In our last exciting episode, I got an early mouse in the bedroom heater’s firebox. Not allowed. They’re getting in through the exterior vent.
Sidebar: Mice in the vent is not ever mentioned as a possible problem in ads for the benefits of vented heaters.
Anyway: I covered it with plastic and duct tape yesterday morning, but Regular Commenter Ben came up a good (and in hindsight perfectly obvious) idea: What about hardware cloth? You could just leave that up permanently.
Huh. Why didn’t I think of that?
One reason is that I don’t like working with hardware cloth very much. That wasn’t a good reason not to give the idea a try.
Forming a useful mouseproof cover wasn’t going to be easy without some sort of circle form. Fortunately the cover is 9″ in diameter, which is a common dimension. A tin plate I use for collecting screws was perfect.
Snip, form, staple, snip, form, staple…
…and now we run into a problem I did anticipate: Getting the edge between the cover and the vent to actually keep mice out. If I left the edge of the cover as bare wire, it would hold to the vent pretty well. But it would inevitably leave gaps plenty big enough for a mouse to pass. False security.
So I reluctantly wrapped the edge with duct tape. That eliminated the mouse-size gaps, but unfortunately made the edge slick enough that it would no longer hold to the vent by itself.
And so I finished by doing something I had really resisted: The redneck’s friend…
(sigh) Duct tape. It looks like hell. It will keep mice out, and I don’t have to take it on and off seasonally, but I really want a better way to attach it.
I did something like this for my wood stove vent to keep birds out but I did it as a band sized to and wrapped around the open vent part versus a cap over it all. Used .032 wire twisted to keep it shut and no more birds in vents. I also used the same thing on a high eff. furnace vent but with smaller gauge holes to keep out miller moths. You could put a couple sheet metal screws in base and twistwire the wire cap to the base versus duct tape, then you wont have to remove it for the season.
Make about a 1/2″ flat lip on the hardware cloth and then use screws or nails to secure it to the siding
Just fire up the wood lathe (that you built from old car parts, alien bones, and pallets) and turn a ring to slip down over it.
Just kidding, duh, but you could do the same with a sabre saw or maybe the sawzall and a piece of 3/4″ plywood. Use screws around the inside with washers to tie the hardware cloth cylinder to the inside of the ring, and then a couple screws to bolt the assembly to the wall.
Nice work & hopefully this will do the trick. What Malatrope wrote about making a ring from some scrap plywood is a great idea and I’m sure it would solve the gap issue.
You should still be on the lookout for mice infiltration though. The hardware cloth size looks bigger than 1/4 inch. If it is, your furry little nemesis may still get in.
Could you use an auto hose clamp? Just slide it over and tighten it? Of course, you woyld need a large one.
That looks like 1/2″ mesh to me so you may still have problems.
Why not take the house side plate loose and tuck the edges under and caulk it again?
Will the cover/louver support unscrew and you can put the mesh inside the supports? Might not work but it is hard to tell how much space is there in the photos.
the redneck’s other friend: baling wire, or coat hangers, or tie wraps, etc
Joel, what is the accurate diameter of the exhaust vent and how tall from wall to the top plate?
I have all this welding equipment here and can easily (I think) fabricate a 1/4″ mesh top hat for it that will have a steel plate (giant washer) at the base that you can screw directly to the wall. If I make it 1 inch larger diameter and 1 inch taller, it should guarantee fit. Just send me the specs and let me play a bit 😉
Oh, gee, Terrapod, that would be great. Simple as pie: it’s 9 inches wide and 4 1/4 inches high.