Door sizes

Page 1 of 3  
Exterior door measures 35.5" wide. I assume this is a nominal 36" door? Or, a bastard size acquired by developer when the home was built?
(A neighbor's door is 31.5" wide which I would assume qualifies as a 32" door]
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/28/2016 09:12 PM, Don Y wrote:

FWIW, my exterior doors measure 36". The doorway openings (weatherstripping to weatherstripping) are 35.5".
I have no idea how my neighbor's doors measure up. ;-)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 3:09 AM, bob wrote:

Thank you, that's exactly the answer I was looking for. I.e., that doors aren't like "dimensional lumber": nominally a particular size (e.g., 2x4) but, in actual fact, somewhat smaller (1.5x3.5).

Seeing ours at 35.5, checking a neighbor's (different floor plan, different building construction, different "nominal size" door) seemed a quick way to the truth.
I'll bring a tape rule with me tonight and ask friends if I can measure theirs to see if the pattern extends to all homes in the neighborhood (the area was developed in two very distinct time periods), all homes of particular styles/floorplans, all homes by a particular *builder* (I think three different developers were involved), etc.
A sample size of TWO (out of two examined) undersized doors isn't very conclusive...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Take your tape to Home Depot or Lowes. What size are those doors? (the ones for sale, not the ones you walk through at the front of the store)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 8:10 AM, TimR wrote:

That will tell me what they *sell* but won't explain why the two doors I observed (different homes, different widths, different construction techniques) are "off". I would find it hard to swallow that an architect drafting (at least) two different plans had to resort to trimming 1/2 inch off of doors in each case.
Did *he* not know what standard door sizes were?
If I can't buy a 35.5" door, then I'll have to alter the frame to accommodate the slightly wider door (a fair bit of work).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, February 29, 2016 at 10:36:32 AM UTC-5, Don Y wrote:

You didn't say if you were looking for a pre-hung door or just a slab or a slab and a separate jamb.
Whenever I have ordered pre-hung doors I gave them the RO measurements and they told me the maximum size door that will fit that RO. Since the doors are pre-hung, they use the RO measurement to determine the size, factoring in the width of the jamb.
Granted, I haven't bought a door from a home center, I go through a local contractor supply house where I know sales person. In any case, the RO measurement is a better number to use than the width of an existing door. I'd be surprised if even a home center staff didn't ask for that measurement. Once you know that options based on that number, you can decide the best course of action.
For the basement steel door, the custom size I needed (height-wise) was way more than I wanted to spend, so I ordered the next taller size, slapped a metal cutting blade in my circular saw and let the sparks fly.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, February 29, 2016 at 10:36:32 AM UTC-5, Don Y wrote:

If all doors are 35.5, then you have determined that a nominal 36 door is actually 35.5.
I find it unlikely a custom door is a half inch different.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 9:59 AM, TimR wrote:

That was the point of *asking* -- instead of surveying the entire neighborhood!
Bob's upthread assertion that *his* door is 36 inches suggests either *his* is the oddball (being EXACTLY "as advertised") *or* mine at 35.5 -- and neighbor's at 31.5 -- are the oddballs!
I find it hard to believe that an architect (multiple architects?) drafting plans for different homes (floor plans, construction techniques, etc.) would be off by 1/2 inch "more than once".
So, did the builder (or, ONE of the builders in this subdivision) get a deal on oddball doors? Did the carpenters and masons screw up reading the plans? Have door dimensions changed over the years? etc.
Now, it's a "local" *puzzle*! I'll have to see how extensive the "problem" is among my other neighbors' homes (I walk past all of them each day; I *don't* drive to Home Depot every day!)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 29 Feb 2016 10:24:45 -0700, Don Y

Dunno, I just checked the 36" door that I am using for a work bench and it is 36 but my 32" doors are all 31.5. I guess Reagan was right, trust but verify.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/29/2016 11:24 AM, Don Y wrote: ...

