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yogybear_gw

Attaching low retaining wall to fence post

YogyBear
11 years ago

I want to lay pavers to create a patio between my house and a wood fence. The area in question has a slight slope away from the house toward the fence. In order to create a level rectangle for the patio, I would like to do two things: dig it down a little in the highest corner (approximately .5 - 1 ft down) and build a small retaining wall by the fence in the lowest corner (approximately .5 - 1 ft high). The 4x4 fence posts are 8 ft apart, cemented 3-4 ft in the ground. I want the retaining wall to be below the bottom of the fence (i.e., really low and just high enough to raise the slope enough for the patio to be level). My question is this: Would I be able to simply attach 2x6 treated wood to the posts and have that hold the dirt in place? My worry is that it will make the fence lean with the pressure from the dirt. On the other hand, because the wall will be very low, the amount of dirt resting on the wall and thereby the posts will be minimal. Any recommendations are welcome.

Comments (13)

  • aloha2009
    11 years ago

    I'm not an engineer but what you are describing sounds like a garden bed that is commonly seen surrounding a tree. The stones/bricks/pavers are stacked at a slight angle (1/2" ish) to allow for the pressure. Your local HD have ones with the notch in them to guide you in placement. Your wall is so short, the gap created between the pavers and fence should be inconsequential. Good luck.

  • karinl
    11 years ago

    I think one issue here is that your patio will be more permanent than your fence. Your fence posts will have to be replaced at some point, I take it, and won't they have to be dug out? I'm not a big fan of cementing in fence posts for that reason, but maybe it is necessary in your climate.

    I would personally avoid adding this burden to the fence in any case for the reason you mention, and perhaps the manufactured stone mentioned by Aloha is a better option - but I say that as a layperson.

    Some aspects of the gap you will create may, however, be addressed in the thread linked below, where the OP (original poster) faced a similar situation. He had another thread that covered the topic as well that you could find on a search of the forum. I'd prefer to make a gap big enough to weed in if I have to have one at all. And a way to keep fallen leaves etc out of it.

    The ideal solution is probably a poured concrete wall under the fence, but like in Sammy's case, I guess it's too late for that.

    Karin L

    Here is a link that might be useful: one thread by Sammy

  • YogyBear
    Original Author
    11 years ago

    I have posted a picture here and will post another one that shows the slight slope a little better. The slope is on the left hand side closest to the camera. The intention is for the patio to be between the concrete sidewalk and the fence running the length of the sidewalk (appx. 16x20ft). There is a gap under the fence varying from 4-0 inches, and I wish to maintain a gap of a couple of inches all around.
    I went and read through Sammy's situation as suggested and this was quite informative. I had not considered the issue of longevity of the wood. On the other hand, if we were able to get 10-15 years out of it (as was suggested) before needing to repair it, we would be ok with that.
    To give a little more information: we are in Nova Scotia, Canada (zone 5b), so we get a fair bit of frost and snow as well as warm somewhat humid summers. The soil around our property is very sandy, so it drains very well. The patio area is south facing.
    Another thing I read somewhere online was that the posts for this kind of retaining wall should be 4 feet apart. If that is the case, I could take out the fence panels and put down additional posts. Not sure this would make a difference.
    I have never heard about the manufactured stones Aloha mentioned, and I'm having a hard time picturing it. Would you have a picture? We're trying to keep the cost low, which is also the reason we thought about the plank-style retaining wall.
    I appreciate any advice you can offer.

  • YogyBear
    Original Author
    11 years ago

    Here is the picture.

  • YogyBear
    Original Author
    11 years ago

    Here is a picture that better shows the slope on the left hand side.

  • PRO
    Yardvaark
    11 years ago

    Yogy, there is no need for retaining walls here. Incorporating them would only add complication and expense to your project, create a less desirable patio than otherwise could have been had and lean toward "junking up" the appearance...simply because they are uneccessary. At most what you need to do is rework the bottom of the fence at the side where the gate is to make it accommodate the new patio grade. It would be much easier to construct a patio like this if the fence was not in the way. If you can disconnect the fence panels and move them out of the way while the patio is being built it will be a big help. The posts can stay and will not be a problem to work around. You'll need a 6 1/2" - 7" depth excavation in order to accommodate all the layers that comprise the paver patio. It looks like that excavation is already started near the side door just off of the walk. The patio should meet flush the edge of the existing walk unless you intend to do away with the walk. If its surface is in good condition, uniform, and you are content with its appearance, there's no need for you to remove it. The soil that you excavate can be used to retain the patio at areas where there is a dip in the grade. It can be used to blend the grade and fill in any other areas where you need it around the yard.

    When doing a project like this you must figure out all the drainage ahead of time. Your pictures don't show the other side of the fence and what's behind the camera. One picture suggests that the grade falls off in the direction of the camera. Just make sure that all the water that falls on the patio will have unimpeded access to lower ground so that no water pools. If you think any of it is questionable, you should add more pictures that show an expanded area where the pictures explain the conditions.

