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A friend used trim head screws for ALL of the 2x4 framing (including the outer walls) of his 2400 sq. ft. house. The house uses 8x8s to carry the load; none of the 2x4 framing is load bearing. The inspector did not see a problem with it (but maybe she didn't even see the screws).

Edit- the picture below shows a similar (post and beam) style of building. The original building was a wood/furniture shop (not commercial); it was erected about 20 years ago (±5 years). The old exterior walls were removed (I don't know anything about them); the new walls are 2x4 construction with trim head screws, including the exterior walls. The friend is a maintenance guy... not an engineer.

Is it built to code? Would it be correct to assume that (at least) the outer walls are in danger of windy conditions and earthquakes?

enter image description here

Ben Welborn
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    Where is the home that 2x4 exterior walls meet code? Questions about legality must necessarily mention jurisdiction. – isherwood Apr 05 '16 at 19:10
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    In my experience, screws of this type are very hard (to retain integrity while driven) and therefore somewhat brittle. They're much more likely to crack under shear stress or from repeated bending than wire nails. Subscribing. – isherwood Apr 05 '16 at 19:14
  • @isherwood I would be suprised to find where it meets any building code. But he's in Virginia. I told him that screws were brittle, and he agreed, but said it was easier than nailing and cheaper than a nail gun (and compressor). – Ben Welborn Apr 05 '16 at 19:22
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    If he was trying to avoid costs, why not just use Elmer's paper glue? Those nails cost a lot more than simple glue. ;-) – wallyk Apr 05 '16 at 19:25
  • @isherwood According to IRC Table R602.3(5), 2x4s are still allowed for one and two story homes. – Tester101 Apr 05 '16 at 20:01
  • @wallyk Don't laugh, use West System epoxy. Bit of fiberglass in the fillets, you will not get that house apart... – Harper - Reinstate Monica Apr 05 '16 at 20:31
  • @harper Well if trim screws are ok, I suppose glue is also legal for interior framing. – Ben Welborn Apr 05 '16 at 20:39
  • @tester101 can you weigh in on glue for interior framing? – Ben Welborn Apr 05 '16 at 20:41
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    They're not structural screws and therefore do not meet the requirements as replacement for 16d nails. 16d nails will bend when house framing is subjected to earthquake, non-structural screws can snap off, causing join failures. This however sounds like it's a post and beam construction house. – Fiasco Labs Apr 05 '16 at 20:55
  • @FiascoLabs Yep, 8x8 posts and beams and buttresses. What does that mean for the new outside (2x4) walls? Can he glue them? – Ben Welborn Apr 05 '16 at 21:27
  • @BenWelborn If they are interior non-bearing walls, then maybe you could get an engineer to design a wall using glue. I doubt it would pass without an engineer's stamp, but stranger things have happened. In a seismic area, it would likely never fly. Exterior walls are a bit different, since they have to deal with wind loads. Even when they're not bearing, they have to be built to withstand that. – Tester101 Apr 05 '16 at 21:49

4 Answers4

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According to Table R602.3(1) of the International residential code (IRC), you have to use two 16d (3 1/2" x 0.135") fasteners to end nail the top or sole plate to a stud. If the studs were toe nailed to the sole plate, then either three 8d (2 1/2" x 0.133") or two 16d (3 1/2" x 0.135") fasteners would be required.

International Residential Code 2012

Chapter 6 Wall Construction

Section R602 Wood Wall Framing

R602.3 Design and construction. Exterior walls of wood-frame construction shall be designed and constructed in accordance with the provisions of this chapter and Figures R602.3(1) and R602.3(2) or in accordance with AF&PA’s NDS. Components of exterior walls shall be fastened in accordance with Tables R602.3(1) through R602.3(4)...

Table R602.3(1)

If by some chance these screws are equivalent to 16d nails, then they should be acceptable. However, I doubt they're equivalent, and therefore should not be used.

There's no specific fastener schedule for interior nonbearing walls, while interior load-bearing walls are required to be framed the same as exterior walls.

R602.4 Interior load-bearing walls. Interior load-bearing walls shall be constructed, framed and fireblocked as specified for exterior walls.

R602.5 Interior nonbearing walls. Interior nonbearing walls shall be permitted to be constructed with 2 inch by 3 inch (51 mm by 76 mm) studs spaced 24 inches (610 mm) on center or, when not part of a braced wall line, 2 inch by 4 inch (51 mm by 102 mm) flat studs spaced at 16 inches (406 mm) on center. Interior nonbearing walls shall be capped with at least a single top plate. Interior nonbearing walls shall be fireblocked in accordance with Section R602.8.

