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I have about 16 panels of merbau batton screening that I want to attach to the front of a concrete block wall at the back corner of my courtyard. The screening is 300x1800 in length, 800 of which I’d like to extend beyond the top of the wall.
Because the screening will be almost 50% above the wall, I’m planning on building a frame to support the screen.
I have considered drilling into the wall from above and adding epoxy or concrete set rebar, so I can bolt down post anchors.
there are things I’ve probably not considered so I am looking for advice and cautionary tales for this project before I dive in! Thanks all!
The current wall is concrete/bessa/cinder block. I believe it’s concrete filled. It is one block in width, and the bottom 500 or so is retaining wall.
After adding the screening, the fence will be 1750 tall on the neighbours side, and on my side it will be 2200. This is because the neighbours side of the fence is 500 or so elevated above our yard.
Here’s some drawings to help explain.
Hi @Phil1982,
I think the most important factor to consider here is how you'll securely connect the frame to the wall. While building the timber frame itself is fairly straightforward, the real challenge lies in ensuring it's fixed down solidly—especially since around half of the screening will sit above the wall, adding leverage and wind load.
You mentioned using epoxy or concrete-set rebar to mount post anchors into the top of the wall, but this approach really depends on whether the wall is fully core-filled with concrete. If it's hollow, anchoring directly into the top might not provide enough structural support. Even if it is filled, it’s generally not as stable as attaching to the front face.
What I’d suggest instead is fixing a frame to the face of the wall, which will give you more fixing points and a sturdier result. Since your wall has capping blocks with a recess, you can create a timber frame that sits between the wall’s columns and capping using 35mm treated pine. These can be dyna-bolted directly into the Besser blocks. Then, you can either notch out the top capping to allow for vertical 70x35mm timber uprights to pass through and extend beyond the wall, or simply fix a second length of 70x35mm timber to the base pieces to create an extension up to your desired height.
Once your upright frame is in place, you can then attach your Merbau screening panels to those vertical and horizontal sections. This approach keeps all your fixings on the stronger front face of the wall and allows you to spread out your load-bearing points, making for a much more stable and durable structure overall.
Please let me know if you have any questions.
Mitchell
Thanks so much for your thorough response.
So to understand, the best approach would be to frame up the screening on the face of the wall. That makes sense to bring the screening forward of the coloumns and lip of the capping.
I've drawn up what I think you've described, with the red X showing the notches i'll need tho chop out of the capping :
The issue I see coming up is the right end of the screening will have more frame above than below the top of the wall. But maybe it won't be an issue...
Hi @Phil1982,
I don't believe it will be an issue with uneven frames, but at the same time, I think it would be possible to increase the height of the last frame at the end so that is in-line with the height of the second to last frame. This will limit that unevenness in the timber frame.
Please keep us updated with your progress, we look forward to seeing your frame built.
If you need further assistance, please let us know.
Eric
