I've got an issue whereby water is getting into my house whenever there is moderate-heavy rain. This is a new build from 2015 (maybe that's not so new now...)
I suspect it is coming in via the front door, but there is no visual evidence of water ingress anywhere - however, walking around there is a very audible sloshing under the floors. But the flooring itself (including carpets) is bone dry.
I've tried calling a few damp specialists but without visual evidence of water they can't do much. The original builder (big national company) doesn't want to hear it as it's out of warranty. NAHB won't look into it without visual water damage - so I'm on my own for now!
The construction of the flooring is (bottom up):
I've tried to make a schematic below of where the water can be heard in the house. I think it enters at the front and then is just pooling at low points. The heavier the rain, the further into the house the sloshing can be heard.
I've investigated for cracks, poor/broken sealant, any way the water can get in but can't find any. I removed the blocks at the threshold and concrete is still intact with no obvious damage or cracks.
If I move aside some of the gravel at the side, there is some plastic membrane you can just about see.
The garage (white door on left) which is at a lower level than the front door is completely bone dry, even during heavy rain. There is no pooling of water on the lockblock either. Everything is very level (build to wheelchair standards).