Tester101
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  • Hmmm... end nail the top or sole plate to a stud. I'll ask him next time I see him... but obviously I couldn't verify it without pulling the wall down to see it, but I'm gonna say that I saw some toe-screwing. – Ben Welborn Apr 05 '16 at 20:00
  • The row above that one lists toe nailing studs, but only to the sole plate. That table also mentions built up headers, abutting studs at corners, studs to sole plate, etc. All of it calls for nails, mostly 16d. Though I wonder if timber framing means these walls have different code, as they aren't load bearing. But since they're exterior, they do take wind load. – Tim B Apr 05 '16 at 20:00
  • I suppose that for interior walls it's fine. – Ben Welborn Apr 05 '16 at 20:04
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    Consider the screw thread. Does it have good bite into both pieces being attached? – Harper - Reinstate Monica Apr 05 '16 at 20:32
  • Yeah the trim screws were all sunk about 1/4 inch into the studs (making them a little harder to notice. So, in essence, he built it to code inside- single top plate and fireblocks; if he says he used nails on the outer wall (where they can't be seen anymore) then he can pass inspection. No fear of big bads wolves. – Ben Welborn Apr 05 '16 at 20:36
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    I would not be so quick to leap to this conclusion. If the exterior walls are not load bearing and there are 8x8 posts used for the structure it's not clear to me that section R602 is even applicable. This is clearly not a "regular" wood-framed house... maybe it's heavy timber construction, maybe something else. Also it is certainly possible for a screw to be designed to have the same shear strength as a nail. Did the builder just pull something off the shelf at Home Depot or was it spec'd by the engineer? We don't know. – Hank Apr 05 '16 at 20:52
  • @HenryJackson The screws are definitely off the shelf. The load bearing frame (8x8 square timber) was built by a previous owner; this building is being converted from a furniture shop (previous owner). The new owner (my friend), threw up new walls (inside and out) in a couple weeks. – Ben Welborn Apr 05 '16 at 21:01
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    @BenWelborn: OK well if this is a commercial structure than residential building codes do not apply, you would want to look at the IBC. But the fact remains that you have not really established whether this is a "wood framed structure" or just a building that has some wood in the exterior wall. – Hank Apr 05 '16 at 21:11
  • @HenryJackson this WAS a wood shop; I don't think it was "commercial"... but it looks well built (I didn't see the old exterior walls). Are you saying that 8x8's are not technically a wood-frame construction, and that perhaps "timber-frames" have different codes relating to the exterior wall? I can say that the new exterior 2x4 walls are not actually load bearing (I don't remember if my friend put a double top plate on them, but the 8x8 frame is definitely stout enough- without need of the new exterior walls for support). – Ben Welborn Apr 05 '16 at 21:20
  • @HenryJackson If this is a true post and beam construction, then this code section does not apply. However, if it was post and beam construction, why would they be building 2x4 exterior walls? Since the walls are exterior, and are wood framed, I'd say the code applies. Of course if there are approved engineer plans, those trump everything. – Tester101 Apr 05 '16 at 21:43
  • @Tester101: well to be more general, if the building is anything other than platform or ballon light framing, section R602 doesn't apply and the structure needs to be designed by an engineer. Maybe the owner is just using 2x4s as cladding and to hang drywall from? It's not clear to me. – Hank Apr 05 '16 at 21:51
  • @HenryJackson I disagree. The section is not "*Wood Wall Framing in platform or balloon framed structures*". Section R602 applies to any wood framed wall (a wall made up of studs and a top and sole plate), not just those that are part of a specific overall framing method. In either case, an exterior wall has to stand up to wind loads, and should be built to the minimum code standard to do so (in my opinion). – Tester101 Apr 05 '16 at 21:59
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    @Tester101: R301.1.2 says: "The requirements of this code are based on platform and balloon-frame construction for light-frame buildings. [...] Other framing systems must have equivalent detailing to ensure force transfer, continuity and compatible deformations." The specific design criteria are given in the rest of R301 that an engineer may use to design the structure. – Hank Apr 05 '16 at 22:02
  • @HenryJackson I agree, if there are engineer plans, those should be followed. Otherwise you should build a framed wall to minimum code standards, which is two 16d nails. – Tester101 Apr 05 '16 at 22:44
  • This bit about interior nonbearing walls is beautiful. I'm working on a couple non-structural framing applications in my basement that are simply easier to construct using my pocket-hole jig due to the locations I need to join 2x4s to each other. I would not be able to do some of what I need to with a framing nailer. Also, in limited applications, I find stick framing (nonbearing walls) with pocket holes to be easier for someone like me who doesn't have the skill to toe-nail consistently well with a framing nailer. – MuffinTheMan Sep 28 '16 at 02:56
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You have a complicated question here and the best (and most legally-correct) answer will probably come from talking to your local building inspector. Preferably before a lot of work has already been done...

