PSA: My underlayment knife snapped on a glue-down job yesterday

I was about halfway through spreading adhesive for a 500 square foot vinyl plank install when the blade just broke off at the handle. It was a cheap one I grabbed from a big box store maybe two years back. I had to run to my truck and use my utility knife to finish the spread, which was way slower and left ridges. Has anyone found a specific brand of underlayment knife that holds up better to heavy use?

3 comments

3 Comments

wren_rodriguez20d ago

My old Marshalltown knife lasted eight years before it gave out.

seth_carr5d ago

Yeah, gotta disagree with the idea that eight years is a fluke or just good care. @wren_rodriguez's story lines up with what I've seen. Those Marshalltown knives are built for real job site abuse, not just light work. I've watched guys use them to scrape up tile mastic or pop trim loose, stuff that would snap a cheaper blade. The steel holds an edge way longer too. When a tool lasts that long through daily use, it's a sign of good design, not just luck.

hernandez.gavin20d ago

Honestly those cheap knives are fine if you treat them right. A two year run for a tool that costs basically nothing is pretty good. The problem is probably putting too much pressure on it or prying something. A utility knife backup is smart, but blaming the tool feels off. Sometimes we just get a bad day and a blade snaps, it doesn't mean the brand is junk.