Another damp question!!

mjs67

Following on from other damp questions posted I am totally confused as to what steps to take first in removing damp problems.

Always had condensation issues in the house but in last 12 months mould is appearing on one bedroon ceiling and damp patch on another bedroom wall.
Main issue is one wall near front door where damp is starting to remove plasterwork.
Had 2 damp companies look at problem and quote over £1200 to replace damp course and replaster wall without even looking at where the damp is coming from.
Contacted company that installed cavity wall insulation for previous owners and under CIGA they took a look and confirmed that although there isnt an issue with the insulation it is soaking.
Tried all usual suspects of gutters and drainpipes etc, found a gap in the felt on the porch roof (has flat roof and is very close to damp wall) this has now been sealed.
Question - will a dehumidifier help to dry out the insulation as until it is dry I cant tell if the roof gap was the issue?
Also been mentioned that the rendering on the house is cracking and ideally needs replacing incase that is the cause. Is this likely to cause so much damp?
Getting a wide range of suggestions to sort the problem but most seem to be very big, expensive jobs and obviously I would like like to try smaller solutions first if anyone has any suggestions.

thank you

tony6403

A dehumidifier will certainly take out internal moisture and may stop your ceiling and bedroom problem : I doubt that it will dry your insulation.
It sounds like you have gone through the common causes of damp but have you thoroughly checked the sealant around your door frame for any gaps or deterioration?
What type of cavity wall insulation do you have?

TamA

The inner and outer leafs of the wall are seperate. You mention that the render is cracked externally as well as their being moisture internally. If you think the two could be related then it is not a problem with ventilation in your house. What is above the affected area? I can't see that much moisture from outside passing the cavity and then into your house ro cause mould. The felt roof you have could be harbouring a lot of hidden water underneath that has seeped through over time. It might be an idea to replace this depending on the cost.

What I would do is:

-Open all windows to allow it to dry out as much as possible(I know it is cold this time of year!) If you have a dehumidifier, then brilliant.
-Paint over mould
-When showering or cooking heavily or even drying clothes, try and allow as much ventilation as possible.
-Any internal airbricks or vents - make sure they are not blocked.
-Any external air bricks make sure they are above ground (ideally 150mm). Remove vegitation or whatever is covering them. Poke the holes through to make sure they are not blocked.
- examine external render and touch up if you can. Underneath this should be brick or block assuming your house is not a timber frame so it shouldnt really matter about it's condition.

Render is mostly aesthetic unless you live somewhere extreme.


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