  • YogyBear
    Original Author
    11 years ago

    Ok. I see what you mean. The pictures were a little misleading. I've attached another one. The walk is actually higher all the way except at the corner closest to the camera, where there is a "bump" in the ground. The idea would be to walk down from the walk to the patio, not to have the patio be flush with the walk. You are correct that the ground slopes off toward the camera and this is also the case on the other side of the fence, so drainage should not be a problem.
    It would be great not to have to build a retaining wall at all. The plan was to have the patio all the way to the end of the walk, which is about equivalent to midway through the third fence panel, at which point the grade slopes more, but with what you're saying, I'm wondering if we're better off making the patio a little smaller if this would mean not needing the retaining wall.
    This is really helpful. Also the depth for the excavation. I really appreciate your feedback as we're complete newbies at this sort of stuff.

  • aloha2009
    11 years ago

    It may help if you took a measurement of the slope to determine better how many inches of slope you are dealing with. Don't forget to add the 1/8 - 1/4" slope that the patio is to slope for proper drainage.

    You might consider doing a large exit/entry step and have the remainder of the patio one step down.

  • PRO
    Yardvaark
    11 years ago

    If you were designing from scratch and no sidewalk existed, would you create a patio with a raised walk along the house edge as you are proposing now to construct? I doubt it. A large entry step as Aloha describes seems fine, but "large" would likely be wider than your walk is presently. Your proposal is "making do" as the walk already exists. In most cases, extending the patio all at one level would be preferable (if it's possible and I think it is) and second choice would be in creating that large entry step and a single lower level. 3rd choice would be your proposal of the existing walk with a lower level patio. For the purpose of designing the patio, I would temporarily forget about the existence of the fence. The patio is a much more major element and the fence should change to accommodate it, if necessary. However, I doubt there'd need to be much change, if any... depending on what you come up with.

    In order to discover what grade you're actually working with, use an inexpensive line level and some masonry string to measure the vertical distances of the proposed patio corners. In the picture that labels the corners "A,B,C,D"... "A" is presumed to be the highest elevation. If it turns out that "D" is highest (but I doubt it) make measurements from there instead. You're looking for the vertical difference between the highest corner ("A") and all the others. Also, determine the horizontal distance between "A" and "B" ...And between "B" and "C".

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  • aloha2009
    11 years ago

    I missed the part of the walkway remaining.

    I have a preference for a wider entry/exit area but I was thinking more on the lines of 6' wide perhaps not the length of the current sidewalk.

    Upon Yard's recommendation and reviewing the pics, I can see that his #1 recommendation would well work too. Adding onto the current sidewalk IMO will always look like a patch job instead of a well thought patio. Yes you are giving it thought but for a just a little extra money, it could look great.

    Thanks Yard for providing such an easy way to measure the grading. We've been doing it with 12' boards. Your way is so much easier, faster and more accurate.

  • YogyBear
    Original Author
    11 years ago

    I really like your instructions on how to measure the grade. I will go get a line level this weekend to try to figure it out.
    We had not really planned on removing the walkway. It runs along the side of house the whole way to the front where it ties into the steps down to the sidewalk. We also are not intending to change the fence as we built that only two years ago.
    We're trying to avoid this becoming a big job as this would prevent us from doing anything at all (the reason other jobs around the house are waiting until we are ready to go "all in"). If we end up staying in this house in the long term, we would likely want to redo the patio down the road. For now, we want to create an outdoor space for an eating area and to eliminate the "sandbox" that is outside our house because our dogs drag a dustpan full of sand into the house every day. So I guess you can say we are looking for a "make do solution".

  • PRO
    Yardvaark
    11 years ago

    "We're trying to avoid this becoming a big job..."

    I didn't think you intended to remove the walk and not suggesting that you do. If you can live with the Euro-mix-and-match, I'm not opposed to your doing so. I'm suggesting that if you had a clean slate with no existing walk or fence, you'd probably create a simple one-level patio... not the step-down situation with retaining walls that you automatically seem to be jumping to. Think about just adding on to the the existing walk as though it were part of that single level. Not saying you can't do a step-down, but then I'd be gravitating toward Aloha's suggestion of expanding the width of the existing walk near the entrance area and then stepping down. Otherwise, the entrance area level would seem skimpy. It would be a little more effort, but it would also tend toward working well with the existing left run of fence. However, I think you're going to need to do a little remodeling of the lower edge of the fence along the gate run. But it would not be a big deal so should not scare you or bring your project to a halt. After you determine the ACTUAL grade differences at the proposed patio corners, it will be easier to know what is possible and reasonable.

    While using the line level keep the line taught. (Glad you can use it, too, Aloha!)