Porch columns and porch posts support a beam that supports the porch roof.
This may sound very simple but this is a crucial area that is frequently done wrong by carpenters today.
The design is actually very simple yet carpenters continue to mess up a good design.
Here we will discuss two basic types of porch supports: columns and posts. Entire books are written on this subject which is quite complicated but here I will show you the basics you need to know to avoid making common mistakes.
Columns are round and piers are square but we will use the term column interchangeably here. Porch posts however are narrower and the wood is usually turned – exclusive to Victorian homes.
Round columns are based on the Classical Orders of Design. There are features a column must have and strict rules for their exact location. There are formulas to determine the correct proportion based on the height of the column. There must not be any deviation from the rules of a properly designed column. Reputable manufacturers will state that their columns are “architecturally correct”.
Turned Victorian porch posts do NOT have strict rules although there are good and bad designs but that is not important for this article.
A porch column attached to a porch roof beam may seem simple but most carpenters do it wrong.
Starting from the bottom. The base of the column or post must be no wider than the porch pier supporting it.
The top of the column or post must support the base of the porch beam and the shaft of the column or post must be exactly the same diameter of the beam. No exceptions.
The shaft of the column is tapered and the top of the shaft (neck) must match the width of the beam it supports. The capital (top) extends outwards past the beam.
This is how a column must line up to the porch beam.
This is 100% WRONG. The contractor and architect both should end up in a medieval prison in a cold climate.
This is WRONG!! Never do this. This carpenter’s wife should be plagued with runners in her hose for life.
Turned porch posts line up the same way but the porch beam is not as wide. If your original porch posts are missing, you must have new posts milled with the top portion that is square – not turned be the same width of the porch beam. This is an easy way to determine the size of the original posts.
Turned porch posts are at least 4″ thick at the square (non turned ends). This matches the porch beam exactly.
Please ignore the vinyl bead board. I will find an example on a nicer house.
Here is a very good video by Brent Hull on Building Tapered Columns.
You can’t explain it better than this!
The following books are companion books and I recommend purchasing both of them. You will be very happy you did.
Both of these books are equally important and compliment each other – not duplicate.
Both of these books are equally important and compliment each other – not duplicate.
The use of contractor instead of carpenter is more accurate. Any actual carpenter and master carpenter knows how to correctly place these columns and posts, the correct size required, and where to place them. Perhaps the people you’ve run across who claim to be carpenters haven’t actually learned the trade, and therefore should not claim themselves to be carpenters.
On the red column above, is it appropriate to paint an accent color on any of the details? If so, which ones? Thanks so much for all your information!
It depends on the house. If more of an Arts & Crafts then no. Otherwise on a pre 1920 house I would only accent the top and bottom band/ring and the small band several inches below the top band. Use either the body color or the sash color. I usually use the sash color for all accenting. I do this with a dark trim but if a white or cream I recommend not accenting for it will be too in-your-face looking.
“This is 100% WRONG. The contractor and architect both should end up in a medieval prison in a cold climate.”
I absolutely love your humor.
So happy I have discovered you website! We are redoing our porch (1906 World Fair brick house with Tudor gables) by replacing the actual horrifying rod iron vines (!!!!!!) and putting wood pillars. We might book a zoom consolation with you to make sure we will get things right.
Thank you for helping us be aware of how things used to be done and appreciate the true beauty of historic homes.
I am in the middle of a old house porch remodel and am worried.
I did the calculations for the right diameter columns in relation to the height of my porch. In my case a 12” (11 5/8) diameter gives me a 9.5 ratio of diameter to height, right in between Ionic and Corinthian. Good.
The next column size down was 10” (9) and would give a ratio of over 11 and beyond any of the orders. I feel these would be too skinny for my porch.
The problem however is that the bases supplied with 12” columns are quite large and now my measurements indicate there will be several inches of overhang over the porch on the corners. My contractor said we could simply cheat them in, but I fear this will result in your picture above where the capital is not correctly aligned.
Any suggestions? I fear having to rebuy all of my columns, and also fear the next size down may be too skinny. Thanks
I would always go larger instead of smaller but the bases should still have 1″ of porch floor showing at the edge. You may need to cheat a bit but I would contact the column manufacturer for correct sizing is complicated. Sorry for not being able to help. The experts on this are Gary Katz and Brent Hull. You may want to do a search on them.
This seems like as good a place as any other for this question.
Must a brick pier under the porch columns be the same width as the brick piers under the main house?
Exposed brick piers will line up with the base of the porch columns. The only way I can think of piers under the main house is if there is no basement. In this case I don’t think it should matter. Am I understanding you correctly?
I love your site. Please bear with me as I am a mere layperson.
