Drywall moves 7/8" OFF O.C. w each layer of drywall?

OK, I started writing a reply to Andy's thread and "took off" with this thought. For pics of what I'm talking about, if you haven't been there go to reference section corner detail http://www.johnlsayers.com/phpBB2/viewtopic.php?p=28924 OR andy's thread. http://www.johnlsayers.com/phpBB2/viewt ... &start=255 I recently built and "outside corner" frame and drywalled it with 5/8". I had to correct a few things when applying my drywall as I was not expecting my O.C. studs to not be O.C. with 2nd and 3rd layers of drywall. Luckily where I put 3 layers of dryall, wall was only 6' or so long so it did not matter but on a 10' wall I had to mess around, starting drywall from existing wall corner and not my new outside corner. I don't know if this has been mentioned else where, I've not seen, may as well bring it.... a "simple" thing with corner detail of multi layers of drywall I discovered which could throw someone off if not expecting or planned for it: When installing 5/8" drywall in layers to inside and outside corners, as you add more layers the far edge of drywall (which will be a seam) gets pushed off center to the stud it's meant to line up to, eventually the far edge of drywall (if not cut) will get so far off center of stud, only one of the 2 peices of drywall at seam will be able to screw straight into stud. The off center seam peice of drywall not on 2x4 needs screws to go at a hard angle, not getting good ancorage in edge of drywall OR what ????? :oops: Note an outside corner would be harder to "correct" then inside corner... inside corner drywall could be cut short. Example: Inside corner, with 3 layers of 5/8" drywall: - 2x4 frame built 24" OC, - PLUS the "on center" studs are slightly pushed from true 24" OC by 1/4" on one wall leaving room for backer rod and caulk - AND other wall "on center" studs are pushed 7/8" out from OC to leave room for thickness of other walls drywall 5/8" and 1/4" of backer rod and caulk. - Install drywall (step 1 & 2) and all seams will line up center on 1 1/2" wide stud, each peice of drywall will have 3/4" over lap on to stud (1 1/2" divide by 2 = 3/4") - Remember drywall is exactly 4' x 8', 4' x 10' or 4' by 12'. - 2nd layer of drywall... let's say 1st layer was installed horizontal, 2nd layer vertically and 3rd will be horizontal for the good finish... - Step 3 your drywall seams will not line up on stud center... it'll be 7/8" from the center of stud, got 5/8" drywall plus 1/4" for backer rod and caulk... stud is only 1 1/2" wide, 3/4" would be center but drywall seam is landing at 7/8" past this...... the next peice of drywall's edge will not meet the stud at all unless the peice which starts in corner is cut 7/8" short. is this what we are suppose to do? - Step 4,5 & 6 to 3 layers of drywall share problem - For inside corners drywall can be cut short to allow seams to land on center of studs however.... OUTSIDE corners I can't figure out for a wall longer than 12' -With outside corners, drywall would have to be lengthened to allow seams to meet at center of stud. With each layer of drywall we go 7/8" from O.C. in the direction of the corner... can't make 4' peice of drywall wider? - IF wall is less then 12 foot long... no problem 12x4 could be used. The last layer of 3 horizontally installed will meet all studs and could hold 2nd layer of drywall in place - but past that length 12' how do we get the seams to line up? that is without installing more 2x4's in wall frame to make the fasteing area of stud wider (this would be similiar for techniques in repairing drywall holes which I've learned all about :roll: ) Maybe this would not be a common problem as you could start measure of OC from an existing wall BUT, what if there is no existing wall working towards an outside corner? OK enough rambling for me, I should have just drew a pic :oops: There is probably a simple answer to this... Marc

guitardad72 wrote:

unless the peice which starts in corner is cut 7/8" short. is this what we are suppose to do?

