Dark marks on bedroom ceiling

[emmaamme]

Hi, I live in a 4 yr old bungalow and noticed last night one of the bedrooms has dark marks on the ceiling mostly along the edges. They seem to have just appeared all of a sudden. It is at the back of the house, doesn't get a lot of sun & has 2 outside walls. Had a look in the loft but couldn't see anything untoward. Any ideas?

 

[^woody^]

Pattern staining from a cold spot caused by the joists or lack of insulation. Dust/dirt is attracted to the cold spot. Add more insulation above

 

[emmaamme]

Thanks Woody. Haven't any experience of insulation. Should we put more on covering the whole room or just the sides? Any recommendations & will paint cover the marks?

 

[pilsbury]

Think 270mm of rock wool type insulation is the recommended level. All over.

 

[emmaamme]

I think the entire attic probably already has the recommended level as the house is only 4 yrs old. What would you recommend as a top up?

 

[pilsbury]

I doubt you’d want to go over the 270mm. Law of diminishing returns. Just check the edges.

 

[^woody^]

I think the entire attic probably already has the recommended level as the house is only 4 yrs old. What would you recommend as a top up?

But is lit laid properly? What's the cover over the timber, any gaps around the edges?

 

[emmaamme]

Hard to tell tbh as difficult to get close enough to check due to sloping roof. Got a roofer coming in Jan to replace some tiles so will ask him to check it out (assuming it would be his line of work rather than a joiner?)