ᐅ Should concrete paving slabs (5 cm thick) be compacted with a plate vibrator after installation?

Hello everyone,

I have created a foundation using concrete paving slabs (50cm x 50cm x 5cm (20in x 20in x 2in)) laid on a bed of gravel. My question is whether I should compact the slabs any further after grouting, or if this is unnecessary and might even cause the slabs to crack given their size and material.

Thank you

Regards,
Jörg

Hello Jörg,

What kind of load will the “foundation” have to bear? And how compact is the gravel bed?

I’m planning something similar for the upcoming season.
I want to use the slabs as an alternative to a poured concrete slab.
I will be placing a hot tub weighing about 1 ton (1,000 kilograms) on it. I would definitely compact the base if it will be heavily loaded.
This year, I laid paving slabs in the yard as a regular walkway, using slabs measuring 30 x 30 x 4 cm (12 x 12 x 1.5 inches). I did not compact the base for that. There, I removed the old paving and raised the already compacted gravel bed by 3 cm (1 inch).

Best regards

JoergJ schrieb:

Hello everyone,

I have created a foundation using concrete paving slabs (50 x 50 x 5 cm (20 x 20 x 2 inches)) laid on a gravel bed. My question is whether I should compact the slabs again after grouting, or if this is unnecessary and the slabs might even break due to their size and material.

Thanks

Best regards
Jörg

No, they will break.

I also used these panels for my garden house. Lay them down, align with a rubber mallet/level, and you’re done. They are so heavy that they stay perfectly in place on their own.