Advice needed pls - 'damp' to wall

[caroline1976]

A BIG help on advice needed!

My house is a 1908 large mid terrace house. I recently started to re-decorate. 2 days after I emulsioned the front living room and after heavy heavy rains, I noticed 'damp' to the dividing wall which seperates the front living room and porch\hallway The 'damp' is not on the hallway side just to the wall in the living room. I have also noticed the porchway laminted floor becoming a little 'bouncey' when you step in one area by the front door-im sure it will give way soon.

I have a broken metal air vent to the front and decided to clear this out in case it was connected (it was very blocked with litter and soil) and also noticed the guttering was cracked roughly over the area where the 'damp' was on the internal wall, so got the gutters repaired. However whenever it rains it gets damp to the touch again, yet doesnt fully dry even when not raining.

The damp proof course was done 12 years ago and I cant see damp anywhere else. It seems very coincidental that it gets worse with rain, so I have weather proofed the brickwork upto 5 bricks high from floor outside.

Photo of internal wall 'damp' showing height of where it looks like water is coming through;

Does anyone have any ideas?

Will my Buildings\Contents insurance cover this do you think??[/img]

 

[JerryM]

The symptoms match the observations.

Air vents are crucial for timber floors. I am that paranoid that I drill out the holes with a masonry drill to make sure max air flow. You need at least 1 air brick every 2m of external wall.

Over spilling water from a gutter splashing up off a hard floor (tarmac, paving etc) on to a wall could bridge the external dpc. If there is debris in the cavity then damp on the inside wall is a certainty (mortar on tie wires is common).

Taking the hall 1st. I would have expected a solid floor. But given “bouncy laminate” observation then it’s possible that it’s wood. The floor could be solid in which case it’s just the laminate that’s bouncy (caused by the passage of wet feet into the house). If it is a wooden floor then the floor joists could have started to rot. If you’re sure it’s a solid floor then forget it until you redo the laminate. If it’s a wood floor then you need to take up the laminate and the floor boards to be sure of what’s happening. Unfortunately if it’s rot then you need to get it sorted sooner rather than later. 2 options: either joiner to replace joists and fit dpc under the joist ends in the walls or damp proofer to treat the joists and put dpc under the ends. Which depends on how much rot (the condition of the joists)

The wall looks like rising damp but it I think it’s more likely bridging of the cavity (most chemical dpc fail within 18 mths mainly due to problems associated with the work not the materials). I suggest leaving it for 2 months (dryout is typ 1 month per inch of brick say 6mths max) to see if there is any improvement. At this point the wall should be dry to the touch. At this time either the gutter is not the problem or salts have moved into the plaster as the water travelled through the bricks from outside. The salts such up water from your room atmosphere and will never dryout (wall may feel dry but damp meter will confirm it to be damp – water > 5%). The rendering should have stopped this from happening but may not have been done properly (re rendering would be required).

If you have got a guarantee then it’s worth following up. The first type is backed by an insurance company and claim success is worth a go or backed by the damp proofer's own company in which case claim success is v.low.

I don’t hold out much for your bldgs/contents insurance but worth a phone call though.