ᐅ Cast-in-place exposed concrete entrance platform construction
Created on: 27 Feb 2024 09:38
D
danielg40
Hello,
I would like to create a concrete platform in front of our front door as exposed concrete.
2 x 0.9 m (3.3 x 3 feet) and about 20 cm (8 inches) high.
It should be just a single low step.
Later, I plan to drive over it with the paving stones.
What exactly should I keep in mind?
Of course, smooth formwork panels.
I also have a concrete vibrator.
(In the past few weeks, I already poured 7 tons of concrete for the garage construction, ring beam, and lintel, but in those cases, the appearance wasn’t important;-))
We have a 1 m (3.3 feet) roof overhang and basically no precipitation there apart from drizzle, but I still plan to create a 1% slope.
From what I’ve read, I should use a good ready-mix concrete, like C25/30 with 0-8 mm (0-0.3 inch) aggregate?
I would place one layer of reinforcement mesh in the middle.
It basically only has to hold its own weight, but it must be smooth.
Some roughness should be preserved to avoid it becoming slippery.
For separation from the facade and front door, I would lay an 8-10 mm (0.3-0.4 inch) thick building protection mat?
That would leave the gap at the door and facade visible.
Can I later fill that with something like Sikaflex Pro 1 concrete gray 1K polyurethane sealant?
For the chamfer, I was thinking of using 45-degree triangular wooden wedges like shown in the picture?
Attached are a photo of our entrance and an image of how I imagine the platform.
Afterwards, I would seal it somehow.
Any tips and suggestions?
I would like to create a concrete platform in front of our front door as exposed concrete.
2 x 0.9 m (3.3 x 3 feet) and about 20 cm (8 inches) high.
It should be just a single low step.
Later, I plan to drive over it with the paving stones.
What exactly should I keep in mind?
Of course, smooth formwork panels.
I also have a concrete vibrator.
(In the past few weeks, I already poured 7 tons of concrete for the garage construction, ring beam, and lintel, but in those cases, the appearance wasn’t important;-))
We have a 1 m (3.3 feet) roof overhang and basically no precipitation there apart from drizzle, but I still plan to create a 1% slope.
From what I’ve read, I should use a good ready-mix concrete, like C25/30 with 0-8 mm (0-0.3 inch) aggregate?
I would place one layer of reinforcement mesh in the middle.
It basically only has to hold its own weight, but it must be smooth.
Some roughness should be preserved to avoid it becoming slippery.
For separation from the facade and front door, I would lay an 8-10 mm (0.3-0.4 inch) thick building protection mat?
That would leave the gap at the door and facade visible.
Can I later fill that with something like Sikaflex Pro 1 concrete gray 1K polyurethane sealant?
For the chamfer, I was thinking of using 45-degree triangular wooden wedges like shown in the picture?
Attached are a photo of our entrance and an image of how I imagine the platform.
Afterwards, I would seal it somehow.
Any tips and suggestions?
D
danielg4028 Feb 2024 21:29So,
I will line it with coated particle boards.
In the end, it will actually be about one metric ton of concrete.
I’m now digging 30cm (12 inches) down all around the outside.
Any tips on how to best achieve a smooth finish by hand? Can you actually over-vibrate the concrete?
Like having too much aggregate at the surface, which might later cause flaking?

I will line it with coated particle boards.
In the end, it will actually be about one metric ton of concrete.
I’m now digging 30cm (12 inches) down all around the outside.
Any tips on how to best achieve a smooth finish by hand? Can you actually over-vibrate the concrete?
Like having too much aggregate at the surface, which might later cause flaking?
D
danielg4028 Feb 2024 22:48Is it worth buying a proper floor trowel, or is a small regular 30cm (12 inch) trowel enough for this area?
What would you roughly estimate regarding when to start troweling with the current weather of about 12°C (54°F)?
Pouring concrete on Saturday around 8-9 a.m., smoothing/troweling approximately 5-6 hours later around 3 p.m.?
Is it advisable to sprinkle cement into the surface while troweling?
What would you roughly estimate regarding when to start troweling with the current weather of about 12°C (54°F)?
Pouring concrete on Saturday around 8-9 a.m., smoothing/troweling approximately 5-6 hours later around 3 p.m.?
Is it advisable to sprinkle cement into the surface while troweling?
D
danielg4029 Feb 2024 11:49So,
I just spoke with a landscaper, and he said...
He has always had good results with freshly directed/consolidated concrete.
The last layer should be poured properly wet and then leveled smoothly together with a screed board and a vibrator.
That’s enough; he has never done any further finishing afterward.
Now I’m wondering what is better.
As I said, I don’t need a perfectly smooth, glossy surface. It should just be even and free of concrete craters and protruding sharp edges.
If I want to smooth it after the curing process later, I probably shouldn’t pour it too wet.
What should I do?
I just spoke with a landscaper, and he said...
He has always had good results with freshly directed/consolidated concrete.
The last layer should be poured properly wet and then leveled smoothly together with a screed board and a vibrator.
That’s enough; he has never done any further finishing afterward.
Now I’m wondering what is better.
As I said, I don’t need a perfectly smooth, glossy surface. It should just be even and free of concrete craters and protruding sharp edges.
If I want to smooth it after the curing process later, I probably shouldn’t pour it too wet.
What should I do?
D
danielg4029 Feb 2024 19:39Nida35a schrieb:
Just do as the landscaper says, then it will be fine.Are you saying that from experience, your own experience?
Could you perhaps find a picture or do you have a picture of what it could ideally look like if I just follow those instructions?
Thanks in advance.