The Brew Cabin

I have had a patio on the back of my house block paved and I am sure the contractors didnot compact the sub base or the sand screed layer.However they did go over the entire surface of the block paving with a whacker after they had laid them. What is the result of such a situation and is there some way of determining if the sub base was compacted now the paviours have been laid and whacker plated.

If the sub-base was not compacted prior to laying the blocks, then you will experience settlement of the pavement over the next few weeks. This could be quite significant, depending on the thickness of the sub-base, the type of material used and the effect, if any, of the final consolidation.

Not compacting the bedding layer prior to laying the blocks is less of a concern - one of the acceptable laying methods allows for an uncompacted bedding layer, but the vast majority of contractors shun this method as it gives highly unpredictable results.

In theory, you could take up a section of paving to determine the degree of compaction achieved with the sub-base. This would normally only be doine if there was some good reason to suggest the sub-base was incorrectly constructed. It would be more usual to wait for 2-3 weeks to see if any settlement does appear. Believe me: if the sub-base was not consolidated, the paving will sink more or less immediately, especially in the wet weather we've been having for the last few weeks.