Chimney upstairs & downstairs flue have rain mushroom-plug w/side holes.
Neighbour had chimney repointed by known good builder reported no chimney problems up top.
House is cavity, no rendering, loft recently checked ok & insulated.
Downstairs flue is vented.
Bottom vent via gas fire which sees very light usage.
Upstairs flue - no vent.
Front & Rear fireplace sealed by plasterboard in 1950.
Upstairs flue vents to underfloor.
Specifically to a 4-inch wide "duct" between wall & joist leading to hall landing, so ventilation is via meagre floorboard to skirting gap.
Problems.
1. Lift landing floorboards, breathing flue downdraft gives you a vicious cold if more than a few minutes. No obvious smell, most likely black mould in chimney, fungal strep etc.
2. Downdraft from cold chimney would just vent it thro a fireplace vent.
Ceilings fine. Wood fine. No wallpaper staining. Redecoration up to fireplace panel showed no mould, plaster ok.
81yr relative will not agree to a vent in the fireplace panel (or its removal). Indeed I wonder if such a vent would just let in the cold downdraft & bugs?
Solution?
1. Run downstairs fire more frequently, vs monthly for 5hrs in winter.
2. Fit soffit-vent in the ceiling under the landing, which "ducts" straight to the upstairs flue.
3. Forced ventilation, at least to drop humidity level down, then vent.
Thus providing some direct ventilation from a permanently warm source.
All joists are rough sawn (just after WWII) so I am wary of any damp anywhere, upstairs cinderblock walls AND ceilings sit on joists.
Ironically I wonder if *summer* is worst, because in winter all the heating will naturally heat the underfloor area so aiding an updraft (although limited by meagre ventilation).
Q - Advice?
Neighbour had chimney repointed by known good builder reported no chimney problems up top.
House is cavity, no rendering, loft recently checked ok & insulated.
Downstairs flue is vented.
Bottom vent via gas fire which sees very light usage.
Upstairs flue - no vent.
Front & Rear fireplace sealed by plasterboard in 1950.
Upstairs flue vents to underfloor.
Specifically to a 4-inch wide "duct" between wall & joist leading to hall landing, so ventilation is via meagre floorboard to skirting gap.
Problems.
1. Lift landing floorboards, breathing flue downdraft gives you a vicious cold if more than a few minutes. No obvious smell, most likely black mould in chimney, fungal strep etc.
2. Downdraft from cold chimney would just vent it thro a fireplace vent.
Ceilings fine. Wood fine. No wallpaper staining. Redecoration up to fireplace panel showed no mould, plaster ok.
81yr relative will not agree to a vent in the fireplace panel (or its removal). Indeed I wonder if such a vent would just let in the cold downdraft & bugs?
Solution?
1. Run downstairs fire more frequently, vs monthly for 5hrs in winter.
2. Fit soffit-vent in the ceiling under the landing, which "ducts" straight to the upstairs flue.
3. Forced ventilation, at least to drop humidity level down, then vent.
Thus providing some direct ventilation from a permanently warm source.
All joists are rough sawn (just after WWII) so I am wary of any damp anywhere, upstairs cinderblock walls AND ceilings sit on joists.
Ironically I wonder if *summer* is worst, because in winter all the heating will naturally heat the underfloor area so aiding an updraft (although limited by meagre ventilation).
Q - Advice?
