What are these diagonal boards for?

[Cheers!]

Hi Garage Journal members,

I'm a long time reader first time poster. I have a question with regards to my garage.

My home is a 1958 home in Northern California; the house is a hip roof style construction with stucco exterior.

My question is what are these two diagonal boards' purpose that connect the left and right garage walls with the front garage wall?

The boards measure 3/4" thick, ~120inches long

Nailed to the top plate of the front and left/right walls with 3 nails at each connection, and nailed to the underside of a joist that span's the left and right wall (it's a 2x6). So the board actually bows because it goes under the joist, and the joist is fastened to the top plate.

Is it for windsheer? earthquake sheer? The house originaly was cedar shingles with slats. But has been redone in the early 2000s with plywood roof decking and asphalt shingles. I'd think the plywood decking is now handling most of the sheer load?

Can I remove these two 3/4" thick, ~120 inch long boards?

Thanks,
Jason

 

[theoldwizard1]

Likely for wind shear. Also likely behind the drywall in the corners.

 

[Cheers!]

corners are empty. They are just 2x4s. I had them open when I was fixing the drywall earlier.

Will a 3/4" thick board that spans over 120" actually help with wind sheer?

I'm thinking these boards were left as part of the original framing to help keep the walls square and never removed. But I could be entirely wrong about this.

 

[Wrench97]

It's bracing, it may or may not be required for seismic in CA.

 

[pattenp]

Is the roof sheathed with plywood or individual 1X6 boards?

 

[chamoisfive]

Required for bracing. Usually for light framed structures such as garages/sheds. Remove them at your peril

 

[Cheers!]

The roof is OSB over the 1x6. I think 1/2" thick but I could be wrong.

 

[turbowoodworker]

I’ve seen those a lot in older homes of that type of construction. Light, and probably ineffective bracing. But they way predate seismic CA codes.

 

[Cheers!]

It's bracing, it may or may not be required for seismic in CA.

I too was thinking the same. Either seismic or wind sheer. But the boards are 3/4" x 5.5" wide [1x6]. How much can these flimsy boards take? I can understand if they were 2x6s or even a 2x4s.

 

[Cheers!]

I’ve seen those a lot in older homes of that type of construction. Light, and probably ineffective bracing. But they way predate seismic CA codes.

The house survived the The Loma Prieta earthquake October 17, 1989, magnitude 6.9 I think unharmed. It was only 24 miles (38km) away.

I bought the house from the original owners that built it in 1958 and subsequently did no renovations since it was built. Intact with the original single pane aluminum windows, original fabric insulated wiring, and the cast iron sewage runs. I ended up gutting the entire house to the studs and rebuilt it with modern everything, but the structure stayed the same.

 

[Wrench97]

Don't forget that with the door open the wind blows in, so the boards would be in tension not compression.

 

[Renegade1LI]

Probably bracing left in by the builder, see it a lot.

 

[wrenchguy]

Bracing so to hold square and plumb + allow the framers to walk top plates without wiggly walls. Done nowadays to a extent but usually removed after everything sheeted.

 

[nadogail]

IMHO, the braces are for shear and racking. I am sure that they will not be approved for new construction.

 

[pattenp]

The roof is OSB over the 1x6. I think 1/2" thick but I could be wrong.

I should have totally read your post, didn't catch the added plywood decking in first post. Since the sheathing has been added the cross bracing can be removed. The original roof construction type required the bracing.

 

[Cheers!]

Thanks everyone! will be taking it out. Don't worry I fully understand the YMMV and this is an internet forum, and the comments expressed are opinions only.

I will be keep the board though, it's a 120"+ long, it is redwood, and not a single knot.

 

[manwithtools]

I should have totally read your post, didn't catch the added plywood decking in first post. Since the sheathing has been added the cross bracing can be removed. The original roof construction type required the bracing.

I'd argue it doesn't mater either way. The original 1x 6 decking was nailed with at least two and probably three nails into each rafter. It's hip roof construction and the roof acts as a frame to prevent racking once fully constructed. Those diagonal braces were to hold the walls square during construction and perhaps thought to add to racking resistance. They contribute very little, if anything once the roof is installed.

 

[Renegade1LI]

Before plywood 1 x 6 cedar t & g was used for sheathing, had to square & brace to hold it, with plywood you don't have that problem.

 

[wrenchguy]

IMHO, the braces are for shear and racking. I am sure that they will not be approved for new construction.

Temporary bracing needs inspection and approval to build a house or garage there today?

 

[The Cobbler]

IMO, I don't think a the time of construction they were considered temporary. they were there to help with shear and racking because of the boards used in construction, now a days a lot of shear is obtained with with sheet goods.