I’m in the middle of framing a two story house, currently I have the first floor deck framed, while I attained a high level of accuracy in some areas (level within 1/16″ over 36′), I made some mistakes elsewhere…
Was wondering just how big of a problem are these, from the perspective of professional framers.
1. Mudsill and Rim board/Knee wall are not completely flush: some segments of the mudsill sit inward about 1/8″, other places protruding 1/16″ out, this was due to the mudsill not being fully lined up with the chalkline (inaccurate bolt hole locations) and perhaps bowing of the sill material itself after rainfall.
2. Rim Board not straight: The bottom of the rim board was toenailed to a chalkline, then the floor joists were butted(using open web) to it. I simply end nailed it to the top and bottom flange, didn’t pay attention to the squareness of the joist’s end, since I assumed the factory edge is good. As a result, the rim board slants outwards by over 1/16″ in a few spots.
3. Knee wall not straight: I failed to brace the 11 7/8″ knee wall fully straight before putting on the floor sheathing, now that I’m beginning wall layout I discovered that one spot bows out by 3/16″…
Since I want the wall sheathing to extend all the way down to the mudsill, tying everything together, would the fact that the wall’s bottom sill, the rim board/knee wall/ and mudsill are not on the same plane be an issue?
What are the tolerance values when it comes to these unwanted offsets, I imagine that they’re not entirely uncommon, in my case are things looking really bad or within an acceptable range?
I appreciate any comments on this, as I haven’t found anything else that addresses this issue.
Replies
“Perfect is close enough for this job”
Something that was mentioned on my first framing job by the crew leader.
Personally I’d have to look at what you’ve got started. In many cases things don’t show when finished. In some cases, a little here, a little there magnifies as you go up. Plumb level and square at the start are easy to to build on. And don’t assume anything from the yard is square and the length as ordered......
Another quote I picked up many yrs ago.
“The two things dearest in life are the tools of the trade and the darling wife.
Don’t ask to borrow my tools and I won’t ask to borrow your wife”.
Thanks for replying calvin, appreciate the wise quotes, words to live by :)
Good advice on double checking factory edges, prior to this I knew that the length is not to be trusted, but didn't bother looking at squareness, particularly when one end of the open joist I'm using is not trimmable. I'm rather skeptical that production framers would square up one end of each floor joist, whether it be TJI or other types, before putting them in place. But it seems that in order for the rim to sit perpendicular this step is a must.
I think one of the reasons why additional error has been created is because of the rain. All the members have grown to some extent, including the OSB rim, which increased lengthwise by 1/8". 2x6s which were 5 1/2 become 5 9/16 after heavy rain, adding 1/8" to the width of the building in total. It seems to me that when I layout for the building dimension I ought to make everything smaller by 1/8 to accommodate for the inevitable growth of wood...
1/16th of an inch even 1/8th is not going to wreck your work. Just be careful when 1/16th is measured at the base which then grows to 1/4" at the end of a member...
General rule is to get as close as reasonably possible. The general consensus among the industry is that within 1/4” is acceptable, but it’s kind of a common sense approach as well. Example, a 16’ tall wall within 1/4” from top to bottom isn’t bad, but a 3’ knee wall 1/4” out is a bit sloppy. If you are concerned about being 1/8” off I’m sure your framing is just fine as you are probably doing a good job. Do always need to remember that you are not building a fine Swiss watch, wood is a natural product. It’s not uncommon for studs to twist, shrink and bow 1/4”, perfection is unattainable, but you can get close.
Thank you both for your replies, it's comforting to know that I'm not off by too much. As someone who seeks perfection in most things, working on rough framing is hardly pleasing to me, especially when I haven't quite mastered the skill of controlling error, hopefully after building this house I'll know better.
Though I want to make an attempt to correct places that have gone out more than 1/8" such as the knee wall, for the other members I'll have to live with it.
If I hadn't used adhesive for the subfloor it would be less of a hassle, simply a matter of removing the screws (thankfully I didn't use nails) and pulling the wall back in, with the glue in place it'll take more effort, possibly hitting it with a sledge hammer will knock it loose... I'll post back about how things go if I get a chance.