View Full Version : Arbor/ Trellis design questions
Dean W.
04-30-2012, 11:15 PM
I'm building an arbor/ trellis and am wondering if anyone can give me suggestions how to build this thing. I have attached a basic sketch of the dimension of what I'm going for. On the right hand side I drove some t-poles into the ground. So far I tied some 2x4s with wire to two of them. My question is should I plant the 2x4s in the ground instead? These are pressure treated 2x4s. If so how deep would it be necessary to prevent the collapse of this thing? I was estimating 12" deep though I could go as deep as 18" and still have enough board left over to equal 6.5' on top. Only problem is digging that deep turns into more and more rocks. So if anyone is pretty handy please advise.
Thanks for looking!
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_Arbor.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=Arbor.jpg)
sunfish
05-01-2012, 07:35 AM
I'm building an arbor/ trellis and am wondering if anyone can give me suggestions how to build this thing. I have attached a basic sketch of the dimension of what I'm going for. On the right hand side I drove some t-poles into the ground. So far I tied some 2x4s with wire to two of them. My question is should I plant the 2x4s in the ground instead? These are pressure treated 2x4s. If so how deep would it be necessary to prevent the collapse of this thing? I was estimating 12" deep though I could go as deep as 18" and still have enough board left over to equal 6.5' on top. Only problem is digging that deep turns into more and more rocks. So if anyone is pretty handy please advise.
Thanks for looking!
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_Arbor.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=Arbor.jpg)
Dean I don't think 2x4s will be rigid enough. 4x4s or even metal pipe would be better for the uprights.
Dean W.
05-01-2012, 07:44 AM
Okay, do you think they might last a few years? I don't really need this to last a long time. I just wanted to build it cheaply.
sunfish
05-01-2012, 07:54 AM
Okay, do you think they might last a few years? I don't really need this to last a long time. I just wanted to build it cheaply.
Treated wood should last at least a few years. I think only the four corner post need to be a little beefier. Even maybe just double up the 2x4s n the 4 corners.
Dean W.
05-01-2012, 07:57 AM
Cool, I guess I'll dig the corner poles then. It will have cross members going across and all the way across on one side. So this should stabilize it somewhat.
Dean W.
05-01-2012, 05:22 PM
This is what I built. Nothing to fancy. Decided to stay w/ the 2x4s they were cheaper. I hope the 1x2 atop the structure can support some weight. I'll add a few more.
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10978.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10978.jpg)
GreenFin
05-01-2012, 11:51 PM
Congrats! Looks like you're making good progress.
Did you dig holes and set the 2x4's into the ground a ways? Did it end up stable enough for you? Hopefully it did, but if not it would add a lot of rigidity to add "X" bracing on the sides. You can use small stuff like 1x2's for it if you wanted.
What I mean by X bracing is this: the long sides of your trellis have 4 vertical posts; if we number them in order 1 through 4 from one end to the other, then what I'm suggesting is nailing one end of a 1x2 to the top of post #1 and to the bottom of post #2, then adding another 1x2 nailed to the top of post #2 and the bottom of post #1, then repeating that process to put X bracing all around it. I think you'd end up with 6 X's: 2 on each long side, 1 on each short side. Or 8 if you put a couple over the roof as well.
That could well be overkill, I don't know, but you'll make it work. I'm looking forward to the pics of it once it's covered in flora :)
Dean W.
05-02-2012, 12:23 AM
Hey GreenFin,
Yes, I put 6 of them in the ground about 13" deep. I think it's pretty stable and can handle the wind and what not. I just don't know about the weight from the vine and fruits that will be on top. Time will tell I guess. I didn't think of X bracing it. That's something for me to consider though it doesn't seem wobbly.
Thanks for the advice!:bananas_b
Scuba_Dave
05-02-2012, 07:30 AM
What is going to be growing on the trellis ?
How long do you expect/want to use it ?
More important then the weight is the effect of wind on the structure once the vine etc grows out
Once the structure has vines on it then the wind force increases & in many cases will blow it over
If you only want to use it for 1 growing season then what you built may work
But a 40-50 mph wind may blow it over
If the 1x2's are reg wood then they will not last long, the grade of wood used to make them is not that great
Also a single nail in each end of the 1x2 shown in the pic will not prevent the structure from moving/swaying
The "X" bracing will greatly increase the strength of the structure
"Fresh" built most things seem stable, its once wind/water & sun start taking their toll that the wood/structure will start to move as time goes on
I use PT 4x4's for (almost) all uprights when I build something, or larger - for my deck
One exception being my greenhouse -but its attached to the house & bolted to a cement foundation
Dean W.
05-02-2012, 08:47 AM
Hi Scuba_Dave,
I only expect it to last a few years. I plan on planting gourds on there. The 1x2s are treated wood. You and Tony are right about using 4x4s. I think I'll check the price on them and maybe reconsider. At least maybe 4 of them.
Thanks!