First, the question of which building code is even applicable is not clear to me. The International Residential Code ("IRC") only applies for 1- and 2-family homes, but this sounds like maybe it is a commercial structure in which case the International Building Code ("IBC") would apply. The exact version and any local amendments (which can be significant, by the way) would depend on your specific location.

The IRC does provide some pre-computed nailing patterns for wood-framed that Tester101 has quoted, but those only apply to light-framed platform or balloon-framed structures (see R301.1.2). It sounds like this structure is probably not that, since you have heavy timber columns. It could be post-and-beam or some other construction technique. In which case the structure needs to be designed by an engineer. (Or maybe the heavy timber is just decorative?)

Finally, screws can be used for structural purposes but they must be designed as such. If you are straying outside the prescriptions of the building code you need to have an engineer do the design first.

Hank
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  • I didn't talk to the building inspector. The only time I have seen the house was last Sunday. I would not frame a house (inside or out) with screws! This was never a commercial building. It is a 2400 sq. ft. (two story) single family home now (or it will be, very soon). Yes, it is a post and beam house. 8x8s are the only structural support. All of the 2x4 walls were added about a week ago... converting an old post and beam wood shop (originally built about 15-25 years ago- I would guess) into a home. The new 2x4 walls support nothing but themselves and some windows. – Ben Welborn Apr 06 '16 at 12:24
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Just found this.

The SDWS Framing screw is designed and load-rated for replacing 16d, 10d and 8d nails in framing applications. The SDWS Framing screw is 0.160" in diameter and superior to nails in holding power and pull-out resistance. It is code listed under IAPMO UES ER-192 and meets 2012 and 2015 IRC® and IBC® code requirements for several common wood framing applications.

https://www.strongtie.com/strongdrive_exteriorwoodscrews/sdws-q_screw/p/strong-drive-sdws-framing-screw

Kidd
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Going to necro this post because there is no definitive answer after 6 years and 61k views

This line in the question and the picture says it all,

"The house uses 8x8s to carry the load; none of the 2x4 framing is load bearing"

This picture is a wood peg post frame building all the structural strength is there, if there was red vertical siding on the outside it would be called a barn.

Adding 2x4 framing between the outer side of the posts would just increase the strength and prevent racking of the posts, basically it would be built better than a brick sh*thouse.

While the heads on the screws aren't the best for the application the 2x4 walls would need to deal more with strain from the weight of the siding/stucco on the outside of the walls than holding up the building.

Basically it would have to rip a screw through the 2x4 sideways or snap them all from the weight of a 6' to 8' section of siding and drywall.

As long as he used enough screws to hold the walls up its just fine

Leo Denny
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    This does not provide an answer to the question. Once you have sufficient [reputation](https://diy.stackexchange.com/help/whats-reputation) you will be able to [comment on any post](https://diy.stackexchange.com/help/privileges/comment); instead, [provide answers that don't require clarification from the asker](https://meta.stackexchange.com/questions/214173/why-do-i-need-50-reputation-to-comment-what-can-i-do-instead). - [From Review](/review/late-answers/144796) – JACK Apr 18 '22 at 00:39
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    Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – gnicko Apr 18 '22 at 00:41
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    Somehow [the accepted answer](https://diy.stackexchange.com/a/88123/34147) from 6 years ago that references the IRC isn't definitive? If you've got something from a code source that contradicts that answer (or an update to code), then please feel free to [edit] it in to your answer. If not, then this really reeks of "some guy on the internet says"... – FreeMan Apr 18 '22 at 13:11
  • This answer verifiably correct. Go and ask any structural engineer, since the structure is 8x8's, the walls are not considered exterior walls, which the IRC deem them to be ONLY if they are structural. The building in question was must have been approved by a structural engineer and can have anything from 2x6's to SIPs (which have significantly less strength than a 2x4) to fill in the voids. – cyanrarroll Feb 09 '23 at 04:44