DIY Home Improvement Forum banner

No sheer strength in Garage walls

1 reading
16K views 39 replies 13 participants last post by  High Gear  
#1 ·
I have a stick built garage in a house I just bought. I was starting to get more and more curious about why the walls feel so flimsy and are so easy to shake. Turns out the 2x4 walls only have siding over them. So they put up the walls, covered in house wrap, and then put up the siding. NO PLYWOOD, NO OSB.

The guy at Lowes said that's why everything feels like it could fall over and you probably could push it over with your car or with a really high wind.

His idea was to rip off external siding and osb the whole garage and then put siding back up or new siding. Or he said put OSB on interior wall that way at least there would be sheer on one side. However that option destroys my 2x4staggered stud wall plans I was going to do. Not enough room on footer for that.

What is the best way to resolve this? Should I just bite the bullet, tear down all the siding and OSB the entitre exterior with screws and then put the hardiboard back up over it?

Isn't normally the process 2x4 framing ----> OSB ----> Tyvek/Typar ---->siding ?
 

Attachments

#5 ·
Yah the pro at lowes mentioned that too. Doing something like an X over several studs. However, if I do that on the inside than I will take up room over the sill plate and not be able to do the staggered stud 2x4 wall on the 2x6 bottom plate. That's why I'm hopefully looking for options that can be done without adding material to the inside.
 
#6 ·
Avadon, how about a picture or two inside and out standing back far enough to see the wall. It appears that your siding is a sheet product. If so then the siding also acts as the sheathing and is pretty common for a detached garage. Not sure what your version of “flimsy and shaking” is but the walls should not be moving based on the detail you show in the picture.
 
#13 ·
Well it just does not feel extremely rigid. Maybe for an attached garage it's pretty common to just use 1/4 siding/sheeting (cementboard) and no OSB first. But i'm turning this into a metal shop and I want really strong construction.

The walls are not moving perse' they are just easy to shake with your hand. I know putting osb on the inside will solve a lot of that but I was planning on a decoupled wall for sound suprression.
 
#7 ·
There may very well be greater issues here. What is your existing siding? I can't tell by the photograph, but it does look like a sheet product which should have a good shear value.

A properly constructed building shouldn't be shaking even without any type of shear panel. My house was built in 1986, and is cedar bevel siding over felt and studs. It has minimal let-in x-bracing, and has withstood earthquakes.

Why do you need staggered studs in a shop? If you are adding thermal or sound insulation, you could achieve the same thing by sheathing the interior with ply and then using foam, or by using 2 x 3 studs on the interior
 
#9 · (Edited)
That is how homes were built in the old days. 2x4 walls, with 1x4 planks either placed horizontal or on a 45 degree angle, then siding placed over that. If the home was built correct, the house was very stiff, and did not flex that much, unlike homes built these days.

My garage is built with metal straps across from the corner to the top plate at a angle, but the outside is covered with "Car Siding". It does not flex, so it sounds like your garage was not built by plans, but sounds more like it was a diy build.
 
#15 ·
Isn't it going to immensely help the overall structure to have OSB over the 2x4's, then house wrap, then the siding? Won't that give me a great deal more mass for sound suppression?

here are more pics. Again I looked at some John Mansville insulation systems and they said for a 2x6 space that 2x4 staggered stud wall offered the best stc value, even better than just doing a 2x6 wall. If you put one layer of 5/8's drywall up it gets better, 2 layers with overlapped seems even better.

Here is the link
http://www.specjm.com/files/pdf/wood_framing.pdf
 

Attachments

#17 ·
What I mean by flimsy, shaky, or not strong is that you can grab a 2x4 about anywhere and start vibrating it hard with your hand and it will shimmer that effect all the way around till the garage doors are shaking. So it's like there is no rigidity in the corners. Any vibration can just carry all around the structure. I mean is there any reason not to take off the siding and put 1/2 or 3/4" OSB all around the outside. Wouldn't this greatly help the mass and strength of the structure? As well as put in some corner bracing?
 
#19 ·
I see no “1/4 siding/sheeting (cementboard)”.

I see nothing out of the ordinary with the construction, not high end either.

You mentioned nothing in your OP about turning this into a stealth fab shop.

I don’t know how you expect to get useful answers with partial and incomplete questions.
 
#21 ·
Ahh yah I mentioned the whole blacksmith/metalshop on other posts. All the exterior paneling on the ATTACHED garage is 1/4 sheet. I think it's some kind of sheeting with cement in it for fire rating.. or something like that. I'm not sure what the correct term is but they got it at lowes for about 23$ a sheet. You can see the place where it isn't painted.. it's that tan stuff.
 
