Hi kudzu ,

I think you are asking for speciifc design details, (which I don't have to offer) but it seems to me you have it pretty easy. If the your house is "stark modern" you just have to consider only the function aspect of the structure. Unlike those of use who live in "older houses" where we have to (should?) be considering how the design is going to fit the exisitng look. You may have found this URL already (http://aggie-horticulture.tamu.edu/extension/homefruit/grapearbors/grape.html) , but it gives some design and function basics. Seems to me you could just build the basic structure, using regular lumber , create some overhangs , paint it, and you're there.

Here's a thought: even in my 20's style house I built a grape arbor up over the back deck using 2" galvanized pipe in concrete for the verticals. I used 2x4 and 2x6 held to the uprights with those U clamps and then built the "roof" with all lumber. That kept the termites in the ground (they'd have to jump up 2 feet to get to the wood!)yet gave me wood to fit together easily overhead.

IF I had been thinking (and bit deep in the pocket as well) I'd have sleeved the pipe verticals with copper pipe before I attached the wood horizontals, and then let the pipe go "natural".

If you have one of those chrome and glass places, you COULD get stainless pipe. (sorry had to throw that in!)

clavero-
Thanks for all the thoughtful comments to get my thinking going. The link was great because I need some construction basics. I am also open to addtiional design ideas that will be clean and simple and go with the house:

I want to build the arbor structure near, but not attached to, the house on a grassy lawn that's not part of this concrete courtyard.

Since you have some strong architectural elements in the existing structure, you might want to consider reflecting these in a strong central structure something like this:



{{gwi:294925}}

Nice suggestion cottgaefarmer! Exactly where my thinking was going when I saw the house pics....(BTW...in my neighbhorhood that is not a house but a resort!)

Depending on your skills, kduzu, you might have to get the plate and rod units fabricated by a shop (stainless is an option remember - GREATLY reduces the rust stain issues)

Also, keep in mind that once the vines get established you are not going to see much of the upper structure from about early May until late October (at least in my coastal hill CA area)

I assume you've thought of cedar, stained or left to go silver-grey as an option for the wood materials?

cottagefarmer-
Nice drawing. It's both simple and consistent with my architecture. Thanks.

clavero-
Again, thanks. That's all very useful and practical info.

I'm building a pergola over my patio and have several grape vines that will grow up and on top of it. Here is my question, because of where we live and the fact that the supports will come in contact with the ground I'm using pressure treated lumber. Will the chemicals used in the lumber be absorbed by the grapes and potentially be harmful for people or animals? If so, is there an issue with just using pressure treated for the supports and conventional lumber, painted, for the top?

divertate-
Interesting question. The way they used to treat lumber was with a copper-arsenate product, and this has been generally discontinued due to toxicity concerns. The new compounds are considered safer, but they still aren't something you should sprinkle on your cornflakes in the morning. Below is a good link that explains this all in a little more detail.

I'm also a little uncomfortable with using treated wood around things I consume, particularly when the roots can provide uptake of the chemicals. You might want to consider some alternatives:

1. Dig large post holes, Pour several inches of concrete in the holes, put the treated posts in the holes and finish the concrete pour. I would think that the migration of the chemicals through the concrete should be minimal, and that there would be relatively little chemical transfer between the surface of the posts and the grape vines. However, if you wanted to be absolutely sure, you could encase the aboveground faces of the posts in cedar boards.

2. Get those steel U-shaped brackets that can be bolted onto the bottom of the posts and set them in concrete footings. That way you don't have to use pressure treated wood at all.

Here is a link that might be useful: Pressure treated wood

If you are (like me) concerned about the effects of using treated timber (cca or otherwise) look for this product instead:
http://www.timbersil.com/

It is apparently more durable than standard treated wood and works by forming glass inside the wood, as if each wood fibre were ennameled. It also doesn't require more expensive stainless or heavily galvanized brackets.

I will probably never trust heavy metal based treatments again, after finding out all the bad stuff that's been covered up concerning CCA. The industry has acted much like the tobaco lobby regarding people's health.

Thanks for the thoughts. It sounds like PT lumber is not the answer at least for this application.

We are considering the same project. We decided on black locust for the arbor. The thought being locust will out last both us and the average life span of the grapes we will plant.

Maybe too late for design ideas, but...this is cedar.
{{gwi:290032}}

I built a frame for my grape vine out of pressure treated wood that i've bought from HomeDepot. I Supported my columns on cement away from the soil, my question is will my grape vine will get affected buy there poisonous chemicals just by resting at top of the pressur treated wood?