Wooden fence on top of concrete block retaining wall.

[boxofrabbits]

Hey gang.
We've just had a wonky single skin brick retaining wall replaced with concrete blocks. Basically the fence came down in a storm and the retaining wall behind it was at such a funky angle we decided we needed to replace it before putting the fence back up. Could literally pull the wall down by hand.

We want to put a 5ft wooden fence on top of this new block wall. I'm trying to find what the best way to do this would be. I'd rather avoid going posts down into post mix in the dirt as that will bring the fence forward in front of the wall and I'm very keen to have the fence panels in line or pushed back from our side of the bricks.

My preference would be 100mm (by about 170cm tall) posts mounted on post shoes directly into the top of the blocks, but I understand theres the potential for structural issues? Is there any reason that this might be a bad idea?

 

[boxofrabbits]

For reference this is what the original wall looked like.

 

[boxofrabbits]

I'd always planned to just use 100mm post shoes with bolts going down into the concrete blocks, but after doing a bunch of research I feel like I understand thats not a great idea?

 

[JohnD]

If you fasten a 6 foot lever to a wall, you can use it to break the wall and pull it over with little effort.

You need to go into the ground.

Put them behind the wall.

A concrete spur set in buried concrete will be suitable and you can bolt a wooden post to it (not in contact with the ground) if you want. Or you can use concrete fence posts. Wooden posts in the ground will rot.

 

[boxofrabbits]

If you fasten a 6 foot lever to a wall, you can use it to break the wall and pull it over with little effort.

You need to go into the ground.

Put them behind the wall.

A concrete spur set in buried concrete will be suitable and you can bolt a wooden post to it (not in contact with the ground) if you want. Or you can use concrete fence posts. Wooden posts in the ground will rot.

Ace thanks. Do you reckon we could do concrete spurs in the ground up against the wall and then have the posts sitting on top of the wall but bolted to the concrete spur? Effectively using the wall as a gravel board?
I'm quite keen to have the panels plum with the wall.

 

[JohnD]

Yes.

 

[ETAF]

yep, thats what we have
small retaining wall about 3ft high - which had a fence ontop - and came down in the wind - so i rebuilt the fence
I used a long 97 mm x 47 treated material - that went down into the ground
and then another piece infront of that , cconcreated into the ground - 2 coach bolt through the 2 pieces and through the wall
then the fence panel is mounted behind the post and i put 10mm spaces on the wall - so the panel was above the wall and not sitting on

did most just before and during 1st lock down

 

[boxofrabbits]

yep, thats what we have
small retaining wall about 3ft high - which had a fence ontop - and came down in the wind - so i rebuilt the fence
I used a long 97 mm x 47 treated material - that went down into the ground
and then another piece infront of that , cconcreated into the ground - 2 coach bolt through the 2 pieces and through the wall
then the fence panel is mounted behind the post and i put 10mm spaces on the wall - so the panel was above the wall and not sitting on

did most just before and during 1st lock down

Do you have any pics mate? I'm struggling to picture what you've described and would love to see it.

 

[ETAF]

hows this - is very wet and windy at the moment - near to coast
for scale the fence panel is a standard 6' wide by 3' high
I soaked the posts in preservative before concreting and made sure the concreting was above the ground level and that it was slopping away , so water would not pool around the post

I used furniture blocks to lock in the Panels - so i could undo from my side and lift the panel away , slide to the side and then bring out

the fence orginally had very small bolts and just one small piece of post bolted to the wall - and used the top course , so luckily in the high winds we get the wall was not damaged - i replaced with 10mm coach bolts and also concreted into the ground the back post against the wall goes down to the wall foundations and the one in front goes much further into the ground probably 18' to 2' and i used postcret and made sure it was well around the Posts .... as i say done around before covid - cant remember exactly - and we have had very high winds since