Gaps and nail holes

What can be done about gaps and nail holes

Many floors have gaps between boards due expansion & contraction of the wood. This is due to varying humidity during the floor’s life and the conditions at the time of the install. Nail holes are very common in older floors and are usually the result of carpet tack strip, joist nailing to help reduce squeaking, carpet pad staples or runner nails.

Products exist that are designed to fill gaps or nail holes but they are generally only used with new installations on raw wood but we generally do not fill gaps in existing floors. Gaps are a very typical feature with old floors, especially Maple. As the floor ages, the wood tends to dry and shrink in the winter, exposing gaps, and then expand in the summer with more humid conditions. Over time the floor establishes gaps that are permanent. It's a natural side effect of an non-synthetic product like lumber. Moreover, if you look closely at the gaps in your floor, often times there is old finish that has already "filled" the gaps. Because we can't sand out the finish that has seeped into these areas, it prevents putties or filler from adhering well, allowing it to crack out over time.

The best way to control cracks is to control the humidity in the home.

Nail holes often permeate the entire depth of the lumber and then, over time, oxidize and turn black due to moisture. Unfortunately they do not sand out. We generally don’t fill these because our fills are designed to match the wood, not a black stain. Our fills tend to look like white dots surrounded by black rings and are considered less unsightly than the original holes. If filling the holes are something that are critical to your satisfaction with the floor, please let us know ahead of time and we can discuss board replacement. Water based finish can sometimes react to nail heads in the floor, also turning them a black. This can mix with the finish and streak. This is more likely to happen with older, thin floors. It can also happen near the edges where the wood has been face nailed.

Issues when adding new floor to existing floors.

We are often asked to “tooth” new wood into an existing floor that has gaps. It’s important to note that when adding new lumber to these floors, we’ll need to maintain that gapping into the new floor. If not, the new wood becomes out of alignment with the existing material and begins to curve. It is generally not advisable to fill the gaps in the new or existing floor as it tends too look unnatural and crack out over time.

Gapped floors with no substrate

Some floors are installed directly over the joists and have no substrate. This can also be an issue because when coatings area applied, they can seep through to the rooms below. Site protection such as plastic or tarping can be added for an additional charge.