Flies Frustrated?

Some of you already know that we have had immense problems with cluster flies getting into and being unable to get out of our wonderful roof room.

Throughout the summer I have been investigating how the little perishers are getting in in the first place. Clearly, flies can get into an enclosed room via the doors when open - but not in their millions.  I took apart the roof overhangs and found 101 ways in to the flat roof space.  It need to be ventilated after all.  Once in there they need to find a way though the ceiling and there are gaps aplenty - most obviously round those inset little ceiling lights.  There is, in cluster fly terms,  a massive gap between the LED bulb and the lamp housing.  I abandoned all of those and replaced them with 500mm x 500mm square flush-to-ceiling LED panels, suitably (I hope) sealed.  That alone may have done the trick but I shall never know.  The lights are brighter and better anyway.

On the outside I have sealed every gap between cladding panels with backer rod (Google it) and roofing sealant.  That just left the half dozen or so round vents in the undersides of the overhangs through which flies could fly with their eyes closed on a near constant current of air if the vents were doing their intended job.

Each of those vents has been inelegantly but firmly sealed with minute stainless steel fly mesh and silicone sealant (lower).

The fly season will soon be upon us and I shall report further. 

Here is a reminder of the scale of the problem - dead flies surrounding the space in a corner of the roof room where a cylinder vacuum cleaner had been standing.