What exterior caulk to use in winter

[Radian]

In my thread about attic mice I was looking at how they're getting in and came to the conclusion it was from the dormer window, through the big gap at the ends of the soffits:

 

 

I've given up worrying about rain bridging to woodwork so I'm going to try plugging the gap (about 25mm) first with closed-cell rigid foam (like the product used as expansion strip around UFH) then overcoated with a caulk.

 

But at this time of year acrylic frame sealant will take months to harden and become rainproof so I'm going to have to use something different. I've only ever used acrylic frame sealers so I'm not sure what might be suitable. I was looking at this silicone stuff...

 

It's usually used between UPVC frames and brickwork so not meant to be overpainted so that might be an issue as my fascias are wooden.

Can anyone recommend a different product?

 

Stixall is the only other thing that comes to mind but I regard it more as an adhesive. It says its a sealant as well but I think it might be too runny.

 

[gaz_moose]

i sealed the gaps in my concrete sectional garage with screwfix own brand exterior caulk about 2 years ago and its been fine so far. although i think a 25mm gap is to big for caulk, personally i would stick some PVC trim up, no one is going to notice it all the way up there.

[markc]

How about leaving the shadow gap and filling the void with expanding foam to stop them getting in.

a wide caulk/filler bead would look like a bodge job.

or cover the gap with some flat white pvc trim

[Simplysimon]

expanding foam with some stainless mesh so they don't chew through, trim back and cover with lead mate ot black silicone to disguise

[Radian]

I'm not too keen on anything that builds up beyond the fascia i.e. cladding with UPVC. I've resisted the drive towards plastic for this kind of application although I'm not sure how much longer I can hold out! I guess markc's idea of a shadow gap might look the least conspicuous.

 

I may regret this statement but I'm pretty sure there's no need for SS mesh reinforcement as I think this is just opportunist mice exploring an inviting looking hole. Experience has shown that passing trade happens on average once a fortnight - an indicator of the mean density of mice in my neighbourhood. It would be different if they were on the inside trying to get out though! 

[larry]

Sikaflex EBT is excellent. Sticky. Lasts well outside. A bit pricey.