There are only two kinds of homes: Those that have squirrels, and those that will get them. Okay. I’m sort of joking here. But a good many old (and new) homes are prone to invasion by critters. Sometimes, it’s the result of poor construction or repair; but very often, deferred maintenance or inattentiveness by owners or occupants are the main contributors. I’m first to admit that, in my past, I’ve been guilty many times of the last two violations. But nowadays, I’ve no tolerance for preventable failures, don’t allow myself to perpetrate them, and don’t hesitate to make others aware of such situations whenever I notice them.
The Mansfield House, of course, has been no stranger to critter occupation. In the short time I’ve been here, I’ve discovered a bat living in my cellar, a possible skunk in the crawlspace, some ancient evidence of past raccoons, both ancient and more recent evidence of mice, and just very recently, two gray squirrels, who were regular sojourners in my attic. The main entry points for these squirrels (based on my neighbor’s eyewitness reports) were several openings along the roof’s ridge line:
These openings had resulted from an uncompleted roofing job done not too long ago for the previous owner, where some sheathing boards were replaced or moved, and the ridge was never capped. An errant subcontractor had been blamed, but that’s neither here nor there, at this point. I’d been an idiot to not have checked closer back in January, as none of this is easily visible from the outside. I just assumed all had gone well with the recent work (again, the sin of inattentiveness on the part of an owner). So let this be a lesson to never trust, and always meticulously verify, even if you’re convinced verification is unnecessary, or not worth your time.
Anyway, my strategy for getting the squirrels out was to close-up the obvious openings in the ridge, and one or two less obvious, older openings that I’d suspected might also serve as potential entry points. Then, catch the squirrels with live traps and release them to the wild [not exactly something I'd never done before -- some of you may recall my post "Hey Rocky, Watch Me Pull A Squirrel Outta My Attic (Again?!)", and the more whimsical "Squirrelly Goings On At Building Moxie And Beyond"]. There was, of course, quite a bit of urgency here, given the nonstop damage that squirrels inflict on the interior of a building, and the fact that grays in these parts tend to breed toward late spring, which was not too far around the corner:
So, I set about the exclusion phase first, by cutting a number of 15″x swaths of metal lath to length, forming them to the underside of the ridge wherever there were opened areas, and then stapling them in place:
Often, fitting the lath required trimming or rounding the edges where the lath was inserted just above, or butted up against, the rafter peak:
The largest of the openings in the ridge was at the opposite end of the attic, just at the south gable. Here it is, finally covered:
Now, here’s one of the much older and funkier potential critter entry points in the attic. The sunlight visible at the extreme left of the photo below is an opening to the exterior of the house, where the rear top plate of the frame penetrates the gable siding (and has done so for nearly 300 years now — nothing new). But the small line of light just below the foam board is an opening into the north garret. Yes, that’s right; warmed interior air leaks upward into the attic past the foam insulation, right at this point. But at least it’s nothing to worry about from a critter-entry perspective:
Looking more closely into the opening, just above the plate and to the left of the rafter that defines the north rake of the rear roof, revealed a chewed up plastic bag. Perhaps the squirrels had gone out shopping at one point, and then attempted to use their plastic shopping bag for sealing out winter drafts:
So I took a strip of metal lath, and formed it into a cone:
Then pushed the cone down into the opening between the plate and the rafter. So this potential entry point is also now excluded:
Finally, when I’d completed all the exclusion work I’d determined was necessary, I set the traps. But, I’d hoped that maybe I’d lucked out when it came to actually having to capture them. You see, this particular pair of squirrels seemed to be in the habit of spending long periods of time away from the house. Usually, whenever they happened to be around, and I entered the attic, they’d scamper under the floor boards. But their presence down there was still quite audible. On other occasions, when I entered the attic and was greeted by dead silence (no matter how loudly I tramped across the attic floor), I surmised they had left for a while.
On the day I’d done all the exclusion work, there was total silence in the attic. So I was hopeful they’d gone off on one of their squirrel jaunts, and I’d get all the openings sealed before they returned. But when I’d finished, I baited my Havahart live traps for them, anyway:
But over the past few days, I’ve caught nothing in my traps. And the attic is silent. So maybe my supposition was correct. Or maybe not. There could always be other entry points I’m not aware of. We’ll just have to see over the next few weeks whether the squirrels manage to make it back in. But I hope they’re gone for now. They’re much more appealing when they’re frolicking about in the back yard, rather than running amok in the attic.
Now that the squirrels seem to have been successfully excluded from the house, my next step is to temporarily cover the ridge from the outside with ice & water membrane, just to keep the weather out. Since my longer-term objective is to properly vent the ridge (as part of a broader and precisely controlled system of attic ventilation), the fact that the ridge wasn’t properly capped might very well be to my benefit, since it’s work I’d have to undo, anyway. But what I’m really concerned about is how much moisture got in during the time the ridge was opened. Some cursory scans of the sheathing boards forming the ridge show a relative moisture content of about 7%-9%, so the boards are actually in pretty good shape. Undoubtedly, this is because they’re able to dry out quickly enough, following any soakings. But I’ll also be checking for moisture under the upper courses of shingles and underlayment, as well.
Although no squirrels were caught, this effort did yield a quarry of sorts, consisting of a few interesting old iron nails I’d extracted from the sheathing boards in a few locations where they would’ve blocked the lath:
Most of these nails had once secured sheathing planks to the rafters, but were gradually pulled out as the rafter pairs shifted over time. Three of these nails appear to have been clinched against their planks. The small nail, third from the left, I believe to be an old shingling nail used on a wood shake. The nail in the center is a 3″ machine-cut nail, identical to the ones I’ve found extensively throughout the Hawkins House. Finally the nail at the extreme right is a true hand forged nail — both its shank and head had been completely shaped by a blacksmith.
So, I hope you’ve all enjoyed this article of squirrelly and critter mayhem. It’s not the first I’ve written on this topic. And I’m sure it won’t be the last….