Can I use Deck Screws / Wood Screws for indoor framing?

Question

I am a new DIYers

I built one-room frame using Wood screws 3.5"

Here is its description

https://www.rona.ca/en/product/reliable-fasteners-flat-head-wood-screws-10-x-3-1-2-in-zinc-plated-100-per-pack-square-drive-fkwz10312vp-1399386

I wanted to buy more screws but found there are cheaper ones and called Deck Screws

Here is its description

https://www.amazon.ca/gp/product/B08BS84HVK/ref=ox_sc_act_title_1?smid=AJ579ZVYWDSDG&th=1

now I am confused if I used the wrong screws in the frames I built.

and if I can use the Deck screws in the remaining framing job?

Please advise.

Answer 1

Deck screws, construction screws and wood screws are not rated and not permitted for structural work.

The shear strength of general unrated screws does not suffice to withstand live loads with additional dynamic loading and movement due to wind and earthquakes. Framing nails may bend while construction screws may snap.

There is a use for construction screws in load bearing applications, though, which is to pull lumber tightly together or hold it in place so that it can then be nailed to spec.

If you want to fasten structural members, you should use framing nails or structural / framing screws for framing elements. Here is an example:

For headers, beams, joists and load bearing walls, use the above.

Alternatively use 10d framing nails:

(Building codes specifically mention nail strengths (8d 10d etc..) and nail patterns, and it is up to the manufacturer of screws to rate and test their screws to replace such nails.

The above framing screws are different from construction screws such as this one, which is not rated for structure:

Deck screws are sometimes available at a lower price than wood screws but they are equally not allowed for structural work:

So depending on where you used these screws they may have to be replaced or supplemented.

Do not use wood or construction screws for joist hangers, beams or headers / lintels.

You can use wood & construction screws for fastening windows, doors, strapping, furring, bulkhead boxes etc...

I have seen studs fastened to the plates with wood screws, which I believe is allowed in non load bearing interior walls. In these cases you could use coated wood screws a.k.a deck screws. There's no need for the coating indoor, but sometimes they are cheaper.