That's my understanding and what I plan to do. --Keith :mrgreen:

Marc, seeing as your best installation is where joints never fall on top of one another - this shouldn't ever be an issue. In the best installation - your first sheets run vertically - so with a full sheet layout you would have joints at 4' - 8' - 12' etc. Then install the 2nd layer horizontally - using a full sheet - and starting that sheet on the center of the 2nd stud from the wall - cut to fit into the corner - this breaks your joints at the ends of the drywall sheets by one full stud bay. For the 3rd layer - step in another stud bay ( to 4' if framing 2' oc - 32" if framing 16" oc) and (again) cut back to fit into the corner. That's the way it's done. Sincerely, Rod

Marc is referring to the fact that the room gets a little smaller with every layer, thus requiring trimming of subsequent layers at the corners so that the opposite edges of those panels fall squarely on a stud. At least that's the point I was addressing. :-) He made many... :roll: --Keith :mrgreen:

sharward wrote:

Marc is referring to the fact that the room gets a little smaller with every layer, thus requiring trimming of subsequent layers at the corners so that the opposite edges of those panels fall squarely on a stud. At least that's the point I was addressing. :-) He made many... :roll: --Keith :mrgreen:

ummmmm Keith? That was exactly what I was refering to as well......... :wink: Rod

Argh!!!! I see that now! "starting that sheet on the center of the 2nd stud from the wall - cut to fit into the corner - this breaks your joints at the ends of the drywall sheets by one full stud bay" This is not how I wanted to celebrate my 3,000th post! :oops: Sorry about that... --Keith :mrgreen:

Rod and Sharward, Thanks for replying :D Got to admit I went on a ramble on 1st post of this thread without finishing my "self search" for answer... I presumed there had to be one. This unanswered thought has been on my mind for a month now :twisted: Correction to 1st post, outside corners would move by 5/8", not 7/8", if not following advice given by Rod 8) At my gig tonight I had some down time, did some drawing/measuring on laptop and still have some comments on the subject but... Rod,

Then install the 2nd layer horizontally - using a full sheet - and starting that sheet on the center of the 2nd stud from the wall - cut to fit into the corner - this breaks your joints at the ends of the drywall sheets by one full stud bay.

That is exactly the piece of info my mind skipped/farted on, and is how I finished one of two walls I have built (just 6 more walls, a ceiling, a floor and some destruction to go :twisted: ) Note to myself... by skipping the corner/end wall stud bay(s) in 2nd, 3rd, etc layers of drywall.. with either inside or outside corners the end piece of drywall can be cut shorter to fit.... (now if I could only perfect cutting a nice straight line in a piece of drywall :oops: ) The only thought/concern I have left (and will address even if it's only for my self) is where exactly to start measuring "On Center" from. Working with an inside corner we should start O.C. measurement from the inside corner of the two frames, not the end of sole plate of each frame. One sole plate will give the correct measurement, the other will be 3 1/2"s off because it extends past the other sole plate to make the outside corner. I remember reading code somewhere that max distance of studs is 28" and this must be the reason. Maybe not necessary but if we want to be PERFECT, we would bump the OC measurement of studs on frame that gets drywall 1st by 1/4" allowing room for backer rod and caulk at perimeter, then seams should line up exactly middle of studs. On the other frame (to corner) we would bump the OC measurement by 7/8" for 5/8" drywall already on other wall and 1/4" for backer rod and caulk. Bottom line would be to carefully plan out exactly where each drywall piece is going and plan stud accordingly so that we can follow drywall/Sheetrock/gypsum board installation instructions and drive screws no closer than 3/8" from edge into a stud . That is without driving in at an angle to hit stud or installing more studs to give a wider stud area to hit... and not miss. If studs are not planned out correctly and drywall is already up on other side frame(s) then it would sure be destructive to install an additional 2x4 next to a stud in frame for 2nd and 3rd layers. Shaward,

This is not how I wanted to celebrate my 3,000th post!

Exactly how should we celebrate your 3,000th post? Hmmm, shall we all sing.... Happy 3,000th post to you, :D Happy 3,000th post to you :shock: Happy 3,000th post dear Shaward 8) Happy 3,000th post to you.... :) And the 2nd verse: Hope you get some tonight :twisted: Hope you get some tonight :shock: :shock: Hope you get some cake and Ice Cream :lol: :lol: SPOKEN: what were you thinking... :roll: Hope you get some tooooooooniiiiiiiight... :P :P Then followed by a slightly re-vamped version of "you says it's your birthday" by the Beatles. My insperation for revamping/rewording the song usually comes as I sing it, seeing reaction of b-day person and crowd... can't do this typing as half the fun comes from the verbal diaria coming out as I think (sing) with my mouth open. :roll: OK I'm done. Marc

I love the song! :D I think you DO want to drive your edge screws at a slight angle to ensure good penetration. My framing book shows sheathing nails along edges are to be at an angle. I did quite a bit of angled screw driving on my outer ceiling... :roll: --Keith :mrgreen:

guitardad72 wrote:

Note to myself... by skipping the corner/end wall stud bay(s) in 2nd, 3rd, etc layers of drywall.. with either inside or outside corners the end piece of drywall can be cut shorter to fit.... (now if I could only perfect cutting a nice straight line in a piece of drywall :oops: )

Do you own a drywall square? They make it pretty easy.......

