We moved in to our new home last year, and in January has a dishwasher (our first!!) plumbed in to the kitchen. The dishwasher is positioned two cupboards along from the sink, if that makes sense, with a long hose connecting it to the waste pipe under the sink. A couple of months ago I noticed that the plinth under the under sink cupboard, which is made of (dated horrible) pine, was a darker colour, an on closer inspection was damp. The lino (dated horrible lino) had also puckered where it goes under the unit.
I called the plumber back to look, and he unscrewed the boards at the back of the cupboards, and it was like a lake back there. The concrete floor was awash. He tightened the connection to the dishwasher and told me to monitor it, to see if the water had dried up.
That I have been doing, and can report that the concrete underneath the kitchen sink cupboard is now dry. Our kitchen adjoins our conservatory along the wall that this kitchen sink is on. In the corner, where the conservatory joins the main house, I spotted damp when I was clearing the room to be re-carpeted last week. I pulled up the corner of the carpet, which was sodden, and the concrete under there was wet. The wooden skirting has rotted at the bottom where it meets the floor, and there is a watermark about 6 inches or so up the wall. I delayed the carpet fitter while we get to the bottom of the damp.
So (and thank you for bearing with me if you are still persevering!!), not putting two and two together, I called a builder out who thought that perhaps a down-pipe from the main house, that runs down the wall and into the conservatory (behind a stud wall) into the drain below, was leaking. He quoted about £3k, as there would need to be scaffolding to get over the conservatory, then guttering etc would need removing/altering etc. Stupidly I hadn't thought about the dishwasher issue when I spoke to the builder, I thought that problem was isolated to the kitchen, but now when I think about how much water there was, perhaps it is not out of the question that it seeped through into the adjoining room, and pooled on the concrete floor, eventually making its way up the wall.
I've called the plumber again, as I suppose I need to establish what has caused the damp, the leaking dishwasher connection, or a possible leak with the down-pipe. The builder had no evidence that it was a leaking down-pipe, he just thought it must be to explain the presence of the damp in that location.
My question is, if the damp was caused by the plumber plumbing in the dishwasher incorrectly, would he be liable for any of the damage that has been caused (to the conservatory wall, skirting, floor, carpet)? How would you proceed in this case? I suppose he will argue that I can't prove it was due to the dishwasher?
Further info: when he plumbed in the dishwasher, he plumbed our washing machine in the utility room, and within days there was a pool of water coming out from under the machine. I called him back and he said that the connection joint (don't know the technical name) was faulty, this had never happened before, but he replaced it. We naively didn't think to have the dishwasher connection checked back then, it didn't appear to be leaking, and we assumed the fault was a one-off (now feel stupid that I didn't insist he change both). The plumber seems a decent chap, well recommended by friends locally, and he has been very helpful about coming back every time I have contacted him, so I want to handle this correctly - but not be a complete doormat if he has done something wrong and caused damage. Any thoughts greatly appreciated. Sorry this ended up being so long!!