...
I venture none of the above...as another noted, doors are spec'ed by RO and nominal dimensions; the various manufacturers have always had slightly different precise measurements on prehung units.
I suspect if you'll measure you'll find the finished opening into which the door fits is precisely 3-0 or whatever the nominal is and the door slab itself is undersized to match the particular weather-stripping system in use.
Built-in-place door frames and jambs generally will have a full-size door slab and the opening will then be somewhat larger than nominal to fit.
Tract housing, even more "up-scale" than just starters 40-50 years ago likely was using prehungs rather than custom-built even then although if there's a significant time between the two and the earlier is '50s or so, chances go up on custom framing.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, February 29, 2016 at 1:46:19 PM UTC-5, dpb wrote:

Thank you for joining the RO discussion. I'm not sure why that isn't the *only* thing being discussed. Trying to find a slab to just drop into an existing jamb may end up being more work than just buying a pre-hung door, with modern weather stripping, etc. At a minimum the options for a slab that fits are going to be more limited than the vast selection of per-hungs.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Modern doors are always about 1/2" narrower than their listed size. There has to be some gap around the door, and that 1/2" is your gap. The INSIDE of the frame is the listed size (32" 34" 36", etc).
If you're replacing an entire door and frame, you need the OUTSIDE measurements of the frame, an you make your rough opening about 3/4" larger, so you can align the frame and apply the shims.
Some OLD doors were the actual listed size, but not always.... (Of course back then, the frames had to be 1/2" bigger than the listed door size).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In typed:

You seem to be giving information out about what you want to know, and why, in increments.
Your original post was,
"Exterior door measures 35.5" wide. I assume this is a nominal 36" door? Or, a bastard size acquired by developer when the home was built?"
But later posts seem to indicate that you want to replace your existing door. And, I think you may have also mentioned that you want a metal door for the replacement.
I mention this because if there is something specific that you want to do, it may help to state that. But, if your question is just the curiosity question that you originally posted (and you are not asking because you want to replace your existing door), then the responses and answers would be different.
When I have investigated the possibility of replacing an exterior door in two different older homes, I encountered some of the same issues that you are encountering. In both of my situations, I thought the doors were 36-inch doors. Basically, when I measured the opening for each door, I came up with a 36-inch opening. But, when I measured the actual width of the existing doors, they came up as less than 36 inches wide -- around 35 1/2 or 35 3/4 wide.
Then, when I went to look at doors for sale (just the door slabs themselves -- not prehung doors with the frame included), I kept coming up with doors that were 36 inches wide. That meant that if I bought a new wooden door, it would be 36 inches wide and I probably would have to trim it slightly to make it fit in the existing door frame opening. If I bought a metal door, it would be a problem because trimming 1/4 inch off of the width of a metal door would not be a viable option (I don't even know if it is doable at all).
So, that means that my two options are to:
1) buy a 36 inch wooden door and trim it slightly to fit the existing opening; or,
2) buy a prehung metal door and replace the existing door and frame entirely (which meant more work, dealing with the having to remove the existing trim and frame around the original door etc).
I think that means that the answer to your original question is that, yes, nominal 36 inch exterior doors on older homes were often only nominally 36 inches and were in reality about 35 1/2 or 35 3/4 inches wide to fit into a 36 inch wide opening.
Meanwhile, one of my possible exterior door replacements would have involved a door that is 84 inches high -- not the typical 80 inch high doors that they make now. That would have meant ordering a custom size door. And, since I would be ordering a custom size metal door anyway, I thought that may mean that I could order a custom metal door that was 35 3/4 inches wide and 79 3/4 inches high to fit the existing opening. I never did check to see if I could order a special size metal door with those exact dimensions -- partly because I didn't have the heart to buy a metal door that I only hoped would fit the existing opening correctly.
In the end, I wound up not replacing either door -- at least not yet. I repaired one existing door and I just left the other one (the 84 inch high door) as is and didn't replace it.
Those were my experiencing with this issue in case it helps.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/29/2016 12:54 PM, TomR wrote: ...

