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WALL DIMENSIONING

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yoiyoi

Could someone clear this up for me- what is the conventional way of dimensioning new interior stud walls for cds. Most sources i have come across say stud walls are dimensioned to their centers whereas cmu is dimensioned to its face and then its thickness and so on ...
i've come across a couple of people who think other wise- they suggest the dimension should be to the face of the stud (ie the clear distance of b/n the walls)

could someone explain the rationale for these differing conventions if any

Blind Pew

I think the current trend is to dimension the stud thickness. Maybe it's regional or something, but that's how everyone I know does it. Either way, it's going to be correct. I think the rationale is that the framers want to eliminate a step.

Mum

No! No! Not this! We've gone around this same issue in my office before and it made us crazy. We used to have a principal who insisted on drawing a 3-5/8" stud wall at 3-5/8" in cad with 5/8" gyp both sides in cad. It was ridiculous. He retired. We had a party.

In my own opinion, centers are hard to do because you frequently need to keep clear space or a hold dimension and it's hard to look at a plan and mentally do the math. We are starting to do 5" stud walls and 8", 12", etc. masonry because we've had people who don't take into account clear spaces with a 4" stud wall. We did stud walls at 4" for a while, but we found the person doing the plan had to take into account the finishes, and some didn't.

I'm also curious what others do.

calatrava

we usually do the actual thickness of the exterior walls. for example, i'm finishing up a department store and the total thickness of the bottom part of the wall is 10 1/4", so we draw 10 1/4" in plan. interior walls are different, we round off to 5" which consist of 3 5/8" studs plus 2 - 5/8" dry wall. i'm also curious what others do aswell.

kn825

Just dimension the critical clear spaces. Allow breathing room for the builders to screw up. Locate the important walls off of a column grid or foundation edge.

R.A. Rudolph

I've worked in places where we did it both ways... my contractor partner tells me he doesn't care which way it's done, but then he went to school for architecture and can add and subtract so he can pretty much figure out where things should be regardless. For most of the larger jobs I've worked on, we dimensioned to the center of the framing, whether it be CMU, wood studs, steel, etc., except on the ends of the bldg. we would dimension to the face (framing or finish, there has to be a tolerance anyway so it doesn't really matter). I think this has become more of an issue with the computer, because you really can't make it ambiguous, you have to be exact. At the last office I worked in my project manager was an older woman (in her 70s!) who couldn't get why it was an issue. But that was because she didn't realize that you really can be exact to the 1/16"... anyways, I found that dimensioning to the centerlines of framing is helpful esp. if you are working with a regular structural system (which most projects are). For ADA compliance we would then dimension to the face of finish on the enlarged plans as required, which worked out well. Definitely don't get into worrying abou the thickness of drywall, it'll never be built that exactly anyways...

geezer

aarrghh....this argument was started in the original Symposium... There indeed may be regional preferences, but from the design build side of things it goes like this... make drawings friendly to the builder...make them usable... Don't assume he can "figure it out" --the less things he has to "figure out" the much happier you will be. And he will be happy to. He won't spend as much time trying to stick you with an E&O change order if he is too busy working from your tidy set of clear documents.

If you are a framer trying to lay down a track, how in the name of buff construction dude are you supposed to layout by the centerline dimension? THE TRACK IS SOLID! HELLO??! Bubba is not gonna add two layers of 5/8" gyp and the mortar bed and oh yeah the 1/2" greenboard and the tile thickness and divide by half to subtract from your dimension so he gets to the right place that makes your clear dimension work....

freinds, just do all your dimensions to the face of stud and if a critical clear dimension is required, put it on the plan. You should be able to calculate the thickness in your head and christ's sake keep your layout dimensions to even inches. If your floor plan is so tight you need to look for extra layers of skimcoat to make a clear dimension something is wrong...

And why use 3-5/8" studs for new construction?? Use 4" and you get more strength and easier dimensioning. If you need to match existing wood 2x or 3-5/8" steel, use it only for the wall you need to align.

