Mould stains at edge of bathroom ceiling

[Longshanks]

Hi

Edge of bathroom ceiling constantly showing black/mould stains. Have painted over several times but these always quickly return.

I’d previously understood it could be poor insulation at the edge of loft resulting in colder surface at that point.

It’s a conundrum, as deliberately left a few inches between insulation and eaves. Also looks to be adequate height at that point. (Also no staining at edge of adjacent bedroom)

Have extractor fan in bathroom.

Any wisdom would be appreciated.

Thanks

 

[JohnD]

Your bathroom is damp. Do you have steamy showers?

What sort of extractor do you have, and when do you use it?

The wall is probably cold. Is it a cavity wall?

Show us the eaves and insulation. You can get eaves vents that keep the channel open and allow insulation up to them.

 

[Longshanks]

Hi

1. I don’t but wife and son probably do.
2. Inline extractor fan replaced about two years ago,
3. Assume so.
4. Photos attached. Bit of a conundrum. Need to leave ventilation gap but that risks colder edge of ceiling.
5. Eave vents? Any links would be greatly appreciated.

Thanks

 

[Longshanks]

To add:

The insulation in that area took a pounding when the spark replaced the fan.

 

[JohnD]

Show us your extractor. And the duct. When do you use it, and for how long? I think you need better extraction.

Example of eaves vents. They keep an air channel open and you can insulate right up to them. If you buy a new roll you can relay it better.

Manthorpe 600mm Refurbishment Eaves Vents G645

The Refurbishment Eaves Panel Vents are designed to maintain a flow of air to the roof space from the eaves. Designed to be used in refurbishment situations and is fitted from inside the roof space to create a clear air gap between the loft insulation and felt, its flexible hinge enables it to...

mytradeproducts.com

I see your house is quite modern. Presumably if has cavity walls. Do you have CWI?

 

[Harry Bloomfield]

2. Inline extractor fan replaced about two years ago,

When, or what cause it to run and for how long?

Best is PIR operated, with a 20 minute run time, annoying when you just go in for a pee, but better than mould on the walls. Besides, bathrooms have moisture in them, long after baths and showers, as surfaces dry off - the extra triggering, is not entirely wasted.

 

[Longshanks]

Show us your extractor. And the duct. When do you use it, and for how long? I think you need better extraction.

Example of eaves vents. They keep an air channel open and you can insulate right up to them. If you buy a new roll you can relay it better.

Manthorpe 600mm Refurbishment Eaves Vents G645

The Refurbishment Eaves Panel Vents are designed to maintain a flow of air to the roof space from the eaves. Designed to be used in refurbishment situations and is fitted from inside the roof space to create a clear air gap between the loft insulation and felt, its flexible hinge enables it to...

mytradeproducts.com

I see your house is quite modern. Presumably if has cavity walls. Do you have CWI?

I’ll have to go back in loft and pull up insulation to expose fan. I’ll also take a photo of the duct. It’s activated when light switched on and then 5 mins afterward (think) We all use it religiously.

Vents-thanks

 

[Longshanks]

When, or what cause it to run and for how long?

Best is PIR operated, with a 20 minute run time, annoying when you just go in for a pee, but better than mould on the walls. Besides, bathrooms have moisture in them, long after baths and showers, as surfaces dry off - the extra triggering, is not entirely wasted.

Think I’ve answered this in above post. Don’t think it runs for 20 mins after deactivating.

Thanks again.

 

[JohnD]

It’s activated when light switched on and then 5 mins afterward (think)

As the mould is caused by excessive moisture, adjust the timer to max. Probably around 20 mins. There is pretty sure to be an adjuster.

 

[Longshanks]

Ok. Thanks

 

[Harry Bloomfield]

It’s activated when light switched on and then 5 mins afterward (think) We all use it religiously.

Longer would be better, I set mine to 20 minutes, they cost little to run.