loft access). A quiet low-energy fan draws clean, filtered air from the loft space and pushes it gently into your home through a single ceiling diffuser fitted at the top of the stairs — the natural high point of the upstairs hallway / landing.
From that one diffuser, fresh air falls down the stairwell and spreads into bedrooms, bathrooms, the landing, and through to the ground floor. The slight positive pressure — your home is now at higher pressure than outside — forces stale, humid air out through every gap, trickle vent and window seal in the building. Air gets replaced every 1–2 hours, 24/7, year-round.
Indoor humidity drops below 60%. Mould can't grow. Windows stop streaming. The musty smell goes. Cooking and shower steam clears in minutes instead of hanging around. One unit, one diffuser, whole house.
PIV is the single most reliable fix for condensation in modern UK housing — recommended by Public Health England, the NHS, and most local authority damp officers.
We install single-point PIV units — one ceiling diffuser at the top of your stairs (the hallway / landing) does the entire upstairs and most of downstairs. Loft-mounted unit above. Single visit. Single tradesman. Two to three hours.
We visit your property, confirm it's condensation (not damp), check loft access, and pick the right diffuser location — usually the upstairs landing ceiling at the top of the stairs. 30–60 minutes. Free, no obligation.
You get a written quote with the unit, install, electrical, and commissioning all included. No hidden extras. Most homes are £900–£1,400 all-in.
One tradesman, 2–3 hours. We mount the PIV unit in the loft, run the duct, fit the diffuser in the hallway / landing ceiling, wire into a fused spur, and commission for your property size. Minimal disruption, no mess.
Set and forget. Annual filter change, otherwise no maintenance. Most units last 15+ years. Within 2–4 weeks you'll see streaming windows stop, mould stop re-growing, and musty smells fade.
Every property is different — loft access, layout, and electrical run all affect price. Below are typical bands. We always survey first so the final quote is fixed.
£900 – £1,400
Loft-mounted unit, ceiling diffuser, ducting, electrical connection, commissioning. Suitable for most UK 2–4 bed houses with loft access.
£1,400 – £1,800
Adds carbon/HEPA filtration (allergen + pollen reduction) and a pre-heater coil so incoming air is warmed in winter. Recommended for asthmatic or hayfever households.
£1,200 – £1,600
Wall- or hallway-mounted PIV (typically Nuaire Drimaster Hallway or equivalent). For flats and bungalows without loft access.
£15 – £25 / year
5–15W continuous draw. Less than a single LED bulb running. Compare to a dehumidifier (£300–£600/year) or constantly opening windows.
All prices include VAT and a 5-year manufacturer warranty on the unit. 1-year workmanship guarantee.
Quick honest comparison of the four options people consider.
For most UK homes with persistent condensation, PIV gives the best long-term value: low upfront, near-zero running cost, whole-house, addresses the cause.
Yes — when condensation is the cause. PIV addresses the root cause (high indoor humidity) rather than the symptom. Within 2–4 weeks of install, most homes see streaming windows stop, mould stops re-growing on cleaned surfaces, and musty smells fade. We only recommend PIV after a free survey confirms condensation is your problem and not penetrating or rising damp.
Around £15–£25 per year on standard tariffs. The fan motor draws 5–15 watts continuously, which is less than a typical LED bulb. Compare that to running a dehumidifier (£300–£600/year) or constantly opening windows in winter (much higher heating bills).
Most installs take 2–3 hours. One tradesman, one visit. We mount the unit in your loft (or hallway for flats), run the duct, fit the diffuser in your hallway or landing ceiling, wire it into a fused spur, commission it for your property size, and you're done.
No. The fan runs at very low speed (you typically can't hear it). Most modern PIV units have built-in temperature sensors that throttle back when loft air is below 10°C, and premium models include a heater coil to pre-warm incoming air. You won't feel a draught — the diffuser disperses air gently across the ceiling.
A dehumidifier removes moisture already in the air (works locally, costs £300–£600/year to run, has to be emptied). A PIV unit prevents the moisture from accumulating in the first place by replacing humid air with fresh dry air whole-house, continuously, for around £15–£25/year. Long-term, PIV is cheaper, quieter, and tackles the entire property — not just one room.
Three quick clues: condensation appears on cold surfaces (windows, exterior walls behind furniture, corners) and is worst in winter — rising damp typically affects the bottom 1m of internal walls year-round, while penetrating damp shows wet patches that follow rain. If unsure, take our free 60-second condensation check or book a free survey — we diagnose the cause before recommending the cure.
2-year manufacturer warranty on the PIV unit itself (industry standard across UK brands). 1-year warranty on installation workmanship from us. The units typically last 15+ years with no maintenance beyond an annual filter change.
We cover Northern England — Manchester, Leeds, Sheffield, Liverpool, Newcastle and surrounding towns. See our full coverage area or call us on 0800 061 4203 to confirm.