You can, yes. You'll possibly not like the pricing options that go with non-nominal dimensions.
I was lucky in TN that there was a local manufacturer in Knoxville who did the job for me for what I thought was quite reasonable -- replacing a wood slab in basement block wall with 4" veneer field stone outside that...
84" is a standard height so you're not as far out in left field as you might think but if you were to try to fit the door in existing opening you've got more than just the actual width/height to deal with--you've got the number, size and location of hinges, height/setback of the lockset, whether there is/isn't additional deadbolt, etc., etc., etc., ...
Miss any one of those details and you're possibly hosed...or at least have customizing to deal with.
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 12:22 PM, dpb wrote:

We've had top go that route with some of our larger windows. While painful, if you're already spending a kilobuck on a window, it's not as distressing to have to spend a bit more to get what you truly want!
[OTOH, a generic $100 steel door doesn't want to turn into a $500 special order with 6 week delivery times, shipping charges, etc.]
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 11:54 AM, TomR wrote:

Because this is EXACTLY what I want to know. I've learned that providing context just invites endless questions that avoid the question being asked (Why do you want to do that? Why do you want to do it THAT way? Why are you obsessing over some trivial issue? Why is this explanation so LONG?? etc.)
I asked the question in much the same way someone ignorant of dimensional lumber standards might ask, "Why are my 2x4's 1.5x3.5?"
Had someone said "Two by four are NOMINAL dimensions -- just like 36 inches is a NOMINAL door dimension", I then would have known that I just need to buy a 36" door and it WILL fit in place of the 35.5" door that I have.

See above. That would inevitably have invited: - what form of home construction - interior or exterior - why do you want steel instead of wood or fiberglass? - will you need to cut a pet door *through* the door? - why not install a WINDOW instead?
Reducing the question to one of "is a 35.5 inch door ACTUALLY what is advertised as a 36 inch door" eliminates all of that discussion.

Exactly. And, I've taken the initiative to not ASSUME that my "sample of one" was representative of ALL such doors -- by walking to neighbor's house and measuring their door (knowing that their house is constructed differently, different door size, etc.). I.e., if THEIR's is also "half an inch undersized", it starts suggesting that this is a question of nominal dimensions being used in place of exact dimensions.
(e.g., people will freely mix discussions of 2x4's (nominal sizes) with 32" and 36" doors -- who's to say the 32/36 isn't also a nominal dimension?)

Exactly.
The same sorts of problems apply to prehung doors as well -- except now you have to contend with the frame, brickmold, etc.

Those are my choices, as well (restricting the discussion to JUST the door -- lest folks want to comment on other unrelated issues that I am not asking about!)

?? 79.75 for an 84 inch door?

The costs of custom -- for a door that is NEVER USED -- are just silly! So, if doors actually ARE 36 inches, then I have to plan on making the opening fit the door.
If I'm going to do THAT, then there are other options that I can bring to bear on the problem that I wouldn't have exercised if I could just install a "drop-in replacement".

Thanks, it basically confirms what I'd feared. Silly to talk to the millworks folks about it as they'll just offer to sell me a custom door.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 29 Feb 2016 13:54:53 -0700, Don Y

Short answer seems to be, take a tape with you and measure the doors. Since we started here I have been measuring all the doors I see and the answer I come up with is there is no standard. I have anything from "right on" to a 1/2" smaller and one that is about 1/4" smaller (steel door so I know it wasn't modified). My guess is that manufactures make doors for standard rough openings and the thickness they choose for the jam determines the actual door size. I am curious how building inspectors deal with clear opening sizes for accessible routes since even a full size door is smaller because of the stops.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 2:18 PM, snipped-for-privacy@aol.com wrote:

That is disheartening. It means having to physically visit each "candidate door" and examine it. Anything "shipped to home" (instead of "pick up at store") is not a viable candidate.

(for PREHUNG doors)

I expect lots of variation on *interior* doors. But, I figured exterior door would have far less wiggle room!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 02/29/2016 3:25 PM, Don Y wrote:
...

Nope as I told you some several responses above...they build to a RO and the final interior opening turns out to be what it is--the two of -1/2" and -1/4" are pretty common for width but the length (height) is also dependent upon those factors plus how they design the threshold.
If you're trying to order a door slab to fit an existing opening, see above as well, there's a whole lot more besides just the exterior dimensions to worry about, especially if you're talking steel, not wood, where field modification is much more of a trick...particularly things like number, size, placement and setback of hinges, hole locations, etc, etc., etc., ...
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/29/2016 6:42 PM, dpb wrote:

My guess is if he can figure out the original manufacturer he can just order the direct replacement. I'd start by looking at Stanley since they are the biggest.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.