Jointconstruction

A building survey would be required to validate the integrity of the structural element of the building. also, i would recommend a specialist to investigate any damp and water damage to such a property to determine the extent and causation of water damage.

A 4cm - 4.5cm hieght difference is quite substantial. although this can be packed, i would recommend it is packed only of it can be covered with a suitable trim and any packing is of masonary or structural equivalent. another aspect to consider would be to make sure no water ingress can occur.

Any loose slabs may indicate a failure in the sub-base and/or mortar underside of slab. any sub-base should have an adequate make up of aggregates in correct proportions and quantities to avoid subsidence. a good practice is to paint underside of slabs with a primer to help slab and mortar cohesion. i would investigate and check if these were carried out, as legally there may be an argument to rectify work.