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redhillbob
Finishing Nails

Getting ready to put my moldings back on after installing laminate flooring, I noticed they have anywhere from 2"-3 1/2" nails for nail guns but not sure what size the old nails were. What is the standard size finishing nail to use for this type of job.

dcalabro
Re: Finishing Nails

It mainly depends on the thickness of the material you are working with. I think the general rule is the nail should be 3 times the thickness of the material to allow for the nail to be 2/3 of holding power into whatever the substrate is. So 1/2" you might want 1-1/2" to 2" Also keeping in mind bigger is not always better. If you have very small quarter round, you wouldn't want to use nails so large that it would split.

A. Spruce
Re: Finishing Nails
dcalabro wrote:

It mainly depends on the thickness of the material you are working with. I think the general rule is the nail should be 3 times the thickness of the material to allow for the nail to be 2/3 of holding power into whatever the substrate is. So 1/2" you might want 1-1/2" to 2" Also keeping in mind bigger is not always better. If you have very small quarter round, you wouldn't want to use nails so large that it would split.

As I mentioned in my original post, the rule of thumb is that the fastener needs to penetrate into solid substrate at least the thickness of the material being fastened. That would mean that a 1/2" thick baseboard would need a nail long enough to penetrate the baseboard, the drywall (1/2" - 5/8" ), and then into the wood framing of at least 1/2", totaling 1-1/2".

You are correct in smaller moldings needing less holding power and the dangers of splitting such moldings with larger and longer nails. In cases such as this I am inclined to use a smaller gauge nail and maintain the length necessary for good purchase into solid substrate.

I will note that there are some cases where a solid substrate can't be found, in such cases, driving the nails next to and opposing each other at roughly a 45* angle to the face of the trim will secure it to the drywall. Caulk will not only help to cover minor gaps, but also help to "glue" the trim to the wall.

jkirk
Re: Finishing Nails

for baseboards i use a 16 gauge nailer with 2"| nails, they have more holding power than a 18 gauge plus the gun is more powerful which means it can sink in thicker mdf or hardwoods used, for thin moldings or 1/4 round i use a 18 gauge nailer.

as spruce mentiond the stitch techique works great when you can only shoot to drywall, i have to do this all the time on steel stud framed walls or icf walls. when i do this i always use construction adhesive or atleast wood glue in combination with 3 nails per fastening point.. painters hate having to fill the extra holes but i simply tell them " you can fill the extra holes now or have to come back in 6 months to recaulk everything to the wall when it pulls away

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