# 1x4 Let-In Diagonal Bracing Alternatives



## HandymanDHW (Aug 31, 2016)

Hi All, 

I have a question regarding the use of 1x4 lumber as diagonal bracing to prevent racking in un-sheathed walls.

It appears that in the building code, when a wall is unsheathed (i.e. uses no plywood or uses non structural sheathing such as foam insulation) then diagonal bracing is required to resist racking from wind forces.

The prescriptive bracing method is to use 1x4 lumber extending in a diagonal line from top to bottom plates, at an angle between 45 and 60 degrees from horizontal. The code lists requirements for the number, size and placement of nails as well but it escapes my mind right now. Also, the standard way of installing the bracing is within a channel cut into the studs so that the bracing and stud faces are flush, making it easier to install drywall or foam sheathing on top.

I'm building a super-insulated house with an exterior wall system consisting of two parallel 2x4 stud walls with a 5" gap in between for a full cavity thickness of 12". The outside wall will be sheathed with plywood on the exterior so racking is not a concern but the inside wall will only have drywall on the interior. It will be independent from the outside wall and won't have any structural components to resist racking... unless I install 1x4 diagonal bracing. A g to put it would be on the outside of the interior wall... within the 5" gap between the two walls. Because there's no paneling going in there, I wouldn't necessary need to bother with notching the studs and installing the bracing flush... I could just nail it directly to the faces of the studs.

Provided I followed all the other code requirements and only ignored the part where the bracing is actually recessed into the studs, do you think that would be okay?

There is no official adoption of the building code where I live and no inspectors. It's completely up to me to make sure my house is structurally sound.

Thanks.


----------



## Msradell (Sep 1, 2011)

I really wonder if you need bracing and the inner wall since the outer wall will be braced with plywood. I really don't see how it could rack. However if you think it's necessary I don't see anything at all wrong with the method you propose. I do have a question about fire blocking however. Have you done any research into how walls built like this are fire blocked? Normally it is very simple by just putting a piece of 2 x 4 or possibly 2 x 6 between adjacent studs. However just doing that would provide fire blocking the type of all your building.


----------



## HandymanDHW (Aug 31, 2016)

Thanks for your reply.

Fire blocking typically isn't used in new houses around here, even in the cities and large towns where there are inspections and strict adherence to the building codes.

The typical method of construction is to use a simple 2x6 studded wall on the exterior, 24" O.C. and to fill the cavities with fiberglass batt insulation with no fire blocks. They are used on interior walls however.

This area has experienced a huge housing boom in the last decade with 1000's of new homes built and I'd be surprised if a single one of them differed even slightly from my description above.

Still, I have thought of fire blocking methods and realized that the blown-in dense pack cellulose I'm using for insulation would suffice. In some areas it's actually an approved fire block.


----------



## SeniorSitizen (Sep 10, 2012)

Google wall strap bracing.


----------



## de-nagorg (Feb 23, 2014)

Senior Sitizen is right, they make a steel strap just for doing what you are proposing. I have used it and like the way it is much easier than 1X4 , and is just as strong and will even allow you to put up sheathing with no trouble as long as you are careful not to try to nail sheathing through it. 

So I too recommend the strapping.


ED


----------



## HandymanDHW (Aug 31, 2016)

Thanks guys for the replies.

I originally wanted to use the steel strap bracing that you propose ( I've always called it "Metal T-Bracing" or L-Bracing") but you can't get it around here.

I'm stuck with conventional dimensional lumber.

I also hear that the metal strapping can't be used a direct substitute for 1x4 and that it needs to be signed off by an engineer... no engineers around here willing to touch a double stud wall either.


----------



## SeniorSitizen (Sep 10, 2012)

QUOTE:There is no official adoption of the building code where I live and no inspectors. It's completely up to me to make sure my house is structurally sound.



I also hear that the metal strapping can't be used a direct substitute for 1x4 and that it needs to be signed off by an engineer... no engineers around here willing to touch a double stud wall either.

*************************************************************
I'm confused and I'm getting accustomed to that, but no codes and no inspectors so why the engineer.


----------



## ddsrph (Nov 23, 2013)

Would it help if one of the top and bottom plates was a two by twelve? This would make it one wall. For the other top and bottom plate side by side two by sixes could be used or if price similar use two by twelve for the two each top and bottom plates.


----------



## Tizzer (Jul 24, 2010)

You don't brace interior walls, that's all this second parallel exterior wall is. Bracing will probably go over where your windows/doors are anyway. You might do something like ddsrph mentioned with a 2X12 top plate or you'll have a 5 inch air gap going up into the roof(or whatever you have going on there).


----------



## Msradell (Sep 1, 2011)

Just wondering where are you located that you don't have codes and inspectors?


----------

