Front yard retaining wall
September 5, 2018 6:34 AM   Subscribe

I am replacing the fence in these pictures with a new picket fence, but the yard is 4 to 8 inches higher than the sidewalk. The fence company does fences but not landscaping, so they want to remove the current fence, put in a new fence, and leave enough room for me to add a retaining wall afterward. Is that the best order to do things, and what kind of retaining wall should I build?

Really this is two questions: first, I'm not sure how to handle the sequence of "remove fence, install retaining wall, install new fence" given that the fence company wants to do steps 1 and 3 during the same visit. I'd rather have them do the work of removing the current fence, but if it's better to build the wall first I could probably remove the current fence myself.

Second, whatever the sequence, how do I build a retaining wall? I'm just looking for a simple, reasonably attractive way to stop the front yard spilling into the street.
posted by john hadron collider to Home & Garden (12 answers total) 1 user marked this as a favorite
 
If it weren't for that giant tree, I would say that the best solution would be to remove the existing fence, then grade the yard so that it meets the elevation of the sidewalk, then put in the new fence. Grading around that tree might be tough because of roots, though, and you certainly don't want to damage the roots.

My personal preference would be to have a contractor install a concrete retaining wall (think free-standing curb) into which the new fence posts would be mounted. That presents some potential maintenance problems down the line if you need to replace a post, though, since you're likely to booger up the retaining wall in the process of removing one. It would be the cleanest, neatest look in my opinion, though. Metal posts would be the best bet in this scenario.

If the fence contractor wants to do all their work at once, you'd be left having to build the retaining wall back inside the yard by a foot or more, it looks like. I don't know how that would look, but the wall could be stone, or concrete, or whatever you want it to be. That tree may still make the project tricky even if you do it that way. There's not a good way to get around it.

If you do a rock or stone or brick wall, make sure that it's secured somehow. A small footing onto which the stone or brick is mortared would be ideal. Stones set on the ground will eventually move.
posted by Shohn at 6:58 AM on September 5, 2018


Short answer: take the fence down yourself. Have a landscaper build a retaining wall*. Have the fencer build a fence.

It's very difficult to build a retaining wall with dirt behind it that won't just tip over or slide down after a couple of years. When the ground gets wet, the dirt will settle and push the wall outwards. This happens even faster in areas where it freezes in the winter. It's impossible to stop this happening without sinking supports deep into the ground -- or by building a terraced retaining wall. Even a wall made out of cement will fracture and break and tip over if it isn't solidly anchored.

I mean, fortunately, it's less than a foot, so it's not going to cost the world, but if you want it to last and for your new fence to not fall over as the dirt moves too, then get a professional.
posted by seanmpuckett at 7:00 AM on September 5, 2018 [2 favorites]


the fence company wants to do steps 1 and 3 during the same visit

IANBV*, but I think this is the main motive for suggesting what they're suggesting. Their way sounds both less pleasi to the eye and more difficult.

*I Am Not Bob Vila
posted by The Underpants Monster at 7:45 AM on September 5, 2018


This is 100% anecdata, uninformed by any knowledge of proper procedure, but: My front yard looked almost exactly like this, and we built the picket fence first and then came along and did a little retaining wall with those concrete blocks afterward and all has been well for nigh 20 years.
posted by HotToddy at 8:29 AM on September 5, 2018 [1 favorite]


My personal rules for putting up structures say that if it goes in the ground, it needs to be made of concrete; if it goes onto or into concrete near the ground, it needs to be made of concrete or galvanized steel; and if it's made of wood, it never touches the ground at all not ever.

My personal preference would be to have a contractor install a concrete retaining wall (think free-standing curb) into which the new fence posts would be mounted. That presents some potential maintenance problems down the line if you need to replace a post, though, since you're likely to booger up the retaining wall in the process of removing one. It would be the cleanest, neatest look in my opinion, though. Metal posts would be the best bet in this scenario.

Agreed. Except I'd go for square steel posts with welded-on base plates and bolt them into the retaining wall with screw bolts, rather than having them set into the concrete during the pour. That makes them very easy to replace when your local idiot drives his car into your new fence three days after it goes up. Just don't believe that nonsense about being able to install screw bolts by hand with a socket wrench. Not gonna happen. Rattle gun for the win.