GreenFin
05-02-2012, 11:19 AM
Hey GreenFin,
Yes, I put 6 of them in the ground about 13" deep.
Probably wise.
Hi Scuba_Dave,
I only expect it to last a few years. I plan on planting gourds on there. The 1x2s are treated wood. You and Tony are right about using 4x4s. I think I'll check the price on them and maybe reconsider. At least maybe 4 of them.
When I made the vertical supports for my greenhouse, I did like Tony suggested above and used pairs of 2x4's screwed together to form my own 4x4's because it was cheaper than buying 4x4's. So rather than buying four 4x4's you could just get four more 2x4's and augment your existing corners if you wanted.
Your trellis looks like it'll be pretty sheltered from the wind. Is that the case, or is it somewhat exposed?
Gourds will look nice on it.
Dean W.
05-02-2012, 12:54 PM
Hey GreenFin,
Yes, I planted those bushes there years ago that act as a wind screen from the North and also provide some privacy.
I went ahead and bought 6-4x4s as per the suggestions I got here. I'll use the 2x4s as cross supports. Already got two holes dug 18-20" deep so I just need to dig 4 more. Then I'll need to line them up and level them a bit. It's a little difficult because it's on a slight hill. So I may use a string with a level.
Thanks for everyone's suggestions. I should have listened the first time, but sometimes we don't want to hear the truth I guess.
GreenFin
05-02-2012, 01:55 PM
That thing might be hurricane-proof by the time you're done with it :)
Scuba_Dave
05-02-2012, 05:49 PM
I actually have over a dozen "spare" PT 4x4's & a few 4x6's
I've taken down 2 pool decks that people were getting rid of & reclaimed the wood
On my greenhouse instead of attaching the 2x4's width to width to make a 4x4 I made an L shape at the corners with the 2x's
Dean W.
05-02-2012, 05:53 PM
That thing might be hurricane-proof by the time you're done with it :)
It should be now and it's a lot of work I hope they're worth it. :ha:
I actually have over a dozen "spare" PT 4x4's & a few 4x6's
I've taken down 2 pool decks that people were getting rid of & reclaimed the wood
On my greenhouse instead of attaching the 2x4's width to width to make a 4x4 I made an L shape at the corners with the 2x's
That's good that you got to reuse some wood. I put an add on freecycle didn't turn up anything, but some 1x4s which I might use across the top.
Dean W.
05-03-2012, 02:27 PM
Finally got the 4x4s in the ground. It may get a little shade in the late afternoon, but I think I should be able to grow them here. Need to nail the 2x4s atop this thing and prepare the soil.
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10986.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10986.jpg)
sunfish
05-03-2012, 03:22 PM
Finally got the 4x4s in the ground. It may get a little shade in the late afternoon, but I think I should be able to grow them here. Need to nail the 2x4s atop this thing and prepare the soil.
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10986.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10986.jpg)
Looks good.
Olafhenny
05-05-2012, 11:42 PM
Sorry, Dean, I am a bit late, but it looks, like you need a bit of engineering advise. As your structure
stands now, I disagree with Scuba Dave that it will blow over at 40 to 50 mph winds. If you put
anything on it, which will catch the wind, such as vines, it will blow over at less than 20 mph. Your
joints at the corners will act like hinges and make the structure fold like a card house, digging the
posts deep will help a little, but not enough.
The very least you will need is diagonal cross strapping. No need to do it across the whole span of
the beams. 3 feet x 3feet from the cross beams to each post will give it plenty of stability.
But if you want that structure to stand up for 10 years or longer, I am afraid you will have to start from
scratch: Dig the post holes about 1 foot deep and at a diameter of about 8 to ten inches. Important
is, that the walls of the holes are undisturbed soil (no lose dirt). Fill the holes with ready mix
concrete. You will need a bag for each 2 to 3 holes. Into that concrete you plant a post bracket
for each post as you see in the top left corner of this site:
post base brackets - Google Search (http://www.google.ca/search?q=post+base+brackets&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=7-ylT9PGPISqiQLVla3sAg&ved=0CGgQsAQ&biw=1920&bih=950)
Make sure these brackets are lined up, sighting from post to post. Having them all the same
elevation will help too. You can ensure that, by using a carpenter’s level and the straightest one
of your 2x4s for the top frame to get them all to the same height.
The idea of the brackets is, that you do not want to have direct contact between concrete and
wood, no matter how well the wood is treated, incised or otherwise. Concrete will make and
wood rot prematurely.