And give your self some wiggle room. Autocad makes it easy to forget about construction tolerances. We ain't building swiss watches ya know...

Never close a dimension string. Leave an open in an area that isn't critical.

How do you layout a wall from the centerline of an already poured or layed concrete wall?? Joe Framer has to figure out if it is a 4" or 8" block or even a 12" block...and subtract half the dimension from your dimension oh my god my head spins...Dimension from the face of all CMU or CIP walls. And your structural engineer will love you. Remember, the structure is there first, so don't dimension from the outside face of a wall.

That felt good.

whistler

I' m with him. Face of stud / cmu / cip / sip panel all day long! The only time we do the centre of anything is for log work, timber posts and steel posts and that's only because the actual size can vary and that't how a timber wright would lay it out.

TED

R.A. Rudolph

mmm, good points geezer. I feel like our engineers always dimensioned from the center, even of concrete, but maybe i'm remembering wrong... btw, my partner(husband) is a general contractor, and really doesn't care how things are dimensioned as long as it's clear...as you said, it ain't gonna be exact anyway.

engineers usually don't dimension their plans. am i missing a good eng.?

satan

if you're working with carpenters and masons who can't add and subtract i really can't imagine what kind of work you do.

for exterior walls, there is an outside dimension you have to note... and where that is will depend on the type of construction. for interior partitions it really makes no difference, and if you care about something like a clear dimension, than make it obvious that its important.

seriously, if you're talking about wood frame or lgmf and you want to set dimensions of interior partitions, go to the centerline FOR YOUR OWN selfish self. isn't that easier for us? fewer dimension, whole numbers, faster to change, no ambiguity, and walls types can be developed and revised independently. i think the choice is clear.

this response is terrible on so many levels. we are not making the drawings for us.

pia555

For 20 years I've designed residential bldgs. A note on the plan explains "Exterior walls are measure from face of exterior sheathing to interior face of drywall and interior walls are dimensioned face of drywall to face of drywall". Over the years I've heard complaints from builders but never had a serious problem. Sure a building is never going to end up the precise dimensions you layout. There has to be some forgiveness built in. Otherwise, we would need Nasa build our buildings calculating for expantion and contraction. To dimension a whole building using center of walls give me the creeps. That would require the builder to do more math which would lead to more screwups. Critical dimensions are labeled as critical. Dimensions that aren't critical can get a +/- meaning there is some forgiveness. An unfinished dimension string isn't a bad idea. I just always completed mine to verfiy the overall dimensions. But even then there are partial strings for certian areas Even when the dimensions were laid out in such a way a blind person could build it. Some subcontractor would still find a way to screw a part up. Like the surveyor who laid out one of my buildings on the site using the first floor plan instead of the foundation plan. The whole build grew by 5 inches which set in motion a few uneasy moments.

Brim

In our office we dimension to the face of studs & masonry (usually exterior side of masonry / slab edge). For 2x4 studs we draw walls at 4-1/2"....3-1/2" acutal plus 1/2" GWB ea. side. Let the framer figure it out from there - they're not complete idiots.

geezer

Wow just reread my post and I really need to get back on my meds... the spelling errors! Zut alors!

Satan: I am dealing with lowest qualified bidder public works contracts. Assuming that the subs will even be able to read the specs is a gamble, so more subtle math equations (pace Brim) will really twist thier shorts.

I don't think our clients would like to hear comments like "for your (the architect's) own selfish self." If a contractor complains to the owner about the architect's dimensioning, which is a aspect of drafting that anyone can appreciate and fully understand, he will question your decision about other aspects of the work as well...

As for being selfish, a clearly and easily dimensioned plan will save you hours and hours of time and profit in the field trying to get the framer to do what you wanted in the first place...So I guess I am being selfish, but in my own enlightened best interest and ...ultimately...for my client and the project.

Additionally, measuring from face of stud to face of stud neccesitates the draftsperson to investigate the wall type. They'll get to know the different make ups of 1-hour construction, non-rated, etc and the components of a wall assembly, gypboard (which thickness? which type?) finishes (mortar base? thinset?) utilities in the wall (4" sewer line in a 4" stud wall?? Good luck!)

