Dark stain on insulation

[emmaamme]

Any ideas what this dark staining could be on the top of my loft insulation? It's just on a small section near the eaves which are ventilated. It doesn't feel damp and no signs of a leak around it.

We do get cluster flies at that side of the house which tend to try to hibernate in the loft (I zap them with fly spray).

The bungalow is 7 yrs old.

I have seen similar on a recent roll of insulation that I bought although just a small amount so wondering if it could have been like that from installation 7 yrs ago?

 

[Wayners]

Mice.

Will smell if it is from mice

 

[emmaamme]

Really? Is it from their urine and should I remove that bit?

 

[Wayners]

I've seen similar and it stunk when i disturbed it.
I dumped what I found.
Go have a look

 

[emmaamme]

Just been back up and it doesn't smell. There's a couple of other small similar bits dotted around up there too. I've removed the bit in the photo. Couldn't see any droppings around. Might stick some traps up there and see I catch any.

 

[emmaamme]

Just been back up and found a few more patches.
The 1st one below felt a bit damp around the staining.
The 2nd one was sticky and left brown staining on my fingers

Not sure if they are droppings or not (they were beside the sticky bit in photo 2)

 

[Burnerman]

Good morning Emma
A mystery indeed.....have you had any roof work done, or checked outside for any shifting tiles or whatever?
If the area feels damp but not smelling, happily mice can usually be ruled out - their calling card is quite distinctive!
Regards
John

 

[emmaamme]

Hi John, nice to hear from you. Not had any roof work done & the roof seems OK visually. No evidence of staining or leaks above where the dark stains are on the insulation either. It's all very strange indeed. We do get cluster flies in the loft and I've seen bats outside at dusk occasionally but no signs of any bats inside though. The mind boggles.

 

[andy_nufc]

Look more carefully for droppings. In the middle of your most recent pic, on the insulation, there is something that looks like a black grain of rice. (It would be about the same size too - I can't tell how zoomed your photo is.) Are there more of those around?

 

[emmaamme]

Look more carefully for droppings. In the middle of your most recent pic, on the insulation, there is something that looks like a black grain of rice. (It would be about the same size too - I can't tell how zoomed your photo is.) Are there more of those around?

That's the only ones I've seen. It's a pretty big loft area but no other droppings beside the other stains (I've lifted the insulation around there to look underneath). No evidence of chewing or odour either.

 

[ajstoneservices]

I have seen similar dark staining on knauf insulation straight out of the wrapper.

 

[emmaamme]

I have seen similar dark staining on knauf insulation straight out of the wrapper

I have seen similar dark staining on knauf insulation straight out of the wrapper

Me too - a knauf top up roll I recently bought had a bit like that on it. Just a bid odd re the damp & sticky bits.

 

[ajstoneservices]

I always wear gloves when handling insulation so can't help with how it felt.