#22 ·
I guess the issue is just that the 1/4" hardiboard siding (or whatever it's called) just doesn't do much of anything for adding a great deal of rigidity to the structure and I need a good bit of exterior rigidity so I can use all of that 2x6 footer for creating as much STC value as I can.
 
#23 ·
Avadon said:
This is not a bad idea. Even some sort of metal bracket that goes over the studs or between them (if I do staggered stud). A bracket or 1x4 that creates a triangle shape in the corner from one wall to another.
Build your staggered wall and put the angled braces in that wall. If you put the braces on the inside of the new wall you can them nail them to the existing wall.
 
#24 ·
It sounds like/looks like the siding is, in fact, a sheet good product. If that the case, and you can grab a stud and shake it, then it sounds like the siding is only fastened at the top and bottom of the studs, maybe even only to the top & bottom plates. Push on the siding at mid-height of the stud. Does the stud push out with it at all? if not, it just sounds like you need to nail it. I can;t give you the exact nailing requirements, but 18" o/c would probably be enough and you can probably get away with just doing the corners. If it's hardi-plank, you may have to pre-drill...not sure.

If that doesn't work, you can try gauge metal straps going from top plate to bottom plate. That would impinge on the interior too much. Make sure you start at a stud location and end at a stud location and try to keep the straps somewhere around 45 degree angle.

As far as the sound goes, try a test if you haven't already. The living room couch in my house is only 15' from the garage door and you can watch TV while I grind or even use a gas-fired welder in the garage. You can still hear it, but it's not as bad as you would think. Now, I have cellulose insulation, which helps, and that may be something you might want to look into, but I would have thought that the noise from the welder would have boomed through the steel entry door, but it didn't. You'll have to determine how much sound is and is not acceptable and proceed accordingly.
 
#25 ·
I'll check today to see of it's nailed enough. I prefer the exterior star drive screws. Expensive but so worth it. All the nails have slightly popped around the garage and most of the house. I would have to imagine that 1/4 sheeting to be a decent fire product/siding product but as far as an only exterior I would have to believe that is minimum code. I watched 5 garage building videos on youtube yesterday and they all went from 2x4 studding to OSB or plywood, and then they Tyvek wrapped and then they went on to whatever their choice of siding was. You must just get a lot more solid exterior doing it this way. And then if you feel you still need something, that metal strapping. Oh Well re-sheeting everything is not the end of the world. I'll just do one wall at a time. I don't know if i'll put the original siding backup or not. I guess it would save me a lot of money and it's already cut to fit.
 
#26 ·
Screws have less capacity than nails, but the loads are small, so screws should be fine. If you are looking for a fire rating you will need to sheetrock the interior. The stud/OSB/tyvek/siding system is typical, but the component that provides any significant lateral stability is the OSB sheet (the siding will provide a little bit of stability, but it would be provided by a combination of the siding and the studs bending and is not something that is worth taking into account). If your siding is, in fact, in sheets, then it should be ok for use as a shear panel. It may only be 1/4" thick, and if you were to start over 1/2" OSB would be the right material to use (with tyvek & siding on top of the OSB). However, a 4'x8' sheet 1/4" thick has substantial shear capacity when compared to the winds loads on your garage. If I am right and the the siding panels are not properly nailed, then you can nail/screw one panel and see how much of a difference it will make.
 
#27 ·
Went a did a more thorough inspection. It's fairly well nailed but certainly not as tight as screws would be. Mostly it's the far wall.. the wall opposite the side that is attached to the house that is weak/flimsy. The footer is bolted down very tight (I tightented those anchors) and I also put lots of screws to make sure the 2x4 footer is extremely well bonded to the 2x6 that sits on the concrete block perimeter. Maybe that wall is just weak because it's the far wall and there is no catwalks across the trusses to connect the side near the house with the side that is furthest from the house?

I think for what I am going to do, taking down the siding and putting up the OSB is the right thing to do. I guess you can't blame people for housewrapping/tvyek the studded wall and then going right to sheeting. After all most people just put cars in their garages so they don't need an industrial structure.

Is there any instructions you know of for putting up OSB. Orientation and what not?