Sorry about the rant, but this is the stuff that unwittingly takes 80% of your time in a normal production office...

PostDepot

would you fuckin' STOP referring the builders, framers, contractors etc.,
idiots or stupid or any other degrading names. only the rookies call them names..

having dealt with contractors, have seen and heard about the shit they pull - most contractors are a-holes.....build it the way it was drawn and bid, a-holes. the worst however are EPDM contractors, they take the cake.

geezer

I second OA:
AND low bid jobs are really a different animal and you need to CYA. You should hear what folks in the field call architects when they review a plan that can't be laid out in a logical manner. And trust me, it's not only rookie contractors, framers, etc that call architects names.

MAKE THE BUILDER YOUR FRIEND and you will be happy. Partner with the contractor, Don't antagonize. Save your strength for the real battles. Shit, dimensioning is the tip of the iceberg.

Protect the integrity of the design.

in the office i work at we dimention to the stud wall , rough framing. and if you use architectural desktop you draw acctuawalls so you just type in 5.5 " and just lay em down .02cents

but im sure every knows that ;)

silverlake

I worked as a carpenter for some time so I have an idea of what is most effective on the other end: always dimension the face of the block or stud, not the finish. when the framers are out in the field they shouldn't have to subtract finish thickness every time they are pulling a dimension; your setting them up for mistakes otherwise. if you have 3-5/8" studs, you just have to dimesion one side the wall (not the thickness of it) to locate it in space and you don't end up with fractions. if you have fractions of an inch on the floor plans the builders will think you are a jackass.

whistler

Dimension to the face of stud, dimension to the outside face of sheathing for outside walls and then have wall types indicate the thickness of stud. Draw it to scale ( ie 3 1/2", 5 1/2" etc) but if you have to change wall build up becvause of extra drywall or different drywall finish ie 1/2" or 5/8" type x you don't have top redraw just change the wall types.

I find it helps keep it simple when you move from a schematic level through the CD phase if you draw the wall correctly to begin before any of the finishes need to resolved you can save some time and makes changes later down the raod pretty straigh up.

If you need to dimesion the thickness of a wall for a contractor because he says he need it, I would stay clear, he shouldn't be hired to build your project.

norm

draw the wall at it's correct thickness, so that you have an accurate drawing.
dimension to the face of studs if it's new construction - because that's what the layout guy needs to know.
i just don't get what's so tough.

le bossman

i think it depends on where you are and who your working with. i've seen it done three ways:

dimension the total wall thickness (including furring, gyp boards, etc.)

dimension to stud/block thicknesses (the most common way i've seen, especially useful if you have a wall schedule set up which shows the other information

dimension to one common side of the wall, i.e. you would dimension distances between walls at the stud, with you dim set to the lower and right faces of all the studs.

including all the thicknesses isn't really necessary, or even desirable on a project with enough wall types. a wall schedule with the walls all labeled with tags is much more clear and easy to read, and it makes more sense to put all the info in a note than to expect a contractor to be able to tell what is 3/4" OSB and what is 1/2" sheetrock in plan at 1/8" scale

don't draw walls at their correct thickness, you'll end up 3/8", 5/8", 1/2" dimensions everywhere. don't forget that most of your drawing sets will have wall partition schedules, plan details and wall sections that at those particular scales, you will want to represent cmu and other materials to their correct sizes.

i just did a project that had a mixture of load bearing masonry and steel structure. i dim'd the center of the masonry partitions in the bearing wall, and did an =/= dim, that in conjunction with partitions called out will tell the mason all he needs to know. dimension when you can from steel centerlines - seeing as that steel will be in prior to the mason getting there...