I used these kinds of posts and anchors to make the pool fence around our above-ground pool in the back yard, because I wanted something I could eventually remove without leaving spiky bits of metal sticking out of the ground to rip holes in my feet. The posts have been in place for ten years now and show no signs of shifting on their own.

I'd also have the contractor dig a trench so that retaining wall extended below ground. I'd be happy with a retaining wall thickness of maybe a foot, a trench depth about the same as the height of the exposed front face of the retaining wall, and at least two lengths of rebar inside the concrete, say four inches above the bottom and below the top and four inches in from the front. If the trench could be dug with an undercut on the lawn side, so that the bottom of the retaining wall cum footer ended up wider than the top, so much the better.

I'd want a big gap in front of the big tree, on the basis that the tree itself will do an adequate job of retaining soil around its base and I'd rather not damage its larger roots. A separate block footing could be dug and poured for the post at the tree's end of the fence.

If the posts are set back just the right distance from the front of the concrete footing to allow the fence pickets to extend down past the front of it with maybe half an inch of clearance, they can go down to just above pavement level and the whole installation should look very neat.
posted by flabdablet at 8:41 AM on September 5, 2018 [1 favorite]


IANBVE*, but my concern with a solid concrete wall is that if you don't go down below the frost line, the whole thing could heave (and possibly crack.) If your fence is built on top of it you could end with a wonky fence. If you're building your retaining wall with individual blocks that's less of a concern because they have room to move against each other.

You don't specify your climate, so if there's no freezing/thawing going on this is a moot point.

*I Am Not Bob Villa Either
posted by howling fantods at 12:22 PM on September 5, 2018


The change in level is small enough, IMHO that I don't think you need to do any major engineering. It is, after all, more or less being held back currently by old 2x6s braced by nothing more than sagging chain link. While it would be slightly easier to remove the old fence, put in the wall, then install the new fence, I think it would also be possible to do it after the new fence is installed. Here's what I might do in your shoes:
Have the fence contractor take out the old fence and install the new one about 16" back from the sidewalk. They may need to trim the underside of the pickets over the tree roots due to the additional setback compared to the current fence line. This setback will allow for the width of a 12w x 4h x 7d retaining block wall plus an additional 8" of backfill space between the block and the fence (and the reason for that size is that it's the size of a small manual tamper). After the fence is up, dig out a flat level channel ~8" wide along the sidewalk, and about 4" below the level of the sidewalk, and fill with 2" of tamped paver base. Lay 2 courses of retaining wall blocks and add a 2" decorative cap stone, which will give you 8" of total height from sidewalk level all the way across. Fill and tamp down the existing soil first, and amend the top 3" inches or so with some bagged compost. Then you can plant some low maintenance plants in the space between the short wall and the fence. My choice would be an evergreen ground cover like mondo grass or vinca that needs little to no watering once established and will look at least halfway tidy during the colder months.
posted by drlith at 12:40 PM on September 5, 2018


This and this are roughly the idea.
posted by drlith at 1:05 PM on September 5, 2018


You don't specify your climate

Boston, so there will be lots of freeze-thaw in the winter. Although it's been in the 90s this September so who's to say really.
posted by john hadron collider at 1:36 PM on September 5, 2018


The height requirements to need permits for retaining walls can be shockingly low. Like a foot. You might want to check local code. This is something they've gotten much much stricter about over the last 20 years +.
posted by JPD at 2:18 PM on September 5, 2018


Another possibility, since it is indeed only four to eight inches, is simply to remove a bit of soil from behind the fence and shape what remains into a slope no steeper than about 1 in 4. With grass or other ground cover planted over the slope, that should stay put pretty much by itself.
posted by flabdablet at 1:52 AM on September 6, 2018 [1 favorite]


We have a similar setup and have railway ties for the wall. We’re in zone 7 (coastal Long Island), so I can’t speak about your climate, but we haven’t had issues yet. The house was built in the 70s and I believe the wall was original.
posted by snickerdoodle at 8:11 AM on September 6, 2018


« Older Roasting chilies: Paper or plastic?   |   on this night we recline Newer »

You are not logged in, either login or create an account to post comments