Another bit of advise: Don’t torture yourself by using nails. Beg, steal, borrow or rent a
cordless drill and use 3” special screws for treated lumber. The job will go twice as fast and will
require a lot less foul language to get it done. :)
Good luck,
Olaf
PS: I am adding a couple of pictures from my own gazebo construction eight years ago.
http://www.bananas.org/gallery/watermark.php?file=48711 (http://www.bananas.org/gallery/showphoto.php?photo=48711&ppuser=7269)
You can see, I kept the diagonal strapping a bit shy, but I could afford that, because of the diagonal grid of all the
minor straps.
http://www.bananas.org/gallery/watermark.php?file=48710&size=1 (http://www.bananas.org/gallery/showphoto.php?photo=48710&ppuser=7269)
This is an attempt to blow up part of the previous picture to show the post sitting in the bracket,
which in turn sits in the concrete. It is important, that the concrete is right against the base of the
bracket, for stability, but does not touch the wood.
sunfish
05-06-2012, 12:05 AM
Use galvanized steel post 2' in ground and carriage bolts it will last 100 years
Olafhenny
05-06-2012, 12:39 AM
Use galvanized steel post 2' in ground and carriage bolts it will last 100 years
No it won't. Thin posts like that won't give enough purchase. They will 'cut' the dirt unless set in
concrete to provide a larger surface to withstand lateral force.
Dean W.
05-06-2012, 09:03 AM
Alright here is what I have so far. I really didn't plan on this lasting for 10-100 years. A couple of growing years would most likely be great. I realize at certain times I may have to make tweaks or what not to keep this thing standing. Hopefully it doesn't fall on me while walking under it.:ha:
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10995.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10995.jpg)
Olaf, I really don't feel like redoing this. So I will most likely do the bare minimum and add some cross strapping as you have suggested. The holes range from any where from 18-24" deep depending on the elevation. Really need to get this stuff planted so any other improvements would most likely need to wait till after this growing season. And thanks for adding your pictures as this gives me some clue how to improve this.
Thanks!
sunfish
05-06-2012, 09:08 AM
Alright here is what I have so far. I really didn't plan on this lasting for 10-100 years. A couple of growing years would most likely be great. I realize at certain times I may have to make tweaks or what not to keep this thing standing. Hopefully it doesn't fall on me while walking under it.:ha:
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10995.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10995.jpg)
Olaf, I really don't feel like redoing this. So I will most likely do the bare minimum and add some cross strapping as you have suggested. The holes range from any where from 18-24" deep depending on the elevation. Really need to get this stuff planted so any other improvements would most likely need to wait till after this growing season. And thanks for adding your pictures as this gives me some clue how to improve this.
Thanks!
Sky hooks would help :ha:
The Hollyberry Lady
05-06-2012, 09:26 AM
Great job, Dean! And thanks for all the pictures. :) Can't wait to see how things look for you a little later into the summer. I've always had a thing for arbors and just recently purchased a wrought iron one for indoors. I want to grow climbing roses on a wooden outdoor arbor one day too. I absolutely LOVE the whole look of them...so charming and appealing.
Please continue to show your pics when stuff is growing on your trellis' and arbor. Looks great so far and I just wanted to say congrats. :D
Love yours too, Olaf. Nice work.
: )
Scuba_Dave
05-06-2012, 09:31 AM
I set up 4x4 posts in my garden to support my tomato plants (8'+ tall), peas, cukes etc
The posts are "in" concrete in as much as the concrete was STILL attached to the posts when I dug the hole & put them in the ground
The only cross connections between the posts are the pipes you see which are not braced all that great
http://i767.photobucket.com/albums/xx319/DIYChatroom/Yard%20and%20Plants/DSCF5749.jpg
Once grown in the area is like a jungle
I installed the posts for 2009...so this will be the 4th growing season without any changes/improvements
Its in an area far less protected then yours - since you have that hedge
They have never moved as far as I can tell & there is simply no way a 20 mph wind will blow it over or blow over what you have
http://i767.photobucket.com/albums/xx319/DIYChatroom/Yard%20and%20Plants/Garden08.jpg
I also setup a metal post "square" - white poles- 2nd & 3rd pics, that is not secured into the ground at all
Its not very secure but has not blown over in the past 2 years of use
And there is also the remains of a swing - green poles
http://i767.photobucket.com/albums/xx319/DIYChatroom/Gardens/DSCF7206.jpg
Dean W.
05-06-2012, 09:39 AM
I just went out there and pushed on it some. It moves a little bit. I do have some left over 1x2s (8-8' long + some scrap) which I had planned on adding to the right hand side of the arbor to form a trellis, as soon as I finish preparing the soil.
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC10999.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC10999.jpg)
Dean W.
05-11-2012, 10:20 AM
Update:
I added some "cross straps" finished the trellis part and have planted seeds. It stood up to an estimated 40mph wind gust last night so I think it'll be okay.
http://i232.photobucket.com/albums/ee185/Dean_Wil/th_SDC11005.jpg (http://s232.photobucket.com/albums/ee185/Dean_Wil/?action=view¤t=SDC11005.jpg)
Olafhenny
05-11-2012, 12:37 PM
Hi Dean,
I have no doubt that it will stand up to gusts even quite a bit higher, as it is now. The real concern
sets in, once you have vines or such growing and the wind has something to grab on to.
Good luck,
Olaf
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