David Cuthbert

Measure new stud wall to the centres it has to do with timberconstruction standards. Simple measure line indicated run a parallel chalk line to the floor, nail in double footer - ala Bob Vila (bob the builder?) It goes back to when structural timbers, especially 2x4s tended not to have a true edge. Nowadays 2x4s come straighter than anyone on the QE4. But I accept that yes it is regional. Also its near impossible to get a 4" stud wall closer to 5" (4 7/8" with most blue-bond gyp board)

ah yes but with CMU blockwork measure to the centre as well if the finish is to be fair-faced.

norm

this amuses me.
betadinesutures - refer to the post by silverlake above.
if you think about what the guy building the thing needs it solves the question for you.
simple.

melvin

What silverlake says is what I've always been taught, and now that my current firm only dim's to face of finish and clearances, I really believe it.

Dimension to face of stud, and keep the finishes to yourself. that way if they build it wrong, they have no argument. Liability aside, the chances that the architect who has been working on it, detailing, etc will get it wrong on the CD set is far less than the chance that the apprentice construction worker will screw it up.

In my previous firm we were drawing all walls accurately from DD on. Every line, the stud, the gwb(whatever finish) and cavities were all drawn, and the face of stud was the bold line, not the face of finish, just to reinforce this on enlarged plans. It was simple in autocad, and actually did not take that much longer. I loved it cause it because you could easily open up a plan and see what had been thought out carefully, and what still needed development. It also enabled anbody to jump on the project and know what the walls/details were made of.

norm

melvin gets it - some of the rest of you must have gone to the gsd - hehehe.

jhopkins

i will only add that i hade to pick up a project in CA that the previous person had dimensioned the interior partitions to the finish face and set the dimension tolerances to 1/2" with degree tolerances set to the nearest degree. she also didn't believe in OSNAP and had a penchant for overiding the dimension text to read what she WANTED it to read and not what it actually was. now i have interior partition dimensions such as 9'-3 3/8", degrees such as 38.365, and a contractor that yearns for the day when we will both be alone in a room with no witnesses.

Devil Dog

dimensions standards in my opinion are very regional.

i personally feel that steel structure should be dimensioned to the centerline. masonry to the face. wood studs/ metal studs to the face and timber to the center (because it's probably structural).

if a building is wood or metal stud, even exterior walls, dimension from the face. it's pretty dam easy and i think the framers will appreciate it.

steel structure should be dimensioned from the centerline. any walls from that will be detailed from a plan detail showing wall justification. dimension from face beyond that.

i always draw materials to their true dimension, then dimension from the face of that 3-1/2" stud or 4" stud. i never show finishes because 99 times out a hundred, 5/8" isn't going to matter. the time it does matter, i make sure things are where they need to be. if 5/8" is gonna kill you in a certain area, make dam sure it's not gonna kill you. why spend effort hunting down fractions of an inch where it doesn't matter. spend effort where it counts.

the easier you make plans to read, layout, clearly dimensioned, logical. . . the more helpful the builder will be. dimensioning is a dumb fight to pick. pick the good fight about design, not dimensioning.

just my opinion.

whistler

Devil Dog ....its a good opinion. I always though what would I want to see if I had to build it? Generally "keep it simple stupid".

Blind Pew

I don't see what the big deal is with limiting dims to whole inches. If you have a couple 1/2 inchers or even a few 1/4 inchers no big deal. Of course try to keep whole units, but sometimes you just can't. Carpenters have tape measures that actually divide inches into 16 equal increments you know.

The problem becomes a critical one when you have a row of 60-100 "standard sized" offices that all must use the same furniture system. You can end up with major problems and a costly redesign or change order.

and don't forget when dealing with masonry coursing is major issue, even horizontal coursing....

lexi

inside face to next inside face. do not dimension in plan. use partition type symbol on each partition.

Brim

I agree with that lexi.

JG

"Could someone clear this up for me- what is the conventional way of dimensioning new interior stud walls for cds."

somehow I don't think things are any clearer for yoiyoi but it's an interesting discussion nevertheless.

