using sheetrock for exterior sheeting?
i’ve never seen this,but a friend of mine is having a 300k, 2800 sf house built 10′ and 12′ walls. 4’osb bracing on each corner,then they are using a 2’x8′ sheetrock for sheeting,yes sheetrock says right on the edge!one wall is 82′ long with corner bracing on corners and thats it.plus they are putting it up with a roofing nailer that rips thru the paper and goes about3/16 into the gypsum. it looks like if we got a gully washer tonight it would fall off the house.the siding for better or worse will be drvit stucco. i’m thinking if the neighbor kid hits a hard fastball it could go thru the 1/2″styrofoam,1/2″ sheetrock and another layer of 1/2″sheetrock and hit you watching tv lol. tell me what you think. oh side note not 1 pc of treated wood on sill plate,when framers got done they had some treated left they didn’t know what to do with,so they framed a garage door opening with it! you never know when rot will sit in 12′ off the ground!i’d like to know hat you guys think and if this is something common and i’m just a dumba__.thanks larry
hand me the chainsaw, i need to trim the casing just a hair.
Replies
In my framing daze we were asked to sheet a house with exterior gypsum (brown board). I had used this previously over plywood or osb for fire protection but this was the first time as the only sheeting.
The house was a two story with full basement and we were working on the main floor. We had a coil nailer but were waiting for nails. Sheeted the walls with the gypsum, tacked it on with 8's and was told to raise the walls by the boss. He figured we would nail it off after the nails were delivered.
The next morning we were greeted to a house with crumpled gypsum board on all four sides. Our 8's which worked fine to tack up the plywood failed miserably. Boss needed to replace about 20 sheets.
Is the sheetrock being used rated for exterior use?
We also did some houses with Thermo-Ply. Essentially a heavy duty cardboard sized at 49 1/2" to overlap at seams. Had dots every 3" for nailing. Building inspector would use his credit card from the inside to see if the walls were nailed properly. To top it off the siders installed original LP siding over the top. Talk about wavy walls.
Pardon my trip down memory lane.
Owen Roberts Group
10634 East Riverside Drive # 100
Bothell, WA 98011
http://www.owenrobertsgroup.com
I have gyp sheathing on my 1960 ranch house here in Pa. Back when Levitt was going to town around here throwing up houses for the boomers to be born in, they came up with all kinds of materials to get the houses up cheaper and faster. Some of them were good, some not so.
The stuff is not particularly structural, but is fire proof and rot proof. I've added onto the house a few years back with regular 1/2" cd and resided the whole thing. I think this type of building has been around for quite a while.
The problems with synthetic stucco trapping moisture behind it have been fixed by putting water flow channels on the backside.
Seems like a pretty dumb idea to me to use drywall where it is likely there will be water at one time or another.
WOW!!! - I'm in shock... Just when I thought I'd heard of everything... I'm giving you homework :-) Please find out exactly what kind of sheetrock it is. I wonder if they are going to put any kind of building paper on it...
also, >> one wall is 82' long with corner bracing on corners and thats it. << That would pass inspection in my neck of the woods... Obviously the sheetrock (or whatever it is) isn't structural, hence the OSB on the corners, but we are required a 4' wide structural panel (or diagonal bracing) every 25' (I think it is).
this stuff says "sheetrock"brand right on it. paper is a dark grey ,other than that looks just like 1/2 rock larryhand me the chainsaw, i need to trim the casing just a hair.
well i guess the concensus is that this is not unusal,but nobody wants it on there house! so i guess i'll keep my mouth shut to my buddy. it's his house and if he's making the payments oh well.sure glad i'm not. thanks everybody for the replyshand me the chainsaw, i need to trim the casing just a hair.
http://www.usg.com/navigate.do?resource=/USG_Marketing_Content/usg.com/web_files/products/prod_details/SHEETROCK_Brand_Gypsum_Sheathing.htm
Matt
Occupants of the house should be a little worried about the "scores and snaps easily" part of the description in the marketing blurb on that web site. Some of the posts about gyp-board used for fire protection and closely-spaced houses make sense. I just can't see any advantage for the stuff in general construction, other than it's cheaper than OSB.Good, fast, cheap, pick any two.
I saw thqat dark grey exterior sheetrock on a church building being built several years ago. The day I was on site---worked for the utility company---it had been raining lightly, off and on, for three days. The crews were installing during the light and no rain periods. I looked pretty closely at sheets that were getting direct rain---saw no problems at all. Stuff was installed on steel framing with self tapping screws---just like wood framing.I decided to stop taking life so seriously, it is, after all, only temporary.
http://www.gp.com/build/product.aspx?pname=DensGlass+Gold%c2%ae+Exterior+Sheathing&pid=3515&hierarchy=pc
http://www.us.bpb-na.com/gypsum/table.html
http://www.nationalgypsum.com/products/?query=cat:1&product=6
http://www.cmhc-schl.gc.ca/publications/en/rh-pr/tech/98114.htm
http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/C1396C1396M.htm?E+mystore
I remember many years ago watching commercial building go up, and they used a lot of 2x8 sheetrock for sheathing. All the joints got taped. I never got close enough to see how it was done, but I suspect it was screwed because the used metal studs. Most of the time it was 1, 2, or 3 story office buildings.
