Ceiling discolouration

[C8PPO]

We have had tenants in a property for approx 6 months. Prior to that we lived in the property for c. 3 years.

On a visit today to repair something, we noted that the ceilings in both the sitting room and the bedroom are all showing black staining which follows the lines of the joists above; in other words, the outline of the joists is clearly visible. Whilst we haven't specified non-smokers, we do know the tenants and as far as we are aware neither are smokers, at least not heavily or regularly. There are no open fires, only electric storage heaters and one small portable convector. The property is a second/top floor flat, purpose built, brick & tile, with a large loft space above.

Clearly we'll ask the tenants but wondered whether anyone had an idea what could be causing this?

Thanks.

[henrycrun]

Have you checked the loft? I'm recalling a friends story of woe when a leak in their loft went undetected and turned into someting much worse - ultimately the ceiling had to be replaced

[Tiggsy]

WATER!!!! Get above it and look.

[C8PPO]

Tenant has 'fessed up to candles!!

[B17NNS]

C8PPO said:

Tenant has 'fessed up to candles!!

Hardly a crime now is it?

Still can't understand how this would discolour only the areas where the joists meet the boards.

Id still be tempted to take a look in the roofspace. Sounds more like a potential damp/condensation issue to me (moisture wicking through the ceiling joists and into the boards?)

[ThatPhilBrettGuy]

B17NNS said:

C8PPO said:

Tenant has 'fessed up to candles!!

Still can't understand how this would discolour only the areas where the joists meet the boards.

It does though. I suspect there's a subtle difference in the static electricity properties. Ours has done exactly the same....

[Engineer1]

I'd still check the loft, with the standing snow at the start of the year water may have soaked through the roof or found any weaknesses in the weather proofing.

[robinhood21]

Probably just electric heaters + cheap emulsion on the ceiling.

[C8PPO]

I'll have a look at the weekend. No, candles are not a crime - just wondered how the discolouration got there in the first place and we didn't know about/there was no trace of substantial candle consumption.

[Simpo Two]

ThatPhilBrettGuy said:

I suspect there's a subtle difference in the static electricity properties. Ours has done exactly the same....

Static through 12mm of plasterboard? I was thinking along the lines of temperature differential.

BTW if you want to see static, move a metal tape measure across your CRT TV and then touch one end on your metal hi-fi!!

[Wings]

http://www.inspectapedia.com/interiors/ThermalTrac...

[Simpo Two]

Thermal tracking. Yay, win to me