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Landscaping & Design/6x6 Cedar Post - Structurally sound?



Good afternoon!

I'm working on the design for a fence...and I've almost made up my mind.  The kicker is what size fence posts to use.  My choices are an 8x8 cedar post or a 6x6 cedar post.  Obviously, the 6x6 is cheaper and, personally, I think it will look aesthetically more pleasing next to the 6x6 posts that are on my pergola over the back porch.

My question.  I plan on mortising, in the middle (actually, offset slightly to allow for the pickets), for the 2x4 runners.  Let me throw some measurements at you:

Mortise in 2" on each side (maybe only 1.75").  This leaves either 2 or 2.5 inches in the middle from one direction.  I'll mortise in  1 7/8" from the rear and 2 5/8" from the front (my picket size is a full 3/4").  Thus, at three spots on my 6 foot cedar post I will have about a 2x2" "weak spot".  

What do you think?  Is that structurally sound?  If not, I could go with the 8x8; however, I'd much prefer the 6x6.

Thanks for any advice you may have!  I mainly just want your honest opinion :).  FYI - I'm also an expert on Allexperts...Microsoft Excel forum.


By allowing 1-3/4 inch for each 2 by 4 rail you will have a total of 2-1/2 inches of free space in which to adjust the location of the rails. I would just locate the rails through the center of the 6 by 6 posts if the offset you mentioned is not critical to the design. A 6 by 6 post can accomodate two 2 by 4 rails without any loss of strength. Offsetting the location of the rails should not be a problem.

You have chosen a good way to construct a fence and you have chosen a good material,cedar,which is highly resistant to rot and is produced naturally. The mortise method of course requires no fasteners and is actually stronger than other connection methods. Good luck. I will check out your post on all experts.

Mark Harshman  

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Design of landscape structures and design of planting arrangements in the landscape. I usually do not answer questions of a horticultural nature or about growing plants or gardening unless they are related to design. I will answer these questions at my discretion. I will answer maintenance questions at my discretion,usually when they are related to design. I am a landscape designer. I am not a contractor or a gardener. Although I will describe how something is built I do not provide detailed installation or construction instructions. Here are example categories of problems I can help you with: Design of residential walks,low walls,low retaining walls,fences,drainage systems,arbors,plant selection,xeriscapes (low water use landscapes),rain garden design,rain water harvesting,permeable paving,sustainable drainage. No advise on an architectural or engineering level. I DO NOT PERFORM ACTUAL DESIGN WORK THROUGH THIS SITE. I only provide suggestions and advice. For more comprehensive help check out my website at:


Landscape concept plan for a 30,000 square feet housing site. Involved site recon by pace measurements and photographs and a site analysis and a site analysis report and recommendations and a preliminary cost estimate. Design elements included canopy trees,shrub cover,accent flowers,trash receptacles,benches and planters. Landscape concept plan for a 7,000 square feet site for a community center. Involved site recon by tape measurements and photographs,a site analysis and the creation of 3 conceptual designs for the site. Work was done through a local professional design center. Design elements included tree garden,playground,sitting area,lawn,cooking area,lighting and concrete and brick paving. Landscape concept plan for a 3,000 square feet housing site. Involved site recon by tape measurements and photographs and a site analysis. Concluded in 3 concept designs for the site,shown at a formal presentation,a site analysis and recommendations. Work was done through a community volunteer program. Design elements included decks,a playground and fencing. Briefly as draftsman for landscape designer/gardener. Conceptual landscape design for residence. Involved site recon by tape and pace measurements and site analysis. Design included covered patio area,ground cover and flower beds. Two years experience as draftsman for transportation department in engineering firm and for engineering consultants to phone company. Duties consisted of plotting topography. Survey crew member. General assistant to surveyor. Work was done for U.S. Army and County Highway Department. No instrument work. Duties included tape measurement,holding graduated survey rod and plumb bob for sighting and clearing brush. Marketed Landscape Design Services. Brochure writing,promotional material and marketing graphics.

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From Civil Engineer: I am very impressed with your work and with the obvious thought you have put into the marketing of your venture. It was especially good to see a print of that job we discussed on the phone. I wish you much luck with the venture as I do with your plans for school. Im darn proud of you buddy. And by the way,when I get my license,maybe you will consider me for a consulting job down the road. I hope to get together with Rick sometime soon and I would really like to show him your stuff if its ok with you. From all these questions you ask I get the feeling that you are genuinely interested and have put alot of thought into the idea and process of landscape architecture and if you could possibly afford the cost I would urge you to take some classes in the areas you are most interested in. The subject is not so simple as it appears,mixing science and engineering with art and a certain amount of religion to create a comfortable and pleasing balance between man and nature. A thoughtful soul like yours can do this but it can be a lifes work getting it right.

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