I'm building a new home and wanted to be on top of things that may become major issues later on. They just did most of the framing and there are some 2x4s which are visibly bowed as well as floor joists which are bowed as well.

Upstairs I could see light coming through some of the walls that are coming together which was kind of surprising. There were a couple of small gaps between the walls which had light shining through.

I didn't realize they no longer use OSB on the exterior walls and it looks to be some structural insulated sheathing which looks and feels very cheap. I'm not even sure how this will hold the siding on to be honest.

If something were to hit the house it would seem like it would be easy to punch a hole right through this stuff.

Here's the sheathing product they used.

Are any of you familiar with this? I'd like to get your thoughts both on the sheathing, the holes I have found punched through in various parts of the exterior walls and what problems I could be facing with bowed wall studs and floor joists.

I'm not very savvy when it comes to this stuff which is why I come here to ask the experts. I really want to know the right questions to ask my project manager for the house or demand things before I sign off on anything. Thanks!


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    Thermo-Brace appears to be specifically engineered to meet code, but without much of a safety margin. Plus, that's only if you install it properly, and I'm not sure I trust the construction company to do that. What I suggest is that you take pictures. These will be useful reference after you move in, as it lets you know what's under the walls, as well as being potential evidence if it turns out they messed up, as well as being something you can show the project manager, as well as being something you can post here. Commented May 11, 2019 at 20:16

2 Answers 2


You've asked about two distinct things here. I'll address them both, but in the future please ask just one question per post.

First, bowing in lumber is unavoidable. It's a natural product, after all. The question is one of deflection tolerance. My family's company wouldn't use anything that was bowed on the strength axis more than about 1/4" in 8 feet. Even with good culling, it's critical to "crown" all lumber--align the bows to the same direction--to minimize variance from one stud or joist to the next.

Bows on the thickness axis can and should be straightened to a reasonable degree when sheathing is installed. They don't have an impact on strength or rigidity, but unaddressed deflection makes everything more difficult, from drywall installation to cabinet setting.

What your builder considers acceptable is at his/her discretion, and is ultimately up to you and your contract. Bring it up for discussion in a respectful manner if you're not satisfied.

Secondly, gaps in wall sheathing aren't necessarily a concern. Most sheathing specs call for an expansion gap, in fact. If the sheathing has an integrated air/moisture barrier the joints will probably be sealed with specially-made tape anyway. Read the literature for your product and raise any issues with your builder.

As to the holding power of the sheathing for siding fasteners, they'll just need to fasten to studs. Soft sheathings (fiberboard, gypsum) have been used for decades and this is how it's done.

Finally, OSB is still commonly used for exterior wall and roof sheathing. Why your builder is using a different product is another point for discussion. How does it integrate with the rest of the insulation and air barrier plan? What's the final R-value of your walls going to be? I'd have expected that all that would be in your contract and had been discussed before now, but it's better done late than never.


Inspecting / approving your builder’s work may be beyond your capabilities if you lack experience in the building trades. Poor practices could be clearly visible but unseen by you because you just don’t know enough. No disrespect intended – you might be an expert in, say, rocket science, but that doesn’t count for anything when building a home.

Suggestion: Find a local licensed home inspector to examine the builder’s work and advise you. You should budget several visits at critical times in the construction project. The cost per visit should be less than a full home inspection, since the time on site will be short and you don’t need a full written report, just a punch list for the stage of construction just completed.

Do any home inspectors out there agree with me?


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