Workshop Interior Doors #2: the MATH

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Blog entry by ~Julie~ posted 02-02-2013 02:14 PM 2051 reads 0 times favorited 7 comments Add to Favorites Watch
« Part 1: the plan Part 2 of Workshop Interior Doors series Part 3: the haunched mortise and tenon »

For the opening between my front room and the larger workshop part, I have about 56” across. I have decided that I just want to use the left door (when looking into the workshop) on a regular basis and have the right door bolted shut most of the time. That way, just for going in and out, I will use the one door. When moving larger objects I can easily use both doors. I’m making two equal sized doors, each with three equal sized divisions. So each door is about 28” wide.

Here’s a basic sketch, not to scale:

For the opening between the workshop and the garage, it’s 70” wide and didn’t appear to be a good size for two equal sized doors because they would be too wide at 35” each. So, I decided to make the left hand door (when looking into the garage) a regular size and the right hand door with almost double the width. The middle rails will all be the same lengths, but an additional center stile will help join the rails. So not actually double, but the interior panels will be the same width on the right hand larger door as on the left hand narrower door. I’ll show how I figured these amounts later.

Best explained by another sketch:

These doors will open into the garage so that they do not block the lumber rack to the right and stocking it.This is the doorway that I will move furniture in and out of and also bring in my lumber supplies. As with the other door, for most day-to-day uses the right side will mostly be bolted shut, but can easily be opened to allow for a wider passage.

As you can see from this photo, if the doors opened into the shop (towards the photo), the right hand door would block the flow of bringing in new lumber to the lumber rack.

Okay now that I’ve explained my thinking in the design… it’s time to do the math.

(I love Mathematics… LOVE. MATH… had to say it…)

I am going with stiles, the vertical pieces, at 5” wide. To figure out the rail sizes (horizontal) I just take the total widths of the door opening and “take away” the number of stiles involved.

NOTE: These are all approximate numbers and I will take into account the spacing for hinges on each side plus a middle gap.

So… for the first doorway, the stiles take up 20” of the 56” so there is 36” left, which means the rails are approx. 18” each (plus the length of the tenons on each end.) But 18” will be showing.

For the second doorway, there are now five stiles, which take up 25” of the 70” width.

We have three sections for the 45” left, not two, so each of the rails will be 15” wide (plus the length of the tenons on each end.) So 15” will be showing. Now because the bottom and top rails INCLUDE the middle stile, I am talking about the middle section rails that are 15” showing.

I hope I haven’t lost any of you…. here this might help:

Whew! Fun!

These doors will be made with 4/4 (“four quarter” or just over 1” thick), 6” wide rough pine that I will joint, plane and cut up. The maximum thickness I can get out of it is 7/8” so that will be the thickness of all my stiles and rails.

For the top and bottom rails on each door I am going to make them a bit wider at 5 5/8” This is the widest amount I can get out of my 6” rough pine to leave me with straight edges. The stiles and other rails are 5” wide.

I will make tenons at 2 1/2” long, so this will add 5” to the length of all my rails.

The next thing I do is make up a cutting list. This gives me the quantity of pieces of each size.
I can then sort through my pine and figure out what pieces I can get out of each length.

For the first set of doors I will have 8 rails and 4 stiles, for the second set I will have 10 rails and 5 stiles. All of this is set out on the cutting list. (I always cut each piece a few inches longer, just in case!) I’ll talk about the panels another time, for now we’ll just deal with the rails and stiles.

The next post will be on getting all the pieces cut…

-- ~Julie~

7 comments so far

View JoeinGa's profile


7735 posts in 1971 days

#1 posted 02-02-2013 03:44 PM

And they told me there would be no math! :-)

These doors are gonna look nice when done!

-- Perform A Random Act Of Kindness Today ... Pay It Forward

View Gpops's profile


248 posts in 3409 days

#2 posted 02-02-2013 10:10 PM

Hi Julie,
Not to screw up your math, as you were enjoying it so much, but have you considered dividing the doorway in thirds and just splitting the rightside door top to bottom with a saw kerf to make it look like three doors instead of the two, I think it will look more symmetrical to the eye than your larger looking door on the right. Kind of like Trompe L’oiel. Cap├ęche ? Don

View NormG's profile


5931 posts in 2968 days

#3 posted 02-02-2013 10:20 PM

Great plan, well thought out to meet your needs

-- Norman - I never never make a mistake, I just change the design.

View ~Julie~'s profile


607 posts in 2999 days

#4 posted 02-02-2013 10:26 PM

Don, I suppose I could have done it that way. It would require a 10” wide piece in the middle though, with support only coming from each side since it would have to run from top to bottom. Anyway, doors are done, so too late, my blog is behind the actual building! Thanks for the suggestion.

-- ~Julie~

View hjt's profile


826 posts in 3103 days

#5 posted 02-06-2013 01:30 AM

Great information. Your hubby must be so proud of the work you do.

-- Harold

View Underdog's profile


1074 posts in 2000 days

#6 posted 02-19-2013 02:14 PM

How much width will be required on your stiles and rails to compensate for trim amount when cutting the tongue and groove, and the outside edge?

Good explanation of figuring door part sizes!

-- "woodworker with an asterisk"

View ~Julie~'s profile


607 posts in 2999 days

#7 posted 02-25-2013 02:13 PM

Underdog – sorry but I don’t understand the question, can you reword it?

-- ~Julie~

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