The only thought/concern I have left (and will address even if it's only for my self) is where exactly to start measuring "On Center" from.

What a convoluted path you traveled there - it isn't that difficult or deep - go take a look http://groups.msn.com/RecordingGroups/s ... snw?Page=3 Look at the corner detail Rod

Rod, That tif Pic in last post is not showing up, for me at least.

Do you own a drywall square? They make it pretty easy.......

YUP, bought one from HD for $10-$15 as I came near the end of applying drywall to walls I've already built. Guess I should say from amateur DIYer point of view: Scoring drywall with knife with straight piece of lumber or drywall T square is easy. Just got to make sure the pressure of knife is going the right way to score and not slip causing a score line which could effect the bending/breaking of drywall at a point where you want it to break. I've done this. Bending/breaking the drywall then cutting the paper on back to completely separate the two pieces is easy ONCE YOU"VE DONE IT A FEW TIMES. BUT my current success rate of having that drywall piece fit with 1/4" clearance of spot I've cut it for is 50/50. The cut edge of drywall is straight BUT that straight line always seems to be jaggedly straight. Sometimes (well 50/50) there will be bits of gypsum sticking out far enough that drywall won't fit.... then I either shave edge down with utility knife OR attempt another cut of 1/4" which IS NOT EASY. Another factor would be presuming that the area I am cutting drywall for is square, and I've learned NOT to presume this the hard way. Even though I built (my part) the frame square, it does not mean existing portions of structure are square. I know gaps can be taken care of via backer rod, caulk and mud... (this is why I bought 2 thickness's of backer rod) BUT would it will sure be nice when I get to the point where I can cut every piece and have it fit just like I want without having to make the dreadful 2nd cut of 1/4" OR use more Mud or caulk then I have to. I do measure twice, have read almost all instructions and... it's not that same as cutting a piece of wood with a saw getting a really straight edge. Years ago the 1st piece of drywall I ever cut, I FOOLISHLY used a circular saw. What a mess that made, dust every where. :oops: I'm done complaining & babbling about drywall...

Quote: The only thought/concern I have left (and will address even if it's only for my self) is where exactly to start measuring "On Center" from. What a convoluted path you traveled there - it isn't that difficult or deep - go take a look

Currently I can't see the corner detail picture, I should rephrase.... I know where to start measuring from: inside edge of corner, then minus 3/4" on 1st stud. I was referring to BUMPING the start point of 1st Stud as I stated to in later part of that post for thickness of caulk (1/4") for 1st drywalled wall of corner and then caulk & drywall (7/8") for 2nd drywalled wall of corner. AND be careful to remember that one of the soles plates extends 3 1/2"'s from the inside corner mark... same thing's apply to outside corners... I don' think this path is to convoluted :twisted: ,I've just not seen/remembered this in any DIY instructions I've found for measuring OC and feel like it might be an easy mistake to be made by amateur DIYer like me.... I almost made the mistake, till I thought through the edge of every peice to it's center point on stud. However if the "mistake" is made you can always cut the piece (drywall, sheathing or other) on 1st layer short to make the outer edge center on the 1st or 2nd stud in wall, as you described previously about 2nd and 3rd layer drywall. Marc

Having done a lot of drywall cutting so far on my project (outer leaf, beef-up), all I can say is that I echo all of your cutting experience sentiments! :roll: --Keith :mrgreen:

i can't see the picture either

BUT my current success rate of having that drywall piece fit with 1/4" clearance of spot I've cut it for is 50/50. The cut edge of drywall is straight BUT that straight line always seems to be jaggedly straight

Get a gypsum board file. Cut then use the file makes nice clean edge and a mess on the floor :wink:

Years ago the 1st piece of drywall I ever cut, I FOOLISHLY used a circular saw. What a mess that made, dust every where.

Ouch ! :lol:

Another factor would be presuming that the area I am cutting drywall for is square, and I've learned NOT to presume this the hard way. Even though I built (my part) the frame square, it does not mean existing portions of structure are square.