Ormolu

There are ANSI standards for dimensioning different types of walls (in the same way that there are ANSI standards for how dimensions should appear on drawings - though there are several acceptable ANSI options for that.)
The standard for an exterior frame wall is to dimension from face of stud to face of stud. For interior frame walls they "prefer" the method of dimensioning from face of stud as well, though to dimension from centerline to centerline is also an "acceptable alternative." Dimensioning a stud as "4" rather than its actual dimension is their "preferred" method, though they acknowledge that actual dimensions could be critical, so the method of including fractions of inches is an "acceptable" method.

There are similar written standards for all sorts of masonry walls, cavity walls, composite walls, etc.
Clearly not all architects/firms follow these standards - but if you're looking for some kind of written "rule book" for these things, that's it.

aldorossi

Right on, Geezer, et-al. The less you leave for the contractor to "figure out", the happier everyone will be. Back in my hand drafting pre-cad days, we even drew the dimension lines slightly inside the wall line so that it looked like the dimensions went to face of stud and not the surface of the wall. Anal? Yes. Bt I always thought it was a precise way of doing it. (Of course there was alays a general note/legend saying where dimensions were taken from).

As a matter of fact, I would love to be able to do the offset dimension thing in CAD as well. If not for precisions sake than for clarity and consistancy. It would also generate the dimensions precisely to the face of the studs.

I know I have opened myself up to howls of derision from the younger crowd, but, this has been an issue during construction.

Ormolu

aldo: my office does this in CAD sometimes - but but we're using ArchiCAD and VectorWorks, so it is easy because walls are really composite objects that understand the components inside them. (I haven't used AutoCAD in awhile and don't know whether this is easy these days or not.) We have our wall types set up with "cavity lines" at the appropriate thicknesses of the finishes - so we can snap to them when we dimension - but we have those lines set up to be the lightest, thinnest line type, so they either don't print, or they print extremely lightly. It isn't any more difficult to draw a wall of this type than to draw a single line.

A

I have always seen steel stud walls dimensioned to centerlines. That was in offices in Minneapolis, Chicago and Philadelphia. Where is the region where you dimesion to face of a stud wall for interior partitioning? I've never heard of that before.

let me ask, and this is just me asking, how does a framer lay down track for metal studs if he can't see through the track? the way i do it, is to dimension to one side of the wall - assuming a string of dimensions - thus allowing for the guy to lay down a track along a line he can see, that and having partition schedules is immensely important...

Some of the track has slots for the anchoring drilled/punched in the center and if you have a chalk line (in the right place) you just slide it around until you have the line in the slots.

Mum

Isn't that the reason they make the little cut-out holes in steel studs? So you can see through them to the chalk line on the floor?

;)

the holes are for conduit, i thought. if the holes were for chalk lines, how would you know you were centered on the hole? seems like an awful lot work to check the squareness a wall. it seems easier to lay down a line and lay the edge of stud along a straight line, less of a concern for a wavy wall....

Mum

Aahhh! And I bet you're going to tell me that those hollow cells in CMU are for grout and rebar? C'mon. Everyone knows those are also so you can see the chalkline on the floor!

aldorossi

Ormolu:

Brilliant! I Feel like a schmuck for not thinking of the multi-line thing, which you can do in AutoCAD.

Cheers, mate!

well Mum, i just checked my Marino Ware guide and they indicate that metal studs - vertical members - have punch-outs 24" o.c. and tracks - horizontal top & bottom members - do not have punch-outs, in fact there is no option indicated to get that, but there is the option of having metal studs without punch-outs. perhaps there are stud tracks with punch-outs? again my question to you, how do manage to make sure your track is centered? rebar and grout whats that?

Mum

I knew you were going to nail me on that one! I was at a job site today to discuss a framing issue and I found steel tracks (holeless, of course) staring me in the face as an omen of my mistake.

