ᐅ Fence Construction – Installing Posts on an Uneven Sandstone Wall?

We have a sandstone wall made of thick, irregularly split blocks. It looks great, but what is the best way to install our fence there? We have standard welded wire mesh panels with corresponding posts for screwing on. Has anyone faced this challenge before? On one hand, the stones are not all the same height, and on the other hand, the relatively small base plate sometimes sits unevenly on the irregular stone surface.

First, I would stretch a string line and make sure it is perfectly vertical.
Then, position the posts, drill the holes, and as shown in the drawing, do not fasten the posts directly to the concrete or stone. Instead, use a nut to lock them from the opposite side. This allows you to properly level the posts. I assume there are four holes per base plate.
Finally, fill the gaps between the base plate and the masonry with mortar.

Hi,

My suggestion:

Mark the outline of the feet on the sandstone and lightly (level the depth) mill into the surface to the size of the feet. Of course, mill rounded instead of square like the feet :-/

Sandstone is quite soft (I have plenty of it at and in my house).

This will probably look better and isn’t much more “fiddly.”

The only open question is where the water (if any) drains from the small recess.

But water evaporates quickly on sandstone, and if the feet are made of stainless steel or well powder-coated, hopefully that won’t be a problem.

zapp

superzapp schrieb:

..... slightly mill into the surface (leveling the depth) .....

I see – that might be manageable for a single post.
But if you have to bring 5 or 10 such posts to the same height, the task becomes quite challenging.
Now here’s the best part:
How do you ensure that a hole or recess in a cavity in the stone is perfectly aligned on three axes (height, left/right, and front/back)?
Sorry Superzapp, but your suggestion doesn’t reflect practical experience.

Hello

I would also use threaded rods, nuts, and washers made of stainless steel. Adjust the threaded rods to the approximate height first and finish them at the top with a cap nut.

Olli

Neubi-BY schrieb:

So, so – with one post, that might still be funny.
But if you have to bring, for example, 5 or 10 of these posts to the same height, the task becomes quite tricky.
Now here’s the best part:
How do you get a hole or recess three-dimensionally aligned (height, left/right, and front/back) perfectly vertical in a hollow in the stone?
Sorry Superzapp: But your suggestion has nothing to do with practical application.

What I mean is: a "mini router table" with 3 adjustment screws with very small tips (can be self-made in a maximum of 1 hour) … level it on the stone (using a spirit level).
Then place a small old router on it (I recently bought one for 15 Euros at a flea market) — position it — rout (with a depth stop to keep the depth consistent since the router table is leveled) — done …

Overall, this doesn’t take any more time than aligning EACH base with adjustment screws.
Also, this way, I lose some bearing surface. That means the bases don’t rest fully on the wall but only on three or four screws. This makes it “wobbly” and at least significantly reduces the bending strength of the post.

Changeling schrieb:

… the comparatively small base plate …

Especially important with the mentioned relatively small (how small?) base plate.

The more I imagine this visually, the less I consider any other solution, both visually and technically.

Alternatively, create a small flat surface under each base (all at the same height) using a two-component adhesive / resin (of course with a suitable material).
But I believe my above solution is better.