I've got a floor joist that is low between 3/16 and 1/2 in. Because of its position, I can't sister it. How can I level it? Can I rip a 2x4 and glue and screw it to the top? Would it be stable or compress over time? I've read that it's possible to use strips of asphalt shingles to level a joist. Can I stack them a 1/2 in. or is that too high? Are there other options?
If it is possible, use the ripped down 2X4. The built up shingles will work for a while, for I think they would compress over time since the asphalt or the derivative of it will move if given reason to.
If there is no room for sistering a full sized joist beside it, perhaps just a 2X4 glued and screwed to the side? Just in case the reason why it cannot be sistered otherwise is from utilities passing through the way. A notch here and there will get past issues too.