I'm sorry, I thought you wanted it done the right way.
Gypsum sheathing is required on any building here in Chicago. When we're building in the city, we use roofing guns to secure the gyp, but make sure the depth of drive is set properly. Never had a problem in the 15 years or so we've been doing it.
In some places... building on the line or within the setback (with a variance)... they require 'gyp-lap' gypsum sheathing on the exterior of the plywood/osb sheathing, and under the felt. IIRC the gyp-lap I've used is 2x8 and almost an inch thick, with shiplap edges, no taping required. Also been required to put a layer of 5/8" on the outside of a building that was on the property line when we remodeled it. No openings allowed in that wall. Felt over rock in that case too.
Either way, it's to slow the spread of fire (i.e. a fire inside your building getting out and spreading to the neighbor's).
The framing carpenter I worked with a while back and I put new MDO on a house that had exterior grade drywall on the soffits and fascias. These were special features where the fascias were about two feet wide and the soffits about three feet deep. The drywall was the exterior skin, nothing over it, and it had all the strength and integrity of wet oatmeal (and looked about the same too). It was easy to take the drywall down though!
Sounds like they are installing an EIFS System. This has been used in commerical constraction for years.
It's the pour mans stucco.
busta :0)
From a web page discussing alternatives to plywood and structural OSB for sheathing:
"The recent dramatic upswing in structural panel prices and tightened material supply has created concern among the residential construction industry. Several reasons for the price and supply volatility include:
Plywood and OSB are considered commodity products and are used interchangeably. Supply or price characteristics that apply to one typically influences these characteristics in the other sheathing product.
Uncertainty in price or supply of OSB and plywood has prompted the industry to consider alterative sheathing approaches for residential housing.
Gypsum
Gypsum products come in a variety of material configurations including exterior-fated gypsum core with paper faces, gypsum core with glass mat faces, and a core of gypsum, cellulose, and perlite with water-resistive faces. Gypsum panels are used under brick veneer, and stucco finishes. An advantage of gypsum is the ability to obtain a fire-rated wall assembly. Gypsum panels, however, must be handled carefully and the paper-faced products need to be sheltered from precipitation.
The primary manufacturers of gypsum panels include USG, Georgia-Pacific Corporation, and National Gypsum Company. Representative brands include Fiberock, Densglass Gold, and Gold Bond respectively."
Gene Davis, Davis Housewrights, Inc., Lake Placid, NY
Edited 7/24/2005 1:48 pm ET by Ima Wannabe
This reminds me of the houses that were thrown together in Houston during the oil boom of the late '70s. IMO, using gypsum board on an exterior wall falls in the "desperate people do desperate things" school of construction. What's next, 30# felt directly over the studs with siding on top of that?
aob,
Here in NYC exterior gypsum is required on any side of the sturcture that is less then 15 feet from the property line. On my house I first put a layer of 1/2 cdx and then a layer of 5/8 exterior gypsum on the sides. The front and back I use 3/4 cdx.
The current issue of Walls & Ceilings Magazine has an article on this subject. The article is not on their website yet but should be anyday..just google Walls & Ceilings Magazine and search the articles. The crux is that exterior gypsum sheating retards fire.
We use the Dens-Glass Gold on the buildings in areas that will get Ephus (not sure of the spelling), synthetic stucco similar to Drivit. It is spec'ed by the Ephus contractor because of the way it bonds to their Styrofoam sub-surface. That is probably the reason you saw it in residential const. As a shear panel it has very little integrity. I would hope the walls were built with a rack brace of some sort. It is exterior grade and will hold up to weather. our baseball comment made me laugh and is very true. I can see it becoming a challenge for the kids.
Edit: After rereading your post I think that you are witnessing a problem that we are going to face more and more as new material technologies enter the building industry. These products are really installation dependent if they are to perform properly, and sadly we are going to have people, crews, builders and developments that won't be able to fit the bill and and will turn some potentially good engineering into a mess. Not that I think it is necessary brilliant engineering, but it may become necessary engineering
Edited 7/28/2005 6:48 pm ET by quicksilver
Hey Quicksilver, it's EIFS..."exterior insulation finish systems" ain't jargon grand?
Hows D.C. doin......
Thanks. Like a lot of us I appreciate learning such things.
And many Contractor's Liability Insurance carriers won't insure you if you're using EIFS.