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Damp Proofing

Damp by back door and bottom of stairs in corner

So I have 2 areas of concern:

1) I am experiencing rising mould on my internal walls by the back door and spots of mould are also starting to appear on the corner of the internal wall immediately next to the affected area. I noticed in the corner at times it was very wet on the floor (tiled floor) and immediately thought this was due to my back door, so I recently had the back door re-sealed and re-adjusted. The fitter at the time commented that the area was wet. Initially the wetness appeared worse when raining, however this should not be the case now the area has been re-sealed. I noticed this evening there are what appears to be bubbles of water/condensation on the floor by the back door and it has been a dry day today?? Any ideas what the issue could be?

2. Probably 1 year ago my husband covered an external vent that is situated on the upper level external wall with a metal plate. He did this as this vent was on the other side of the wall to a built in cupboard within one of the bedrooms and a cold draft was coming from this area. Approx 6 months ago it became apparent that the internal walls of the cupboard/purpose-built wardrobe were very wet and the sealant had mould spots as well as the carpet area being wet also. Some of the clothes hanging in the wardrobe had also become mouldy. This was primarily in the one corner of the wardrobe closer to the area where the vent is. We thought the possible cause was the closure of the vent and have since removed the metal plate that had been placed to cover it. My concern is that at the bottom of my stairs in the corner (the internal wall to the air vent wall) there are a few spots of damp that became apparent around the same time of the issue with the wardrobe. I also noticed some strange white markings on the external brickwork at ground level. Since the plate has been removed from the external vent the mould at the bottom of the stairs has not gotten any worse, but still evident and neither have the white markings got any worse.

My question is, was placing a metal plate over the external vent the root cause to these issues? If so, do I need to do any further remedial works?

4 Answers from MyBuilder Damp Proofing Specialists

Best Answer

Hi by what you are explaining it sounds as there is 2 Foult a one is when it rains ( this has to be investigated as that means water ingress is coming as stated by you )
the Room needs ventilation , if you have to much humidity in the house then that helps this as well , in this case a mould removal extractor fan is recommended to be installed , it keeps 80% of heat in the house removes mould and moisture from room self control unit , must say very expensive but works a miracle have had more then 1000 install and all say the same , hope this helps


Answered 29th Jan 2020

External vents in cupboards are there as you guessed to allow air to circulate And not cause moisture to build up within you can buy a vent that opens and closes and if as you say in winter it’s to cold just close the flaps theses can be fixed over existing vent

There’s a good chance there’s now moisture in cavity wall so make sure it’s vented


Answered 29th Jan 2020

Sovereign mark 2 passive vents are good for rooms with high moisture readings.There are easy to install and don’t run on electric,also do not let any cold air into the property.


Answered 30th Jan 2020

Rather then assuming what is causing the issues. Your best bet would be to get a survey carried out. Which will highlight the issues and give you long term solutions. When mould appears 80% of the time is due to poor ventilation.


Answered 3rd Feb 2020

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