Pergola type arbor construction

18 years ago

The arbor I built twenty years ago has begun to list to the east due to the weight of my climbing rose and trumpet vine. Some of the cross beams have begun to deteriorate. I would like to replace it with a pergola type arbor(approximately 4 by 6 feet in size)using fiberglass columns as uprights My local Menards carries these columns, but the staff members were unable to help me when I asked how the columns would be secured so the arbor itself would be stable. I wondered if you would sink a 4 x 4 into the ground (36 inches in our climate) and then slide the column over the 4x4. I would then attach the cross beams above the columns with carriage bolts to the 4x4 and cut it off at the top of the arbor to hide the post.

Would this be the best method? I would have to purchase 4x4x12' posts to sink three feet into the ground below the frost line and still have enough height for the arbor. My friend thought that the posts might not be straight enough and that the columns might possibly lean due to the crooked posts. Would cedar or pressure treated wood be best? Whatever I build, I want it to last!

Thanks,

Rand in Milwaukee

Sort by:Oldest

Comments (5)

oakhill (zone 9A, Calif.)
18 years ago
Just a comment on pressure treated posts. I just installed about 100- 4x4x4 for a fence, starting with 4x4x8, and they were very straight. I do not know the size of hole in the Menards columns, but the 4x4 post are actually 3.5 x 3.5. If the column hole is larger, you would need to add shims to the posts to keep the columns straight. The cedar posts I replaced were very irregular in size and straightness (if that is a word). I also put the posts into a base of post cement so the bottom and sides would not be in direct contact with soil. My trial from 5 years ago showed this helped in preventing decay of the posts.
garyfla_gw
18 years ago
Hi
Have you thought of using PVC pipe set in concrete??
Is the hole round or square in the column?? use as large a diameter of pipe as will fit into the hole and of courdse be sure the pipe is perpendicular before the concrete sets lol. I did that with some fancy roman columns and filled the space between with concrete .In this case the hole went all the way through but was a real pain getting the concrete up there . Of course you could always bolt them together but who wants a bolt head ?? gary
Related Professionals
Florence Landscape Architects & Landscape Designers · Roanoke Landscape Architects & Landscape Designers · Santa Rosa Landscape Architects & Landscape Designers · Santa Fe Landscape Architects & Landscape Designers · Magnolia Landscape Contractors · Rome Landscape Contractors · Portsmouth Landscape Contractors · Auburn Landscape Contractors · Branson Tile and Stone Contractors · San Marcos Tile and Stone Contractors · Coldwater Tile and Stone Contractors · Detroit Tile and Stone Contractors · Saginaw Tile and Stone Contractors · San Diego Tile and Stone Contractors · Great Falls Tile and Stone Contractors
ole_dawg
18 years ago
Use the "Great Stuff" canned foam. It will be easier the concret.

1eyedJack and the Dawg
rand412
Original Author
18 years ago
Thanks for the input. The interior opening at the top of the column is 3 3/4". I guess I would be more comfortable using the wood posts rather than trying to fill pvc pipe with concrete.

I didn't really investigate regular wood columns which they also carry at the store. I figured the fiberglass would hold paint better and last longer. I may go back and read the brochure for the wood columns to see if they might be easier to install. It's just frustrating when you take a plan book to the store to clearly show them your project and even then the employees really don't seem to have a clue about how to install their merchandise.

BTW, I tried to attach a photo of the type of arbor I'm trying to build to my original question, but I don't know how to insert photos into a message.
tomakers
18 years ago
Bring your plans to somewhere other than the big box stores and you might get more help. Most of those employees have never built anything in their lives. Setting pressure treated posts in concrete in pretty close to permanent and should be more than enough for any pergola or arbor.
JMO,
Tom