There is a split developing in our linoleum floor right in the doorway to our mudroom (aka: Laundry Room) that I need to deal with before it gets worse.

The house is about 35 years old and I'm pretty sure the linoleum here is original. It certainly predates our ownership, and we've been here 22 years. We added hardwood to the hallway about 10 years ago and ended the hardwood here at the door to the laundry room. It turns out that there is a seam in the linoleum about 2 inches PAST the end of the hardwood, and the linoleum has started to open up and split at that point.

Here is a close-up look at part of the problem area. This is just going to get worse. In fact, if you look in the bottom-right corner of the photo you can see that the linoleum is also failing right at the edge of the hardwood threshold.

I know that ideally, we should just rip out and replace the linoleum floor. That is, however, quite a large job that we just don't want to tackle right now. (Currently it is December of 2020. I'd rather face something like this during the spring or summer of a nice calm year.) For one thing, both the washer and dryer would need to be removed from the room, so that the flooring can be replaced under them as well, but also there is the laundry sink which needs to have flooring under it as well, which means working with plumbing.

Instead, I realized that this flaw in the floor was ideally placed right near the hardwood. If I could just extend the hardwood threshold a bit, I could cover over that crack. Sure, it would need to protrude 3/8" or 1/2" into the laundry room, but that will not bother anyone. So I started thinking about milling up some oak, and if I even had any oak in my workshop right now. But then I had another realization. We naturally saved all the leftover hardwood flooring 10 years ago, so I went down and found the box hiding behind the furnace and dug through it and found this lovely 30" long piece of oak flooring. All I have to do is remove the threshold, fit in this piece of flooring, and then add back the threshold, and that should cover the crack.

First step was to remove the threshold. I used stainless steel screws to fasten it down, so those are still in perfect shape after 10 years.

(Next two photos). I was having trouble removing the threshold, and realized that I had to remove, or at least loosen, the two door stops from the door jam, as they were tightly holding down the threshold. I loosened them enough to be able to flex them inward and upward, which gave enough space to be able to remove the old threshold.

Here I placed the new board together with the threshold and am holding them up to see how they will nicely cover over the crack/separation in the linoleum.

I took them down to the shop and used the threshold to mark off on the new board how long it had to be and cut it to match.

While attempting to test fit in the new board, I realized that I could not just have this flooring extend over the linoleum. I need to cut out at least a part of the old linoleum and underlayment (underlay is 1/4" plywood that is usually placed under linoleum and similar flooring). I used a straightedge and very sharp utility knife to cut through the old linoleum and peel it back.

(Next photos) I then used an Oscillating multi-tool to carefully cut through the underlayment along that line that I had cut with the utility knife. I strongly suggest using an oscillating multi-tool to help cut back the underlay. You could try to do it with another tool, but this one just makes the job so much easier. These tools have really dropped in price over the past 10 years and are now very common. As a hobbyist/homeowner you don't need a super expensive one, but when you need to make a plung cut like this, or when you need to undercut some door trim or the like, it really does the job.

I then could use a prybar to pry out the underlayment, and thoroughly vacuumed out the area to clean it up.

I then test-fit in the new piece of flooring, as well as the old threshold (next photo) I used a scrap of flooring to fit over the tongue of the flooring board and used a hammer to tap it into place so that it in turn fit over the tongue of the neighbouring board. (Apologies for the dark and fuzzy photo -- I was taking pictures from the mudroom and the lighting was partially blocked.)

With the new board tightly seated in place I next fastened it down. I nailed 2" brad nails - 18 gauge -- on a 45-degree angle through the tongue of the new board and into the floor.

Here I'm showing how the threshold still will sit ON the linoleum. It will overhang the linoleum floor by about 3/8 of an inch. This does lift up the front of the threshold, but as the threshold itself is an angled piece, it okay. It still angles down toward the mudroom, just not as mush. Hopefully this helps pin down the linoleum so it doesn't lift up there.

The second last step is to fasten down the threshold, again with those same stainless steel screws.

Here is a look at the finished patch job. I'm very happy with the results. The damaged section of the linoleum is gone, and the flooring looks like it's always been there. Yes, it does now protrude maybe 1/2" into the laundry room, but that is a minor thing that will virtually never be noticed.

Yes the linoleum really is due to be replaced soon, just not now. It is nice to be able to do work when you want to, as opposed to having a job forced upon you. I think this will function well for perhaps as long as a few years.

One final step will be to run a thin bead of caulking along the bottom front edge of that oak threshold. This will help seal the two pieces together and will also prevent any water (from dirty footwear in the mudroom) from seeping under the wooden hardwood flooring.

This entire fix was completed in a few hours in an evening, even with pausing to film.