Retaining Wall with Fence on Top

[Spinny]

How would people suggest building a retaining wall about 70cm high with a 5-6 foot fence on top ?

 

Blocks need to look good on the neighbours side (low side).

 

Is it better to run wooden posts down through the wall rather than somehow fix to the top of the wall. (Given wind load etc)

 

drainage ?

 

[markc]

The wind load on a 6ft fence can be huge so the dwarf wall would really need to be cast concrete. Use posts for the fence and build the wall in front or around for aesthetics rather than structural

[joe90]

Are you allowed this?

Though the answer may vary from one authority to another, the maximum fence height allowed without planning permission is two metres (6'6”). This two-metre restriction includes any trellising panels that may be erected as part of the fence.

[Gone West]

4 hours ago, Spinny said:

(Given wind load etc)

I've used horizontal hit and miss panels to reduce wind load.

[Spinny]

6 hours ago, joe90 said:

Are you allowed this?

Though the answer may vary from one authority to another, the maximum fence height allowed without planning permission is two metres (6'6”). This two-metre restriction includes any trellising panels that may be erected as part of the fence.

Yes it is on a hill, hence the retaining wall, fence will be 2m on my side. I am quite sure the neighbour doesn’t want me peering over a 3 ft fence on my side into his garden and it is North side so no impact on his sun.

[markc]

2 minutes ago, Spinny said:

Yes it is on a hill, hence the retaining wall, fence will be 2m on my side. I am quite sure the neighbour doesn’t want me peering over a 3 ft fence on my side into his garden and it is North side so no impact on his sun.

But does the neighbour want a 9ft slab of wall/fence to look at? 

[Spinny]

1 minute ago, markc said:

But does the neighbour want a 9ft slab of wall/fence to look at? 

That’s why I need it to look good with some decent blocks for the wall - any suggestions ?

probably won’t be 9ft anyway - maybe 8ft -  or even 7 where his patio is raised up.

TBH could be very nice with some roses or espalier fruit etc grown on his side.

[markc]

1 hour ago, Spinny said:

That’s why I need it to look good with some decent blocks for the wall - any suggestions ?

probably won’t be 9ft anyway - maybe 8ft -  or even 7 where his patio is raised up.

TBH could be very nice with some roses or espalier fruit etc grown on his side.

Good thinking, if you made a nice job of it, made it a feature for them and something they don’t need to maintain then yes it could be a nice touch

[Alan Ambrose]

In a similar situation I did this:

 

+ block wall was already there and fairly secure. Quite big hollow blocks and with some indeterminate mix of soil / concrete in the hollows. Various builders and fencers had had a go at fixing long softwood uprights onto the block wall with super long screws and wallplugs. Average life was a year or so before it blew down / fell apart. It does get a bit of wind sometimes and the leverage on the screws is high.

 

+ decided I would fix this once & for all. Ordered oak posts and rails and OKed a hit-and-miss design with the neighbour to reduce windage. Used resin anchors into the block wall carefully. Can’t remember whether I used the little sock thingies as the blocks were hollowish. Used 3 anchors to mount each post with the ss anchors. Attached rails with ss bolts and little serrated joiny things a fencer mate recommended.

 

+ added the hit and miss verticals. Has been super-solid since 2020 when it was done. A bit of a faff but should last a few decades.

 

+ the neighbour knew they would end up with a deep looking fence. That’s what they had before though and is more or less all you can end up with as our lane is on a 5 degrees slope. They did experience the situation when the fence was down temporarily and neither of us liked the overlooking thing.

 

+ however they’ve put trellis on their side and they grow plants up it and if front of if etc so it doesn’t look bad. In fact it’s obviously better quality than the previous softwood attempts and now they don’t have to worry that the fence might blow down on their 11 year old.

 

p.s. the blocks were already on some kind of concrete foundation.

Edited March 5 by Alan Ambrose

[Spinny]

2 hours ago, Alan Ambrose said:

the blocks were hollowish

I did wonder whether to look for hollow blocks (200mm deep?) and then have the posts run down through the centre of the blocks and into the ground ?

Sounds like you resin bolted the posts to the blocks at the top of the wall using angle brackets ?

 

Ideally I don’t want the wall-fence to be too thick. A normal fence is only 100mm square posts but this has to retain the soil.

[Mike]

5 hours ago, Spinny said:

That’s why I need it to look good with some decent blocks for the wall - any suggestions ?

Then I'd use a structural wall (blocks or in-situ concrete) faced with brickwork or stone.

 

The most robust timber fence that I can recall that wasn't fixed to a concrete wall, was one that used sections of old railway track as posts. They were cast into deep into the ground before the retaining wall was built around them, and didn't look like they or the fence would be going anywhere.