The awl went in up to the handle. I'd pushed it into the bottom of the garage side door jamb expecting the little bite you get from sound pine, and it slid in like the wood was a stick of butter left out on the counter. I moved up an inch and tried again. Same thing. It took about six inches of climbing before the point finally stopped where it should.
This wasn't exactly news. Last summer, right after I bought a $30 pin moisture meter, I walked around the property poking it into everything, and the bottom of this jamb read far wetter than the rest of the frame. I wrote the number in the house sheet and then let it sit there for ten months, like slow-moving stock nobody wants to deal with.
Why the bottom of a jamb rots
Our garage is from 1952, and the side door frame sits right on the concrete slab. The bottom of each jamb is end grain, which pulls water up like a bundle of straws. Rain hits the step and splashes the base of the frame, and the old door sweep had been flattened and torn for a while, so wind-driven rain had an easy way in. We painted the garage last July, and I painted right over this spot. Paint keeps rain off the face of the wood. It does nothing for wood that's drinking from the bottom.
On Monday evening, July 6, I went back with the meter. At the very bottom of the hinge-side jamb it read at the top of its range. Ten inches up, it read normal, right in line with the rest of the frame. So the damage was real, but it was local.
Patch or replace
Gary came over to look, because Gary always comes over to look. His vote was to cut off the bottom foot of the jamb and splice in a new piece of wood. "Water always wins," he said, tapping the slab with his shoe.
I weighed three options. Replacing the whole jamb meant pulling the door and the casing on a 74-year-old garage where nothing is square, and I could easily trade a small problem for a door that sticks. Splicing in new wood was Gary's way and probably the most durable, but cutting a clean angled joint in place is a skill I don't have yet. Epoxy meant removing the rot, hardening what was left and rebuilding the missing part with filler that doesn't soak up water at all. With the damage limited to the bottom six inches and the rest of the frame solid, I went with epoxy.
Cut, dry, fill
That Monday night I cut the soft wood out with the oscillating multi-tool and cleaned up the edges with a chisel, stopping when both the screwdriver test and the meter said I'd reached sound wood. The hole ended up about six inches tall and an inch and a half deep. Then it had to dry. I pointed a box fan at it every evening that week and tacked a sheet of plastic over it before Thursday's rain. By Saturday the readings in the cavity matched the wood above it.
On Saturday, July 11, I drilled a few small holes into the remaining wood so the consolidant could soak in deep, then brushed it on until the wood stopped drinking it. Once it turned tacky, I mixed the two-part filler, packed it in and shaped it to the jamb's profile with a putty knife.
My mistake: it was 88 degrees in the driveway and I mixed filler like it was February. Epoxy sets faster in heat, and a big batch makes its own heat on top of that. Ten minutes in, the half still in the cup had gone stiff, and it went in the trash. After that I mixed golf-ball-sized batches and worked faster. I also kept the bottom of the patch a hair above the slab and sealed that thin gap with caulk, so the new end isn't sitting in the splash.
Sunday morning I sanded it smooth, primed it and painted it with leftover SuperPaint from last summer's garage job. You can find the patch if you know where to look. The new sweep went on last, trimmed to width with tin snips. The old one came off in two pieces.
The cost: epoxy consolidant $24, epoxy filler $28 and a door sweep $20, for $72, plus primer and paint we already had. The patch itself can't rot, but the wood around it still can, so the meter will visit that corner a couple of times a year.
Trip count: 2. One for the epoxy, and one to exchange the 32-inch sweep I bought for a 36-inch door.
