This might take a while so sorry.....I noticed a damp patch in my conservatory in the corner where the dwarf wall meets the original house (a new build from 2003).....anyhow, took up the laminate to discover the entire width of conservatory insulated boarding was covered in black mould....fast forward, after lots of complaints etc to the well known national company that built it they came out and agreed that I was right in the fact that the existing airbricks in the house should not have been comprimised (there were no airbricks in the conservatory )..We are now in April and they came out, channeled through the concrete floor and put in two pipes and installed airbricks to the outside, then they relaid the insulated boards. At the time I questioned that surely if they hadn't sealed off around the pipes any air coming through the original airbricks would cause the same problem.....they assured me the quick painting on of bitumen would be fine and went away leaving the dpc membrane still visible under the door.......Next day damp patches appear on the floor, where the original airbricks were.......two weeks later manager comes out again and says doesnt know what the problem is. I suggest that the dpc should be either lapped into the orignal house or sealed against the wall to prevent the damp. (the conservatory is North facing and quite damp at the sides........He rings me tonight to say its drains.....I argue this as a friend who is a surveyor said no, and also we have had torrential rain the last few days and this didnt make the problem worse........the next thing he says is its from the cavity. but the walls are dry..........Am I right in thinking if a couple of inches of plaster board were removed from the wall (This was put on to the original render of the house) and the insulated boards not rammed up against the wall, and if the dpc that is showing was sealed to the original wall this would solve the problem?.....This is now making me ill......The company says they will not pay if I get a chartered surveyor in to give a written report. I have spoken to builders, researched and looked into this myself.......I'm sorry for rambling but battling with companies who call you liars and threaten you is really upsetting me.........Thank you for reading this if you got this far.[/img]
Its very hard to comment on your exact problem without pictures can you upload them,And I will try to give you some specific answers.
It could be they have hit a waterpipe or a drain,or the damp proof membrane has not been installed properly or has holes in it.
It would be better to have knock out your existing house airbricks installed a 100mm plastic pipe from your new airbricks to just inside your house,concreted in place and paint the entire floor with bitumin paint then lay your boards
Thank you for your reply, I will try to see how I upload pictures.....They did knock holes through the original plastic airbricks and pushed the pipe through, they concreted over the top of the pipes, but they didn't appear to seal off the area left around the pipe.......the damp appears first thing in the morning and has disappeared as soon as the room warms up........this damp is appearing where the original air brick was and a draught can be felt if you put your hand under the plasterboard....The damp come up between the original house brickwork and the dpc, it doesnt come through to the concrete base of the conservatory, that occurs as the insulation boards touch it and it 'seeps'.....I'm sorry if I dont make myself very clear. In addition, the house outside originally has 4 layers of bricks with the airbrick in the top layer, then there is render to the top of the house. There is one drain in the corner of the property for the guttering and this runs back on itself to the front of the house. I would of thought if it was a cracked drain the water would be visible all the time......Thanks
from the pictures It looks like the damp could be penitrating the render and running down the wall behind the drylining and showing on the floor.
Try hosing the render above the conservatory heavily and see if any water appears on the floor,also check the flashing on the conservatory roof .
welsh brickie wrote:from the pictures It looks like the damp could be penitrating the render and running down the wall behind the drylining and showing on the floor. Try hosing the render above the conservatory heavily and see if any water appears on the floor,also check the flashing on the conservatory roof .
No, if you put your finders under the gap the rendered wall is bone dry. When the floor was taken back down to the concrete pad, the water/condensation/damp rose upward. It definitely looks to come up the wall and the dpc touches the insulation board so it gets wet......I experimented and suspended the dpc away from the board in a couple of places and it stayed dry, hence me thinking if the dpc was sealed to the existing brickwork and the insulation boards not rammed up to it, with a half inch gap it would solve the problem........