Damp advice.

[jeff oakley]

Hi All,

 know we have some knowledgeable people on here from all walks of life so hoping someone might throw some advice my way. 

 

 

We own a property that is leased to the council and there has been black mould on the wall by the window. It is about 30 years old the house and the cause of this mould we believe is the tenant not ventilating the room. Only happens in this room.

 

The council expert is saying it needs a breathable membrane on the roof which makes no sense to me as there are air vents all around the suffits so the roof space should be well ventilated as it is.

 

I did suggest fitting window vents but this is being said as not curing the problem. None of the neighbours homes have had work done so any suggestions?

 

Also if it did need this membrane, I am told they do just a metre section at the bottom, how much should this cost as a guide?

 

Any advice appreciated.

[wizzer]

Hi Jeff 

Mould around the window could  point towards the sealent around the frame especially if it gets a lot of weather. 

As for the roof can't understand why you would need breathable membrane if the roof is vented from  the soffit/ eaves ,if that's not good enough couldn't you just put the odd vented slate or tile on instead of striping and felting..

Tony 

[Geoffrey Carter (Buttercup)]

It would be interesting to see how the breathable membrane would work. 

 

Is there any condensation on the windows.

 

I would treat the mould with spray domestic bleach for 5 minutes and then wash it of. The spray bleach will kill the spores.

 

For the cost of the trickle vents, I would try them first.

 

How many people are in the room and do they boil a kettle in there perhaps.

[Andrew O Byrne White - Ireland AO]

I've always used a dehumidifier, especially if drying clothing indoors. That can make a pretty big difference (and the drier air is easier and cheaper to heat). 

[Terry Everall]

sounds to me like its mould growth due to condensation. The roof option is no good IMHO and you need more ventilation in the room to help moist air escape

[jeff oakley]

Thanks for the replies so far. We have no knowledge of what they are doing in the house as it is the council who manage, or ot may appear mismanage the house. 

 

It is their contractor who is saying it needs this membrane to sort it out but I suspect he is just looking for a soft income stream. Structurally there is no know problem of seals or such like.

 

I thought if there was roof ventilation it was more likely to be the actions of the tenants rather than anything else. 

 

As for condensation on the windows Geoff I do not know but they are sealed double glazed units. I suspect that the tenants are simply not ventilating the house at all. Killing the spores and it is just around the windows I am told is easy to do but they want to stop it returning.

 

I just wanted some opinions to go back with.

 

Thanks for the advcie

[Kit Car Electronics]

I don't know if a 30 year old house would have thermal cavity closers ( @Mark (smokey mow) might) but if there's a cold bridge around the windows and no ventilation then mould will tend to grow. I fitted trickle vents to a bedroom upvc window that made a huge difference to winter condensation on the walls around the window. Also check the outside wall for dampness from blocked/ leaking gutters. 

[Mark (smokey mow)]

Quick answers as i don't have much time but will try to reply later.

 

a breather membrane to the roof wont fix a damp problem in the room, they're there for the benifit of the roof.  

 

A 1m strip of breather membrane is a complete waste of time and effort.for the above reason.  Breather membranes also only work when on a fully sealed roof with no eaves ventilation,  to produce the same amount of ventilation as you have at the soffit it would require the whole roof to be done.

 

Trickle vents would certainly help a lot but the tennant needs to learn to use them.

 

a 30year old house wont have insulated cavity closers, the blockwork will be returned at the reveals and there should be a damcor or similar vertical dpc.

 

dehumidifiers can sometimes create more problems as it encourages the moisture to the inside of the wall rather than allowing it to migrate through the building fabric to the outside.

 

most likely its the tennants drying clothes in the room.

 

 

Are the windows the orignal ones or have they been replaced in the last 30years, if so when?

what is the wall construction, is it brick outer or rendered? If rendered are there any noticable cracks?

are the gutters clear of leaves or other blockages?

can you post a streetview picture of the outside of the house, it may give some clues.

 

[Mole]

I had the same problem in a flat I bought in 88.(yes another story!) Fine while me and the girlfriend lived there...doing normal things that a young couple does.. it was ground floor with top hinged windows... also only had storage heaters...I opened windows when ever possible..but not easy on ground floor. Bought a dehumidifier and had no issues..

Moved away and rented out..had so many issues with mould and Tennant's. Even put full width trickle vent in..but most Tennant's never opened a window and used to leave washing to dry in rooms etc..

In the end I sold the property as fed up with Tennant's and estate agents..

Problem was purely lack of heat and circulation and occupants not opening the windows!!

Breathable membrane is not the solution..

[Snappy]

Mole I have had the exact same issues with a property I rent out, some tenants have a problem and some don't thus it isn't the property.

 

As a preventative measure which worked for us was simply to disinfect and thoroughly clean the area then multiple coats of anti mould and stain blocker and repaint. That works for a couple of years then redo!

[jeff oakley]

The house in question is the one with the green Rover outside.

 

Roof looks good no loose tiles gutter clean.

 

Not sure on the age of the windows but generally in good condition, well last time we were there. 

 

I have a meeting with them next week to discuss this but the more we look at it it is tenant action that is the cause.

 

 

[litcoat]

As Mark has said it is probably cold bridging, , what you need is a barrier to stop the warm internal air coming into contact with the external window reveal.. depending on what depth you have on the window frame you can line the reveals with an insulated plaster board and plaster them in. This creates the barrier and will stop the problem. It is also easier than taking the window out and getting an insulated dpc in there.

[SXRORY]

Noticed it in our bedroom some spots forming around the window area. We thought we vented quite a bit, but not enough. looked it up Decent ventilation everyday at least 15minutes. 

its Never come back

 

[BigSkyBrad]

Reduce the number of families living in it from three to one, and dismantle the meth lab.