Red / brown dust in bathroom

MisterNick

Thanks Stuart, I'll park dry rot for the time being.

JohnB47

I'm wondering is there is a gap within each of the recessed light fittings - not around the outside of the fitting but around the actual bulb, within the fitting - to provide a level of heat dissipation. If so, dust from the loft could be falling or even being sucked in through those gaps.

Another thought is for you to carefully look along the top edge of your bathroom door and maybe along the inner edges of the door frame. These areas in our bathroom collect a fine dust over time, simply because of normal house dust being drawn into the bathroom. It take many months to show however and is very fine. Just wondering if your areas are unusually dirty. If so, it might indicate dust originating elsewhere. If not, dust getting in by some other path.

Finally, I might try covering the extractor vent temporarily and not using it for a few days. See if the room still gets dusty and when, you remove the cover, see if dust has come in through the extractor while not in use.

Albermarle

How about some wide masking type tape over the lights and extractor. Any dust coming down will stick to the tape.
I do not think LED will get warm enough to melt the tape but probably best to have the lights off. 

ThisIsWeird

MisterNick said:

Right, I've been the loft - its not in a very accessible place.
I took the flexible tube from the shower grill to the pump off at the pump end, and it was very dirty. Cleaned it as best i could.
 I could not see a non return flap (non function or otherwise) as Niv describes, but this could be the problem. I'll answer Niv's post below.
Took the cowl off the pump which was very dirty and cleaned that and the blades. 
Checked the blades rotated when switched on and put it back together. 
The pipe from the pump to outside is less accessible.
Heres's some pictures.

With the wind in a certain direction - coincidentally almost always when I've just started shaving - a hoolie comes out our bathroom extractor grille, and lands right on my head. Very unpleasant.
I didn't fit a n-r flap either.
If you are near-certain this dust ain't coming from the house, then the extractor vent has to be under suspicion.

Niv

MisterNick said:

Niv said:

Just a thought, you mentioned building work going on. Where is the building work in relation to the vent from your extractor? And, does your extractor have a (functioning) non return flap - they don't all have this feature. If its dust it could be coming in from the extractor when its not turned on and when building works are throwing lots of dust around?

Niv, Thanks for this thought.
There is no non return flap that I could see, although I suppose it could be on the vent. Can these be retro fitted? 
The vent is on the back of the house above where we had an extension built last year. we have also been having the garden done since last year. It is why we closed the window thinking this may have been the source.

I do not believe they can be retrofitted, my extractor fan had it integrated. Extractor fans don't cost mega bucks so may be worth replacing it with one that does have one.

Also, looking at the dust on the white bit of paper - it looks pretty similar to the dust on the extractor fan.

I know this may go against instinct, but you could cover the fan for a while and see if the issue stops (bit of paper taped over). Presumably this happens fairly quickly so we are only talking needing to do that as a test for a couple of days?

Grenage

A non-return valve can be easily fitted.  You just need to cut the ducting and insert a butterfly valve or the like.