Settlement after 2 years- likely?

[charliegolf]

I am arguing with a conservatory supplier (one with a good name generally) because the floor has dropped some 5-7mm where it abutts the house. Obviously I want it to be their fault, cos there's a 10 year warranty on the workmanship. They say (on a perfunctory viewing) it's settlement so isn't covered. If I have to deal with it, the tiles will all have to rise mucking up the electric ufh, as well as the mess etc.

So, builders, is settlement likely after 2- 2.5 years; or is poor workmanship more likely. Who can prove it one way or the other. Thanks.

CG

 

[^woody^]

Settlement generally occurs within months, sometimes days depending on the soils.

But, settlement will only relate to the main structure, and your floor slab will not settle as it is relatively light and the hardcore subbase is intended to deal with any ground compression.

In any case settlement is even, not just at one location.

 

[charliegolf]

Thanks Woody. The main house has been there for 20 years with no movement. Is your reply hinting at MAYBE the ground wasn't prepared right (my suspicion)?

 

[wessex101]

Assuming it is a ground bearing concrete slab it sounds like the slab has failed, probably due to inadequate compaction of the granular fill/hardcore below the slab or the ground was not prepared properly and they left loose soft soil under the slab. Either way 5-7mm settlement seems excessive and beyond what would be considered acceptable.

My money would be on poor workmanship but they are unlikely to admit to it. You could suggest getting an independent report and if it shows defective work they should reimburse you for the cost of the report on top of the remedial works.

 

[charliegolf]

Thanks Wessex- dunno about the meaning of ground bearing, but it is a glass only conservatory on strips (shoulda mentioned that) with a slab floor on top.

 

[^woody^]

State to them that your understanding is that ground bearing concrete floor slabs of that size and design should not experience settlement.
Ask them for their evidence that this is settlement, along with their reference to the relevant BS/EN standard to support their assertion.

 

[stuart45]

Thanks Wessex- dunno about the meaning of ground bearing,

Means that the weight of the concrete slab is on the ground below it rather than taken by the walls and transferred to the footings.