jeds said:Unfortunately, that's how these people operate. Wind up the fear factor and then move in with the unnecessary work and extortionate prices.
You were RIGHT! I borrowed a damp meter and discovered by placing it all over the alcove that what I have here are two completely separate problems, something that the damp "specialist" failed to notice.
The meter says that the wall is very wet (off the scale) up to about 6 inches above the skirting, then it is absolutely dry. The centre of the wall, with the black spores, isn't coming from below at all, but from above! There is a thin line of damp readings from the ceiling to the spores, but then beneath the spores the wall reading is completely dry from side to side for about 3 feet, until just 6 inches above the skirting.
Went up to the bedroom above, and to the other bedroom above THAT bedroom, and there is the same thing: an invisible vertical line, about 3 inches wide, showing high wetness, the rest of the alcove bone dry. This vertical line goes from the ceiling of the 2nd floor room right down in a straight line to the alcove in the lounge, where the spores are.
My conclusion is that I have (1) a roof leak and (2) damp coming from beneath the floorboards.
The black spores are unconnected to the floor damp, but have appeared where the roof leak water has decided to "pool".
I must confess, I feel relieved at this discovery. Yes it means I need a roofer, but that is better than ripping up an entire newly laid laminate floor!
you do need to remove that bottom panel and skirting. The side pieces will be fine and, if appropriate, a new bottom panel could be re fitted without too much disruption. But, unfortunately, it does need to come out. I would get that done first and then report back with what you find.
Thanks Jeds.
Did that yesterday. Lifting the base panel took ages as the screws had been countersunk extremely deeply and the gap all around packed with ancient filler. Needed an hour's work with a Stanley knife! But I digress...
The rot was not as bad as I thought it would be. Only half of one floorboard was rotten enough to be pulled out by hand, the rest of that one and all the others are sound. Looking at the joists underneath, the ends are rotten, but not to the point of collapse. I don't think they need replacing.
I am convinced that the problem has arisen because the 4 air bricks outside the room right at that corner are far too low ~ they are level with the patio! We had a LOT of torrential rain a few months ago, and the patio flooded over and over. So much water must have literally poured through the air bricks and into the space beneath the floor boards.
Today I am going to examine and decide how to get more air to circulate under that panel and into that hole in the floor.
I shall also at some point cut out all the crumbling plaster and the plaster with the black spores.
I'm not going to get the whole alcove replastered, just a patch where I have cut out.
I'm not paying £1,800 to some blooming shyster to rip me off! But I will be paying a roofer to repair the roof and a builder to change the outside so that the air bricks don't let in any more water!
I hope I am making the right and wise choice!
I'm adding some pics. Those aren't my hairy arms in the photo, by the way! A friend kindly offered to help me to uncover the problem!
LHL