Thanks for the great help! :thumbsup:
 
#28 ·
The siding/sheathing on the garage is rated for shear flow. You are fine in that regards; http://www.apawood.org/level_b.cfm?content=prd_sid_main The 1/4" you are looking at is the under-lap edge of the sheet at the corner, this is normal as it gets it's shear value from the thinnest layer-- under-laps, channel grooves with full thickness of 9/16-5/8". This (full wall) is way more structural than adding any metal straps, flat,or metal let-in braces which are supposedly temporary only. The wood diagonal let-ins meet minimum code but are also weaker than full-wall or just corner panel sheathing; http://bct.nrc.umass.edu/index.php/publications/by-title/insulating-on-the-outside/

To help stop noise, add 3/4" OSB for density after adding rock wool insulation to the cavities- leave no gaps or voids: http://www.diychatroom.com/f98/biggest-loser-fiberglass-insulation-90438/ Use caulking or green glue on all connections for air-tight; http://www.buildingscience.com/docu...ts/information-sheets/4-air-barriers/air-barriers2014airtight-drywall-approach/

The whole wall is shaky- not the studs to sheathing, because the top plate is not anchored to the garage ceiling. Add a 2x4 across the ceiling joists/rafter ties to stabilize it every 4' lineally. BTW- you are lacking lateral resistance (front/back push), not shear (end wall push): http://www.awc.org/pdf/WFCM_90-B-Guide.pdf Notice the nailing spacing, size, etc.

Check your location for wind resistance, if worried or want to exceed minimum Code for your area; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_3_sec001_par004.htm

The orientation of OSB makes no difference for sheathing walls. Remember to leave a gap all around, and with any engineered product- don't get it wet; http://osbguide.tecotested.com/pdfs/en/el812.pdf

Gary
 
#29 ·
The siding/sheathing on the garage is rated for shear flow. You are fine in that regards; http://www.apawood.org/level_b.cfm?content=prd_sid_main The 1/4" you are looking at is the under-lap edge of the sheet at the corner, this is normal as it gets it's shear value from the thinnest layer-- under-laps, channel grooves with full thickness of 9/16-5/8". This (full wall) is way more structural than adding any metal straps, flat,or metal let-in braces which are supposedly temporary only. The wood diagonal let-ins meet minimum code but are also weaker than full-wall or just corner panel sheathing; http://bct.nrc.umass.edu/index.php/publications/by-title/insulating-on-the-outside/

To help stop noise, add 3/4" OSB for density after adding rock wool insulation to the cavities- leave no gaps or voids: http://www.diychatroom.com/f98/biggest-loser-fiberglass-insulation-90438/ Use caulking or green glue on all connections for air-tight; http://www.buildingscience.com/docu...ts/information-sheets/4-air-barriers/air-barriers2014airtight-drywall-approach/

The whole wall is shaky- not the studs to sheathing, because the top plate is not anchored to the garage ceiling. Add a 2x4 across the ceiling joists/rafter ties to stabilize it every 4' lineally. BTW- you are lacking lateral resistance (front/back push), not shear (end wall push): http://www.awc.org/pdf/WFCM_90-B-Guide.pdf Notice the nailing spacing, size, etc.

Check your location for wind resistance, if worried or want to exceed minimum Code for your area; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_3_sec001_par004.htm

The orientation of OSB makes no difference for sheathing walls. Remember to leave a gap all around, and with any engineered product- don't get it wet; http://osbguide.tecotested.com/pdfs/en/el812.pdf

Gary

Thanks for the powerfully awesome links. What do you mean by leaving gaps all around? Shouldn't the osb sheating, whether inside or out be butted tight and always the ends landing on a stud? I did drill through a middle portion of the sheeting and measured my drill bit penetration. It is indeed 1/4" all around. I'm going to study your links thoroughly tonight. That will arm me with a lot of information. Like your idea about anchoring the wall to the ceiling joists and anchoring all the joists together all the way back to the wall that is attached to the house. Do I need to run wood front and back (from the garage doors to the back of the garage) or don't the trusses provide enough strength there.

Thanks for all this good information and food for thought.
 
#32 ·
I think your right, there is just such minimal sound and thermal gain off of 1" or so rigid insulation. And it would be pretty darn expensive.

How do I know the gap. Are there like spacers you can use when installing the osb, sort like those white cross shaped tile spacers? Or do I just make a piece of wood for a spacing jig?
 
#38 ·
It’s right there, last link, last paragraph, second to the last sentence.

GBR took the time to supply you the links to answer most if not all of your questions, you’d think you would be interested in the answers.

How thick is your siding?
 
#40 ·
Leave your siding alone.

OSB the interior so you can hang cabinets ect wherever you like and then

cover with 3/4 drywall for fire prevention.

Do the other steps as Ron posted , mineral wool insulation a big + for fire proofing.

Run your outlets just like in a factory in conduit along the walls.

No stranger to machining ......whatcha got ?