Make underfloor air vents mouse proof

[robgraham]

Dave Liquorice in the thread about a power failure alarm for a shed, mentioned using a baby alarm to listen for the mouse traps going off in his attic.

I do suspect that that is a leg-pull, but it did remind me that having got rid of this autumn's ingress of unwelcome guests from the local fields, it would be sensible after all these years here that I did something about making it a bit more difficult for the little blighters to get in.

There are something like 7 traditional (they were fitted in the late

1920's) cast iron vents round the cottage just above ground level. The grill gaps will be considerably greater than 7mm so don't really present much of a barrier.

Any suggestions about some modification that wouldn't look too naff, but would reduce my need for the baby alarm !!

Rob

[Dave Liquorice]

Nope, serious. We live trap so the little blighters rattle their cages trying to get out. We've found if you get them early in the season that is it for the winter.

I think the best bet would be to remove them, fit some suitable fine wire mesh behind or in them and refit.

[Tim]

I found that this:

a decent 'tray' that nestles up to the grate, then secured with ties.

Rob

[John Rumm]

To add to that question a little... is there a definitive answer on whether they pesky things can get through a modern style of airbrick:

fitted many of these to our place, it might explain one way the things get in!)

[Dave Liquorice]

Depends what you mean by "get through", is that plastic? If so if they really want to they will gnaw their way in... Other than that how big are the holes, anything bigger than about 6 mm dia is big enough for an adult mouse. The limiting factor is their skull and if required they can dislocate the plates...

They may well be just climbing up the walls to the eaves.

[Brian Gaff]

Yes I had to do this with normal air bricks here to stop determined wasps from building nests between the floors of my house. metal mesh is best as its not as easy to chew through or prone to weathering as plastic.

Brian

[Tim Lamb]

I once watched a Shrew wriggle through a 7/16" hole. One shoulder at a time but successful.

As Dave says, mice are able to change the shape of their sculls. Our loft/garage crop this Autumn were all Wood Mice which are much bigger.

Garage access, I think, was up a brick pier and through a gap at the soffit. Now blocked with expanded metal. The evidence was the disappearance of some stored Daffodil bulbs:-)

I have trapped 5 or so in the loft and still don't know how they get there. I thought the problem would be cured when the extension closed off an opening in the cavity wall next to a timber barn. Most of the single storey structure is feather edge clad, giving a clear route to the soffit....

>

[robgraham]

Thanks Tim - that's what I will go with. The idea of lying on the ground trying to cut the current grills out to make a neat job of hiding the mesh doesn't appeal too much; if it is just too horribly obvious I might change my mind, but I'm hoping the mesh will weather and anyway who looks that close to the ground.

Rob

[Dave Liquorice]

Ha dumped a shrew that had either wandered in or the cat had bought in into the mouse cage. It ran straight out as if the bars weren't there, mice don't get out.

As for the galvanised mesh on the outside of the air vents, it won't weather in it will stay bright zinc coloured. This is why I suggested removing the vents and fitting the mesh behind as the OP wanted something to look nice. I guess you could paint the mesh, if you can find something that will adhere to zinc wire outside.