I know how you feel, when we revamped my mothers house absolutely nothing was to sqaure. That was a freaking puzzle. took two time the time to do. But you did make all new construction to square did you ?

click on the link above now - I have no idea why it won't show the pic - BUT..... if ya can't bring the mountain to Mohammed - bring Mohammed to the mountain. At last that's what I heard........ Sincerely, Rod

Rod, thanks for diagram and fixing the pic. I'll attach for others, to this post. Numbers are hard to make out... Inside corner pic, distance from both studs to corner is 2' 2 3/4" and the outside corner pic number is 1' 11 3/4" Note, Mohammed (or the mountain :roll: ) is still convoluted and will draw pic and post in a few days... which may solve convoluted state of mind. 8) orangenumerik,

Get a gypsum board file.

Spent (what felt like) 30 mins searching for that tool on online drywall tool stores. Are you sure you got the english name right or are you refering to a regular file? This does sound like a cool tool to hang on my new peg board :twisted: Marc

guitardad72 wrote:

orangenumerik,

Get a gypsum board file.

Spent (what felt like) 30 mins searching for that tool on online drywall tool stores. Are you sure you got the english name right or are you refering to a regular file? This does sound like a cool tool to hang on my new peg board :twisted:

You couldn't find it because it isn't really a file - it's a rasp....... Here: http://www.all-wall.com/acatalog/Drywall_Rasps.php Go about 1/3 down thepage and look for: Stanley Surform® Rasp Great tools those are.......... Sincerely, Rod

When doing my studio walls, I used something that looked like a small plane (maybe 3 or 4 inches long) that had a "raspy" blade on the bottom and a big cavity just above it to catch the gypsum, and a hole in the back to drain it every now and then. I can get a picture if you need one. Try "drywall rasp" in your search. Found this: Stanley Surform® Rasp ITEM # GB21399 at http://www.all-wall.com/acatalog/Drywal ... HgodZSR2uA Hope that helps a little. What I ended up doing was getting a long metal straight-edge designed for cutting plywood and paneling and such, then using a Dremel tool with a drywall bit and held it along the straight-edge and just went down the length of the sheet. This was made easier because I had a big stack of drywall to work from so we'd just slide the top sheet over enough to attach the straight-edge. len

Sorry about the wrong naming Marc. Everyone around here call that a GB file. Thanks to Rod, one more word in my book.

Cool! 8) I'll need to get me one of those when it's time for me to do my inner leaf drywalling.

Drywall square, utility(razor) knife, box of blades, surform/GB knife/rasp, Rotozip, dust masks, someone ELSE to do the work :lol: ... Steve

knightfly wrote:

. . . knife, box of blades . . .

I'm a big fan of this... Stanley 18mm DynaGrip® Snap-Off Cartridge Knife

• Blade cartridge automatically slides new blade into position after old blade is removed
• Stainless steel blade dispenser cartridge resists rust
• Ergonomically designed for comfort and cutting power
• Smooth, slider mechanism features audible click stop and is self-locking
• Strong, durable tri-material construction with soft-grip panels
• Hang hole for storage or lanyard
• Blade capacity of six heavy duty or five extra heavy duty blades
• Comes with six 11-301 Heavy Duty blades (equals 32 points)

I have this thing and I love it. They sell 'em in the Tool Corral at Home Depot. It's quirky sometimes, but overall it's great. 8) --Keith :mrgreen:

I prefer the OLD style Stanley, where you have to take it apart with a screwdriver - so far, none of the sliding types I've tried can hold up to serious use without the blade pulling out further than you wanted it. Maybe if you held it at a steeper angle to the direction you're pulling to make the cut... Steve

I started my beef-up drywalling with one like you describe, but I was going through blades way too often. Steve, you gotta try one of these things. :) The ratchet is stainless steel. This ain't that 99 cent bin plastic job! ;-) --Keith :mrgreen:

Well, alright; after all, it HAS been at least 15 minutes since I've bought a tool :oops: ... Damn, Homeless DeSpot is CLOSED... :cry:

Let's open a brick-and-mortar 24-hour tool store. ;-)

"Let's open a brick-and-mortar 24-hour tool store." Yup, good idea; I had just over 17 seconds of free time yesterday that wasn't filled, felt so WORTHLESS... :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: :mrgreen: