Mould on Felt

[sarah123]

Hi,

A few months ago I noticed some condensation on the roof when I went into the loft. At the time I thought nothing of it. It was very cold outside and the condensation was on the north of the house. I assumed it was just due to the cold air on the outside and the warmer air inside.

I went into the loft last week and noticed some mould on the inside, where the condensation was. See image below:

Some of the items int he loft have also got mould on them too.

Does anyone know what needs to be done to solve this?

Many Thanks
S

 

[pinenot]

Condensation on the roof! I'll assume you mean condensation on the underside of the roofing felt, which means there is moist air in the loft space, otherwise there could be no condensation, this needs to be vented. So! is the loft insulated and if so has there bean venting gaps left at each side (the eaves) to allow a trough flow of air? do you have ridge vent or tile vents in the roof structure?? etc. ...pinenot

 

[sarah123]

Hi,

Thanks for the reply.

Yes, it's on the underside. The loft is insulated, but I'm not sure if there are venting gaps by the eaves. I assume there are as this problem has only just occurred - the house was built in 2003. Not sure if there are any ridge vent or tile vents in the roof.

I only noticed it was like this last week as I was inspecting the property - it's being rented out. I lived in the house for 5 years until a year ago and never had this issue.

I notice on the sticky at the top there is mention of a poorly sealed loft hatch. A new hatch was installed 6 months ago as a previous tenant smashed it. The new hatch is a bit of a tight fit, and doesn't close easily. Could this be causing the problem? Seems like too much of an easy fix to me.

Many Thanks
Sarah

 

[pinenot]

Still if the previous tenets were high moisture producers, hot air rising would carry this into a not to well sealed loft area, and physics then takes over from there.
If you were in the loft on a windy day, light a candle and watch the flame, that will tell you if there's cross ventilation...pinenot

 

[sarah123]

Still if the previous tenets were high moisture producers, hot air rising would carry this into a not to well sealed loft area, and physics then takes over from there.
If you were in the loft on a windy day, light a candle and watch the flame, that will tell you if there's cross ventilation...pinenot

Thanks for the advice. Will try that next time I'm in there.

Does anything need to be done, other than ensure proper ventilation etc? I'm concerned the felt might need replacing.

Many Thanks
Sarah

 

[pinenot]

Nothing that I'm aware of, proper venting will do it...pinenot

 

[sarah123]

Thanks for the reply pinenot.

The property is now being 'managed' by a letting agent. They rung me today and informed me their property maintenance company said it will be a big job to sort out. Apparently they thing all the felt will need replacing.

I mentioned the ventilation to the agents, but they clearly don't think that's the issue.

Slightly worried we're going to get an unnecessary bill for work that doesn't need doing. The tenants still have things in the loft, which are covered in mold. I've told the agents to ask the tenants to remove any moldy items and to ensure the loft hatch is closed properly.

Need to find a respectable tradesman to check the vents etc.

 

[pinenot]

Not all letting agents will be the same, but my daughter left her house in the hands of one of these agency's, they told her that a leak had developed and her flat roof extension needed to be replaced. They had brought in an expert, and said expert noted that the front hallway, at the door, was wet. Although the hallway ceiling showed no water marks etc. he inspected the flat roof above the hallway and declared this required replacement and added the rest of the roof was needing replacement as well. I had a look myself (experience - built up felt roofer - joiner, construction management) turned out the letterbox in the door had a week spring, and during wind and rain the floor got wet often (the tenants failed to mention this) this one particular time the wind and rain being exceptional, the floor got even wetter. Anyway to cut a long story short, the letting agent offered to have the works done by one of their retained companies - £5,750, I had the letterbox replaced £38 job done. The moral here is don't put your trust in anything a letting agency tells you unless it's about letting...pinenot

 

[tony1851]

Do you have any downlights in the bathroom which could be letting moist air into the loft? Is there adequate mechanical ventilation of the bathroom? Do tenants dry their washing on radiators? etc etc.
Thee are the sorts of questions you should be thinking about before you let tradesmen start ripping your roof apart.

 

[JohnD]

//www.diynot.com/forums/viewtopic.php?t=160032

I expect the tenants have been draping their wet washing over radiators.

 

[sarah123]

Not all letting agents will be the same, but my daughter left her house in the hands of one of these agency's, they told her that a leak had developed and her flat roof extension needed to be replaced. They had brought in an expert, and said expert noted that the front hallway, at the door, was wet. Although the hallway ceiling showed no water marks etc. he inspected the flat roof above the hallway and declared this required replacement and added the rest of the roof was needing replacement as well. I had a look myself (experience - built up felt roofer - joiner, construction management) turned out the letterbox in the door had a week spring, and during wind and rain the floor got wet often (the tenants failed to mention this) this one particular time the wind and rain being exceptional, the floor got even wetter. Anyway to cut a long story short, the letting agent offered to have the works done by one of their retained companies - £5,750, I had the letterbox replaced £38 job done. The moral here is don't put your trust in anything a letting agency tells you unless it's about letting...pinenot

Wow, that's terrible. Imagine how many other landlords will have been using that 'tradesman'. At least your daughter was able to use her dads knowledge, which saved her a few pounds.

Do you have any downlights in the bathroom which could be letting moist air into the loft? Is there adequate mechanical ventilation of the bathroom? Do tenants dry their washing on radiators? etc etc.
Thee are the sorts of questions you should be thinking about before you let tradesmen start ripping your roof apart.

There are 5 downlighters in one the bathroom, and 3 in another shower room. How would the downlighters let moist air into the loft? Would it be becuase they aren't sealed?

Both rooms have extractor fans, and were working the last time I checked. Having said that, they switch on when the lights on, so in the summer they might not get used. I guess it's also possible they have got dirty and/or not as efficient as they were.

Not sure if the tenants put washing over radiators. I could tell the agent to ask them.... whether they answer honestly is another issue.

The loft is insulated and boarded, so if there was moister rising into the loft, wouldn't the insulation prevent it from rising and causing this issue? Sorry, thats probably a stupid question to those in the know,

//www.diynot.com/forums/viewtopic.php?t=160032

I expect the tenants have been draping their wet washing over radiators.

Thanks John. I noticed that thread just after posing this one.


I am going to email the agent a list of potential issues (again).


Thanks to you all for your replies. We use an agent as it does help most of the time, but they don't help with things like this. I wish I could get the keys back and just go in myself.

Sarah

 

[sarah123]

Just got another email from the agent.

Apparently they had another contractor to have a look at the problem. He said that all the ventilation shafts have been covered up by wooden floor boards.

The cost of clearing all vents and treating the loft with anti mould killer will be £180.

Not sure what 'anti mould killer' is though.

 

[tony1851]

He said that all the ventilation shafts have been covered up by wooden floor boards.

What does that mean?

 

[sarah123]

He said that all the ventilation shafts have been covered up by wooden floor boards.

What does that mean?

I don't know, that's just what the agent told me he said.

The loft had floor boards over the joists (if that's the correct terminology) when we moved in, so we could store things in the loft. We lived there for a number of years before renting it out and never had this problem.

I 'assume' someone has boarded over the ventilation gap in the eaves. I do think something else might also be causing this, as I cant imagine a tenant putting boards in the eaves, blocking the ventilation.

Do you think I need clarification of this before agreeing to the work?

 

[pinenot]

I think you need to identify the validity and or virility of this mould and would suggest you invest it one of these - http://www.mouldcheck.co.uk/epages/...Path=/Shops/es142051/Categories/Mould_Testing - I would say the mould on surface test kit and a talk to these suppliers would be a good move...pinenot