Humidity in the loft

[stevepbuk]

Hi,

I have a quick question regarding humidity. The humidity in my loft currently ranges from 70 - 80% on a daily basis. The humidity outside is higher at around 92%. Is high humidity in the loft going to cause problems. The humidity around the house is in the region of 50-60% so I can only think that it is the air coming from outside that is increasing it in the loft. I have tried a dehumidifier in the loft but the day after I turn it off it has creeped up again, so effectively I am wasting my time. I have been up the loft several times and it all appears dry.

Am I panicking over nothing.

Thanks in advance.

Steve

 

[freddiemercurystwin]

Is this a normal loft or a converted loft?

 

[stevepbuk]

Hi,

Its a normal loft. Its got a small section of boarding.

Thanks

Steve

 

[freddiemercurystwin]

Is the loft well ventilated at the eaves?

Where do the extractor fans in the house ventilate?

 

[stevepbuk]

The loft appears to be well ventilated. It has gaps at the eaves and two vents in the roof itself ( I cant remember there name ). As for the extractor fans, they are all ventilated outside. When Im up the loft on a breezy day you can feel the breeze coming through the loft.

Thanks

Steve

 

[freddiemercurystwin]

Well there is either excessive moisture getting into the loft from the house ie via the bathroom lights maybe (spotlights?) or from another source.

Or not enough ventilation. If ventilation is adequate the difference in conditions between inside the loft and the outside will be marginal.

Or a combination of the two.

Is there insulation at ceiling level?

 

[stevepbuk]

Hi,

Thanks for your reply. The humidity outside is very similar to the humidity in the loft. Outside appears to be roughly 10% more, however the weather station is near the bottom of the garden and there is a small stream near by ( Im not sure if this would effect it ).

The humidity in the house ( I have tried various rooms ) doesnt seem to ever exceed 60%.

There is insulation above the ceiling in the loft. Could this be making things worse?

Thanks

Steve

 

[freddiemercurystwin]

The insulation should halt the warm air rising into the loft and if anything should reduce humidity in the loft. If you still have high humidity in the loft you need to ventilate more although there's not much you can do if the humidity outside is that high too other than using a dehumidifier.

Are you sure your weather station is accurate? Is this a peak reading of average or what?

 

[officialsimon]

What are the implicatioins for ventilation from the eaves if you intend to to put a stud partitition a few feet in from the eaves where the floor purlins are? That's going to close the main loft space off at above floorboard level to the eaves innit?

Is eaves ventilation for that loft space or is it for the below floorboards area, ie where the insulation is, or both?

Presumably roof vents (I have two) are adequate for the actual loft space if you close the eaves off to it?

I do of course have a cold water tank in the loftspace (it's slung on supporting timbers between the two upper purlins against one of the party walls), does that need to have a lid on it? 'Cause currently it don't.

And what are the implications for trapping pipework to that tank under new floorboarding?

 

[mointainwalker]

@stevepbuk

Am I panicking over nothing

I think so, yes.

If you have just got a GBP 30-40 weather station, it's not necessarily going to be very accurate.

Unless you have rare books to protect or you can see evidence of condensation in the house, I certainly wouldn't get worked up over different readings in different areas.

PS Officialsimon.

It's not very polite just to jump in on another person's thread, because you can't reasonably have different answers and opinions being directed to different people - too confusing.