Q: I’m installing Patagonia Rosewood, which is listed as having a 3840 Janka Rating. I can’t find nailers that go up that high in terms of what they will handle, but it appears 20-gauge goes the highest in terms of what it will handle on hardness end. Problem is, flooring is 3/4″. Sub-flooring is also 3/4″. That would be okay, except to level the floor we had to add roofing felt in places, and will still have to level out some spots with roofing shingles. This can add up to 1/4-1/2″ of depth.
I can only seem to find 18-gauge nails in 1.75″ lengths, and 20-gauge in 1.5″ lengths.
Neither seem long enough, but I guess my question is what nail and nailer to use given I can’t pull everything up and start over leveling from the joists at this point (glued and screwed sub-floor). Better to go 18-gauge, even though more likely to cause splits, to gain that extra .25″ of length? Or better to go 20-gauge, so fewer splits, but only getting 19/32″ penetration into sub-floor where no leveling material exists, and as little as 3/32″ penetration into subfloor in some places? Help?
A: You should be using a proper floor nailer-Primatech, Powernail etc which fire cleats, two inches long and 15 gauge. 18 gauge and up? These are pins for trim work, not a 3/4″ very hard wood floor. that shimming is also excessive. You would be better to try to also grind down some of the humps because the 2″ long cleat will only extend beyond the bottom of the board, maybe 1 1/4″. Best to get, even if you have to rent it, such a nailer that runs off a compressor and air pressure.
Incidentally, a floor nailer, not a trim gun, sits on the edge of each board and fires the cleat flush, through the top of the tongue on the board edge.
A final suggestion. Strap on the knee pads, pre drill each hole, going on an angle through the top of the tongue and use 2″ long, spiral finishing nails. Tap them down with a nail set flush with the top of the tongue, spaced every 7″. I’d be surprised this floor stays down the way it sounds you have been proceeding.