DIYbanter - View Single Post - Screws are NOT made for Structural Construction

Red Green

"Bob F" wrote in :

wrote:
Years ago, I build a large wall out of 2x4s and fastened them
together with those black drywall screws. (About 3 inch long). I
built it on the ground, and when it was complete, I began to lift it
into place, like I had always dont with walls that I formerly put
together with nails. Well, when lifting the wall, it flexed, and
seconds later I had a pile of 2x4s laying all around me and several
that were resting on top of my body. I quickly learned (the hard
way), that those screws are NOT made for Structural Construction.
They are very brittle and break as soon as they are stressed (such as
lifting the wall in place).

After cussing a lot, I had to rebuild that entire wall, using nails.
I have stuck with nails ever since. Over the years I've been
reminded about NOT using those black screws for Structural
Construction, while having to repair things built by other people who
used them. In fact I bought a shed that was for sale and needed to
be moved. I was preparing to move the shed, jacking it up, when the
shed walls began coming off the shed floor. Sure enough, the builder
had used those damn screws to attach the walls to the floor. We had
to add lots of nails before moving the shed, or it would have been in
pieces real soon.

Anyhow, recently my neighbor built a fairly large canopy to put over
his door, and prebuilt the whole thing on the ground, complete with
steel roofing. He got it done, and found it was too heavy for two
men to lift above his door. So, he came to me, knowing I have a
tractor with a loader. I took the tractor and lifted it above his
door. He shot several of those gold colored deck screws into the
house, and propped some 2x4's under it until the permanent posts
could be placed. I lowered the tractor loader about 6 inches as the
guys tried to raise the front edge of that canopy with the prop 2x4s
because the front was too low.

It was fortunate I had not removed the tractor loader, or someone
could have been hurt, not to mention damage to the canopy, because it
fell right off the house wall. The cause was those deck screws
snapped.

I was a little surprised myself. I thought deck screws were stronger
than those black drywall screws. I guess I was wrong. While they
probably are somewhat stronger, they are still brittle and they will
break.

We got it back in place, but used 16D common nails the next time and
everything worked perfectly. After that incident, I've pretty much
come to the conclusion that Screws are NOT made for Structural
Construction. None of them. Nails may bend, but still hold the
boards together. But screws break, and when they break, the boards
do not stay together. In fact, they're dangerous.

Unless they make a screw specifically for structural construction,
(which I am not aware of), I dont recommend using screws for any
structural construction at all. Stick with nails.

There are plenty of screws that are strong. Drywall screws and deck
screws are not among them. The are made or hard brittle metal to
resist the force of screwing them in, and are too thin to have any
real strength. They often break just screwing them in or out. Look at
the thickness of the screw center shaft, ignoring the threads. There's
almost nothing there. Try bending them and see what happens.

Try cutting one with a hack saw. Too hard=too brittle=to snap. They are
DRYWALL screws.

I dont recommend using screws for any
structural construction at all.

And if someone has their underlayment nails popping through the vinyl
because they didn't use ring shanks then that means all nails are no good
for anything?

And if someone has a bunch or drywall nail pops because regular nails
were were used vs drywall nails then the nails that were used are no good
for anything. [Yea I know. Who uses drywall nails any more?]

These nails & screws didn't get put in by themself. They were chosen and
put in by someone, a person, "who knew what they were doing".