I'll go with x-ray vision now. Except for the CMU. I still say the holes are so you can see your chalkline! :)

A

The holes are for the conduit and it requires less material so why not. I haven't seen tracks with holes but to run conduit I've seen tracks drilled through. If dimensioning to centerline you can snap a chalk line and line up each end of track with the centerline, unless doing a radius.

satan

on longer spans the 'holes' in a stud are used to place lateral support channels.

el jeffe

the advantge of track layout on a centerline is that you won't ever place the track on the wrong side of the chalk line, right? i've seen framers use a rotating laser to provide a virtual chalk line - that comes pretty close to x-ray...

josephamodeo

i think the convention is that its UNDERSTOOD that architects are DOGSHIT... everyone knows this... basically all architects are required to hold to is exterior footprint because this is usually suspect to building codes... whereas if an interior room measures 10FT on the plans but after being built is shifted a half inch or two due to ALL OF THE INTERIOR WALL THICKNESSES BEING COMPLETELY INACCURATE ON THE PLANS... this will typically pass inspection because the architect did not callout exactly what type of lumber to use etc.. so therefore no one can claim the builder didnt follow the specs etc because all the architect did was draw in a generic 5" wall... which in reality is 4.5" with studs/sheetrock on both sides... but if the builder doesnt hold to the exterior dimensions on the plans now youre dealing with a host of zoning regulations about the plot to footprint ratio etc etc and the house will not pass inspection...

LMAO... and now we have architects above talking about how their offices started just measuring from the exterior dimension to the center line of walls because they know just how fucking lazy and innacurrate their entire industry is...

others above talking about how they threw a party when the guy that would draw detailed walls retired... wow so you admit you make innacurate plans and literally make fun of people that... oh i dont know... USE MATH? you admit you do things MATHEMATICALLY WRONG and are proudly stuck in your ways...

put simply anyone who uses autocad and not revit is stuck in the 90s... get with the times... revit you can click 2 buttons and have every wall in the building switch between 2x4 w/ 5/8" sheetrock, 2x6 with 5/8" sheetrock.. account for 3/4" plywood and siding and immediately have every exterior wall align with the foundation at the studs... so in a sense yeah i dont blame the above autofags for celebrating when the guy that drew detailed walls retired... because he was insisting they use autocad to draw that... which would be utter hell on earth

Non Sequitur

What a fucking wanker. Not only are grossly misinformed (i.e. Ignorant), you just ranted on a 13year old thread.

How big is a 2x4?

Non Sequitur

38x89mm.

38x89mm, wet or dry?

Non Sequitur

Medium moist?

As opposed to medium damp?

tintt

3 5/8" metal studs with 5/8" gyp each side is 4 7/8". (I did that math myself.)

On the fence

Damn, what a tool. 13 year old thread on wall dimensioning. I'm thinking Russian troll that just lost his job.

josephamodeo

I mean... how am i wrong... most residential architects I have dealt with would just give exterior walls a random thickness of like 7 inches... like "exterior walls are fatter than interior... but by how much... beats me!! heres a random fatter wall" and even worse is... they WOULD ALIGN THE EXTERIOR WALL FACE (SIDING)... WITH THE EXTERIOR FACE OF THE FOUNDATION... thats just plain wrong... the exterior face of the foundation aligns with the wood studs... and the plywood and siding extends past the foundation face... this combined with giving exterior walls a random thickness... is going to completely screw with the interior room dimensions... AUTOFAGS PLEASE CLEAR THIS UP FOR ME... because when the house is built... those dimensions interior dimensions measure differently and a stairwell turns out to be 2' 9" instead of 3' 0"... but for some reason the plans are approved because it said 3' 0" on the plans... WHY NOT JUST MODEL WALL THICKNESS IN REVIT... oh yeah leave that to BIM managers working for the contractor... its their problem... not a rant... im honestly curious and also just sharing my opinion on a COMPLICATED INDUSTRY... also... i was talking about 2 x 4 which is basically 3.5" thick... its pretty rare in my area to build a house with 3-5/8" metal studs... usually massive steel I beams for some kind of experimental storm resistant modern house or something... (i live in a hurricane sandy area)...

SneakyPete

I think the hurricane sandy area is in your pants my dude.

citizen
• F.O.S., F.O.M., F.O.C. + wall type schedule + "hold" and/or "clear" and/or "finish" at critical locations
citizen

^ That, too!

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