chuckey
Member
- Messages
- 883
- Location
- wenslydale
I had my traditional rock and rubble re-roofed about five years ago, complete with a modern sarking cloth. I then returned to decorating the main bedroom, which although tatty was basically sound, this included partitioning a portion of into a en-suite shower room. As a challenge I decided to include a heat exchanger into the air outlet and air inlet for the en-suite to try and conserve some of the heat.
So far so good, after about a year a large brown stain appeared on the wall in which there is a flue, this stain also crept from this wall out ,along the ceiling by about 12". For various reasons we chose to ignore this stain until recently, though in the mean time I installed 3 double air bricks into the gable end walls because I thought that the ventilation in the loft had been compromised by the sarking cloth. So now here it goes, two coats of stain blocker paint and two coats of emulsion, after some months the stain had crept through. Then two coats of aluminium paint (as a traditional stain sealer) with another two coats coats of emulsion. A month or so passes, still the stain re-appears. This time I tried two coats of "Zinsser" stain sealer with more emulsion, all to no avail.
So I went up into the loft to see if I could see anything. it would appear that the two year old, installed ali air ducting had been perforated along its top and bottom. it would seem that lime dust had been blown around in the loft and had settled on the pipe and on the plastic drip sheet under it and with moisture from condensation had eroded the aluminium. So I am hypothesizing that the damp air, so released, has been condensing on the gable end, running down it taking some of the soot compounds with it which will continue to soak into the ceiling until the leaks are repaired (new plastic pipe!!!)
So just because its a new pipe and is not in direct contact with any lime, in the end the aluminium will corrode due to wind borne lime particles.
Frank
So far so good, after about a year a large brown stain appeared on the wall in which there is a flue, this stain also crept from this wall out ,along the ceiling by about 12". For various reasons we chose to ignore this stain until recently, though in the mean time I installed 3 double air bricks into the gable end walls because I thought that the ventilation in the loft had been compromised by the sarking cloth. So now here it goes, two coats of stain blocker paint and two coats of emulsion, after some months the stain had crept through. Then two coats of aluminium paint (as a traditional stain sealer) with another two coats coats of emulsion. A month or so passes, still the stain re-appears. This time I tried two coats of "Zinsser" stain sealer with more emulsion, all to no avail.
So I went up into the loft to see if I could see anything. it would appear that the two year old, installed ali air ducting had been perforated along its top and bottom. it would seem that lime dust had been blown around in the loft and had settled on the pipe and on the plastic drip sheet under it and with moisture from condensation had eroded the aluminium. So I am hypothesizing that the damp air, so released, has been condensing on the gable end, running down it taking some of the soot compounds with it which will continue to soak into the ceiling until the leaks are repaired (new plastic pipe!!!)
So just because its a new pipe and is not in direct contact with any lime, in the end the aluminium will corrode due to wind borne lime particles.
Frank