Filling A Gap with Foam

As promised last time, today I worked on plugging up that rodent hole at the back of the dormer. First off, here's a better picture of the gap:

There's a lot more copper mesh in there than it appears. It's there to capture the foam filler, to impede its progress so that once the mesh fills up, the foam backs up and fills the front of the gap solidly rather than simply continuing to move inward. Copper mesh is available from gardener suppliers, but in a pinch a copper pot scrubber would serve perfectly well.

As I mentioned, I obtained foam filler that is intended specifically for filling exterior building cavities such as this one. This is not the type of foam one generally sees at Home Depot, intended for filling gaps around windows and doors (although it serves for this purpose as well); it's denser, thoroughly weatherproof, and expands instantly. I purchased it from Gempler's, which is my supplier of first resort for a majority of my Farm House maintenance needs. 

I must admit, I was pretty daunted by this new, super-duper foam, because it comes in a huge can and is applied with a pretty impressive-looking gun.

This rig fairly shouts PROFESSIONALS ONLY, and as silly as it sounds, I wondered whether I had the chops to wield it effectively.

As it turned out, it's much easier to use, because the volume of foam is minutely controllable using the adjustment knob at the back of the gun, and the speed of its exit is easily modulated using the trigger. Thus, after some practice shots in the garage and some adjustments, I was able to place the foam right where I wanted it as easily as putting toothpaste on a brush.

After a half-hour of curing, I was able to cut the foam back to its intended boundaries with a utility knife.

It's not terribly pretty from this close up, but from the ground it blends in undetectably. Now, the gap is filled more or less permanently, impervious to critters and the weather.

One last point about this foam rig: if you leave the can on the gun, clean off the tip and close the adjustment valve completely, the foam will stay fresh indefinitely, so that you can keep using the can until it is empty. The Home Depot types that dispense directly from the can are good for one use only, no matter how little foam is actually used, because the foam cures in the applicator tube and blocks the exit of the remaining foam.

That's huge, because not only does that make this system more economical despite the cost of the gun, but it means that as I find any gaps as I work from now on, no matter how small, I can quickly and easily fill them with little added cost or fuss. I wish I'd had this rig from the start of the work.

And with that, it's time to start masking so that I can paint.

* * *

"I remain thoroughly disgusted by the rank 
anti-rodent bigotry of this establishment."

"No rodents, no peace!"

Fun with Dormers

Since last I wrote, I've been busy repairing, sanding and patching the dormer. It's taken a long time because of the vagaries of weather, and the sheer difficulty of reaching the back and top of the dormer. To sand the very top, I found it easier to climb up on top of the dormer and reach down.

The view from the crow's nest.

Complicating matters further is the fact that the level of the new roof is over an inch lower than that of the previous roof. The old roof consisted of wood shingles sandwiched between layers of sheet roofing on top and substantial redwood slats underneath. The new roof is one layer of plywood sheathing with three-tab dimensional asphalt shingles on top. The receding roofline left in its wake lots of wounds and irregularities where the formerly submerged dormer cladding was uncovered, and an awkward gap underneath where the cladding ends and the underlying structure is exposed. I'm still not sure how that gap will look when the dormer is painted; in fact, I'm not sure just how much detail will be visible from the ground, so I'm uncertain just how detailed I need to be in my patching. I may have to do another round of patching after I prime.

Here's what the dormer looks like right now:

The push broom is there to provide a handhold when working on the furthest extent of the sides (the broom head is securely attached to the handle and well-braced).

You can see that the sides are pretty messy, but I'm hoping that a good coat of paint will take care of that.

One more detail remains before I can mask everything off and start to paint. There's a gap at the back of the right side between the eave trim and the roof that opens up to the inside. This is just the kind of thing rodents use to get into attics, and it needs to be plugged up. We did have some hardware cloth covering the gap, but I'd like to replace it with something more permanent, and more presentable.

Here's a picture of the gap:

It's larger than it appears here, but in any event, you can see a bit of shiny copper material peeking out from inside the gap. This is copper mesh. Gardeners use it around planters to keep snails out; pest control people wad it up and stick it in gaps like this to serve as a backing for insulating foam filler. You will recall that I used a foam filler to fill a gap underneath the new window in the south side; the foam I will be using here is similar, but is specifically designed for this kind of situation. It's completely weatherproof, paintable, and impervious to rodents.

It's also a big mess, so stay tuned. This should be fun.

* * *

"I don't see why you don't just let the rodents come in, you spoilsport."