I recently had a new wood floor installed and I am concerned about some gaps between the quarter round and the floor and between two wood to tile transitions and the floor.

I have been reading that quarter round should be flexible enough to sit flush to the floor. I am not sure if there is any tolerance for a gap, but my research indicates there is not because you want to keep bugs and debris out. My installer says there is an 1/8" tolerance for these gaps, but I don't think that is correct. He also offered to caulk the bottom of the quarter round to fill the gaps, but I am reading that that is not recommended because it is a magnet for dust and dirt and hard to clean and also may affect expansion and contraction of the floor. Also, this is a glue down installation and the installer leveled the slab before the install.

Please tell me what you think. Should the quarter round be perfectly flush to the floor? is there any tolerance for gaps? Are these gaps within any tolerance? Should anything be done to correct them? Should they be caulked, should I ask the installer to redo the quarter round? Any other possible solutions?

What about the transitions? I already saw a small spider sneak under the one in the second to last and third to last pictures. And the one in the last picture is in the kitchen where a lot of debris ends up on the floor and I'm afraid it will be swept under this transition.

https://imgur.com/a/ym74G1J

I struggle with this on a lot of sites and this is the number one reason I befriend as many of the carpenters as I can

Easy fix - just remove and reset the shoe. You shouldn't push down on the shoemold at all when you reset it, as you don't want to pin the floor anywhere, but there's nothing that says you must be laser level straight either. So I would go along and as I'm nailing the shoe back in, just push it flush with the floor and secure. This happens when you have a different trade doing the shoe and the floor installs - a carpenter is taught to install level with a laser, but a flooring guy will contour the shoe to hid the gap, since we know that 'level' isn't as important as 'flat'

As for the transitions - you need a different reducer it looks like. That will allow the end on the low side to sit flush. Take that photo back to the shop you got the hardwood from and they should be able to supply a more appropriate piece.

Thanks for your reply.

The flooring manufacture only offers this one reducer. Do you think that a clear caulk under the gaps on the reducers is a viable option?

Quarter round is sometimes not suitable for floor trim. The correct trim is base shoe. Either one will cover any gaps. Quarter round is hard to nail to the base correctly without being very careful to nail parallel to the floor instead of nailing at a 45 degree angle. The base shoe is made with a flat side that goes against the base so it is easy to nail into the base with nails parallel to the floor. When the floor has a slight bump, which means a gap somewhere, a block plane can remove a little of the bottom of the shoe to help it conform to the floor without taking a lot of shavings off. The quarter round will be more work. It may touch the floor right against the base, but since it is 3/4 inch wide at the bottom, it may have a gap at the front. To plane the whole bottom of the piece will take more effort and the gap may not even show until it is fastened tight to the base board.
Using quarter round instead of base shoe is a pet peeve for me. A sophisticated consumer will ask for shoe instead of quarter round trim where the base meets the floor. What can you do when the quarter round comes refinished to match the flooring specially made for your pre-finished flooring? Well, if the directions say to leave a 3/4 inch gap between the floor and the wall, the quarter round may be the trick.
Using a clear caulk to fill any gaps that should have been taken care of with a block plane will make a real mess.

Thanks for you response. I wish we could have used base shoe, but it would have been a mismatch to the quarter round already in other connected areas where there is tile, and since this is not a forever home we opted not to replace all the quarter round, although I wish we had now.

Any thoughts on the transitions?

Transitions are where the floor mechanic shines. A careful inspection will tell whether they fit well and are going to last. All floorlaying talents and experience are not required for all transitions, but experience will show.

I’m confident that I was misled on the amount of experience my installer told me he had. Like I said, this is a fairly short term house, so I don’t need the transitions to last forever. Do you think clear caulk will alleviate my concerns about bugs and debris for a few years?

You must have a lot of insects around to notice any inside your home. Vacuuming will clear your house if done regularly, and rid it of dust and most grit.
The clear caulk will do neither.
I find that caulk will shrink, and sometimes turn a light gray color if white caulk is used.