Two Grinders Are Twice as Fast — Rent, Don't Buy

Day five. Before roof and insulation work could begin, the ceiling plane itself had to be cleaned up.

Removing the ceiling battens. After the old ceiling finish came down, dozens of wooden battens — the supports for the false ceiling — were still nailed across the structure. They’d block both the insulation and the final plaster, so every one had to come off with a claw hammer and crowbar. Far more nails and screws than expected; far more time than expected. Honest note to ourselves: this should have been in the demolition contractor’s scope from day one. Next project, it will be.

The two-grinder discovery. One grinder wasn’t producing enough progress on the ceiling timber, so yesterday we bought a Bosch grinder for ₩60,000 at the hardware store and rented a second one for ₩20,000. With my brother and me each running one, the pace roughly doubled and each of us tired more slowly. The real lesson is in the rental: short-duration tools are cheaper to borrow from the hardware store than to own.

Solving the foam-board fixing problem. We gave yesterday’s urethane-foam-only test a day to cure, then checked: not good enough. The bays between rafters aren’t flat — nothing in this house is flat — so adhesive alone can’t hold the foam board tight forever. It would work loose.

My brother proposed the fix we adopted: urethane foam adhesive as the first bond, then steel hinge-pins driven into the rafters to pin the board mechanically in place. Belt and suspenders. The pins hadn’t arrived yet, so today we fixed the boards temporarily with foam and screws.

That closes the preparation for roof insulation. Next: stripping the roof tiles in earnest, and finishing the interior with foam board behind plaster.