I came here looking for information about columns and their accoutrements. The front and back porches on my 1892 house have smooth columns. In the nomination form for the national historic district where my house is located, dated some decades ago, the author described the columns on my house as Tuscan.
I am in the unfortunate position that I need to replace the column bases. The bases on the front porch columns were in very bad shape when we bought the house a decade ago. A contractor had cobbled together a “solution” that does not solve the equation, apparently using some salvage materials. I need to make so repairs so now is the time to put things right.
The column base on the back porch seems like it might be original, but after exploring the book _Get Your House Right_, I realize it looks like the base belongs to the Ionic order (Attic) rather than Tuscan like the column itself. The house was designed by a prominent local architect with a Cornell education so I should think he knew what he was doing. Another house in the neighborhood designed by the same architect has similar bases on Tuscan columns. It is a mystery as to whether these bases are original or if they were changed out somewhere along the way.
I notice here that your columns look an awful lot like mine, with what I think is an Ionic base on a Tuscan column. Can you speak to this at all? Am I off base on the mix of orders?
Hi – most columns are Tuscon on homes. The Tuscon-Doric and Ionic are very similar. You can purchase good bases only as I did on my house. Schwerds and Somerset Columns are good places and understand what they are doing. You can find them online or in my porch e-book but I don’t believe they have an actual website. Any problem email me with photos. Good luck!
Hello,
I purchased your porch e-book, but don’t see any info or diagrams on column bases. I am making new bases for my 3 1909 porch columns but am wondering where the angle of the slope of the porch floor (which seemed steep like 1/4-1/2″ per foot), is made up to align with a vertical column. Is the square part of the base supposed to have the angle sanded/plained into it?
Also these columns are solid wood, should I still add ventilation through the base to allow any moisture in the column or base to escape?
Do you know of anyone using a layer of plastic like HDPE to separate the column base from the porch floor as a moisture barrier? I am thinking of using HDPE in a wedge shim to make up the angle gap.
Hi – I am surprised the column is solid – that’s a whole lot of wood. If solid there shouldn’t be a need to vent. As for the angle – very good catch – I seriously never thought of that. I would guess that my carpenter may have done some minor sanding for in a 1 foot space the angle is very slight.
Don’t know about the plastic but that should be good. I did see an article once in Old House JOurnal where little metal feet were used. Not sure how that would look – I like your idea better.
How many supporting columns does a porch have to have? Two of our 6 posts on our front porch are rotting at the bottom and need to be replaced. I can find info on specs for decks but not for porches. I see some of our neighbors have gone down to 4 posts and put square columns covers up. I like the look. My husband thinks we need all 6.
Post 1, is against the house, 84″, post 2, 100″ post 3, (doorway/walkway 60″), post 4, 96″, post 5, 100″, post 6.
The width of the porch which is 72″.
We want to remove (and leave off) the railings as the ground is only 6 inches lower than the porch and not necessary. Our porch has it’s own roof.
If your porch is original them replace exactly. You can purchase good bases only at Somerset Columns or Schwerds. No balustrade sounds good.
How can you wrap a porch post that is flush against a garage wall and only 3 sides are exposed?
I wanted to wrap my 3 wooden posts in SQUARE NON-TAPERED DOUBLE RAISED PANEL PVC ENDURA-CRAFT COLUMN WRAP KIT, STANDARD CAPITAL & BASE, but that won’t work for the post that sits against the wall with NO space. Help!
I just looked up the product you mention. Why wrap them – all you need to do is to maintain them. Wrapping them with any product will make the column rot from the inside not to mention a fake look like having vinyl on a house or a slip cover on a sofa.
On our porch, the actual beam is only 5″ wide, but it is trimmed out with a 6 1/2″ wide board attached to the bottom. We are looking to replace the current columns (old, but not original) which have a shaft diameter of 8 1/2″ at the top. Too large, we know. In this situation, would you go with a column with a 6 1/2″ diameter at the top of the shaft?
And in the first 3 photos, do you know the width of the beam? The column looks great on the porch!
Yes – you should be able to modify the beam. Mine is 5.25 wide and 6″ tall
Sorry – we weren’t thinking about modifying the beam, just asking if in choosing the correct size column should we be considering the narrowest width of the beam (5″) or the wider bottom width (6 1/2″). I’ll try to include a photo.
Based on the width of your beam, I assume the diameter of the top of the shaft of the column is approximately
5.25″?
/Users/kathy/Desktop/column and beam.pdf
Your beam should be just one width. As shown in the diagram the shaft of the column or post or whatever support must line up perfectly with the beam and not be wider or smaller. Just follow the image I have.
My porch beams are 2 2×8 that stick out 6ft are are spaced 7 inches apart boxed in with osb .I bought 6×6 cedar posts that won’t catch either beam .what do I do?
Hi – this is difficult to understand. Please email me a photo and I can help.