Heating engineers or builders - advice required

[Vultch]

To the forum that knows all,

To cut a long story short I rented out my place whilst I am working away.
I lived in the place for over 10 yrs with no issues...

My tenant complained about two of the rooms being cold so I arranged to put in more powerful hot water radiators and a new gas boiler. Problem solved except within 2 weeks of this these two rooms have mould forming on the walls.

It can be wiped off easily with a cloth also my neighbour called round and said there is running condensation visible on the double glazing when viewed from outside, just like a sauna.

There is no rising damp the construction is fairly modern and well maintained.
I have no idea what is causing this and I will be returning to see the problem.
Any ideas out there.

thanks

[StevenN]

I don't think you need much knowledge to see the property has inadequate ventilation.
you could check to see if you have some water ingress due to faulty guttering or drains but my guess is that if you had any air vents they have become blocked.

If you need air vents Google Black Hole vents as these will provide clean air without too much heat loss.

[Vultch]

Thanks Steven

There is no water ingress, the rooms in question have air bricks. I suspect the tenant may have blocked these up.

[Bogus]

Thanks Steven

There is no water ingress, the rooms in question have air bricks. I suspect the tenant may have blocked these up.

The tenant is probably drying laundry in the house.

[slobodan]

What Alex said, Plus the hotter the temp, the more moisture it holds, maybe the rooms are too warm.

[jmcbohola]

The black hole air vent would be the best option but you would need a kango drill and a 4ins core bit will take about an hour to do properly and is noisy and dusty you could try a trickle vent which goes in the window sash and is much easier to put in

[Vultch]

Thanks for the replies guys..

these two rooms are bedrooms, the main bedroom and biggest has a decent airbrick type vent installed when the house was built.
The All rooms double glazed have opening windows, I suspect the place has not seen fresh air in some time.

I now worried about long term damage to the property, it has suspended wooden floors excessive damp cant be good for the floors

[slobodan]

I rented out when I moved out here, after a year of nothing but hassle we sold it.
Maybe not a good move financially, but it saved a lot of worrying.

[Vultch]

I agree with you slobodan, its been nothing but hassle and pain. I lived in the place for yrs with no problems and I spent a fortune doing it up.
I may decide to sell up.

[Shadyadie]

Damp like you describe is common place with rented properties, usually caused by not enough warmth and too little ventilation.

Main causes

Drying washing,
Bathroom vent turned off (this is what my tenant does)
pets, a dog can breathe out 2 litres plus of moisture a day.
cooking and not using extractor fan


Once it stains, it is a re-decorate job.

You can't force your tenant to ventilate the house especially during winter.

[Vultch]

Oh good tenant has a large dog etc, I love mutts but opening a window every now and then is a good idea.
The place is pumping out fantastic amounts of heat I have politely asked her to vent the house every now and then and uncover the air bricks if she has blocked them.

[meooo]

We have similar problems with condensation this time of year, so we run a de-humidifier 24/7 and move it to different rooms as required, its amazing how much water it collects, needs to be emptied daily .... about 5 litre tank.
The more its used, the drier the air and the warmer the house feels.