Never ending..Augean stables..This time Loft condensation-

3 months ago

Hi Everyone,

Hope all are well, have done with your Xmas shopping and staying warm.

For me, 2022 has been a bright year, with several challenges and changes, a huge increase in workload but same time a positive experience on the whole.

I thought I had sorted the loft, after throwing away the previous rotten and itchy insulation and replacing it with wool. Still had a few things left to do, so went up the loft this weekend, despite having a cold and fever.

Sadly found evidence of condensation, with water droplets all across the felt and even the wood being partly wet... bummer. I thought I had sorted this attic so was, as-usual upset. Every week a new challenge, and the faster I sort one out another one crops out..like the Augean stable, a never-ending chore.

After using google, youtube and amazon came across some theories

1) Due to the cold snap? Snow on the tiles, with warm air coming up --condensation?

2) Possibly vigorous DIY, pushing the new insulation, blocking some of the eaves?

Can't think of anything else, maybe old felt?


Start with a dehumidifier.

Keep the loft hatch open for a couple of days

use a heater in the loft? is it safe? could help to dry things up a bit

Online they recommend lap vents? Seem easy to fit and has positive reviews, any experiences?

Please do advise



Comments (8)

  • Jonathan
    3 months ago

    How do you get up your loft so often? I lived in my last house for 5 years and never once went in the loft!!

    Most likely it’s a temporary problem related to the cold weather. I would rule out a couple of things….. is heat getting up your loft? Is your hatch insulated? Do you leave the hatch open? Also is the bathroom extractor actually extracting to the outside or is it venting into the loft?
    And lastly there should be some ventilation grills at the side of the roof pitch- are they blocked?

    HU-768402840 thanked Jonathan
  • Sonia
    3 months ago

    I haven’t been up in my loft for about 20 years so god knows what’s up there...........😱

    HU-768402840 thanked Sonia
  • HU-768402840
    Original Author
    3 months ago

    I use a ladder and get up.

    actually quite like it!! will look into all of those


  • Ruth House
    3 months ago

    Hi, we have this exact problem after months of hard work insulating and boarding the loft, it is soul destroying so I understand your upset. We too have come to the conclusion that maybe we did push the insulation too far into the eaves. Our research said to leave a few cm but in hindsight we should have been more generous. Also the cold weather was quite sudden. But we believe the main culprit was poorly fitted spotlights in the bathroom along with a very old probably inefficient extractor fan so we think that is where warm moist air is getting from house into loft. We've improved the lighting and are showering with window wide open and dehumidifier running for half an hour after. When we redo the bathroom we're having extractor on side wall not through loft and also not having spot lights which should help. We will also buy a litter picker to pull our the last strip of insulation from the far reach of the eaves to improve ventilation. Have you found any other solutions which have improved things for you?

    HU-768402840 thanked Ruth House
  • Lisa Dalheimer
    3 months ago

    Big problem for many it seems right now. Ours is dripping and the insulation wet, we only popped up to get Xmas presents down. Internet suggests it’s the cold snap, we’ve never seen it before so aren’t going to panic. We’ve gone away for a few days so left the hatch open and hope it will dry. My parents also have the same issue.

    HU-768402840 thanked Lisa Dalheimer
  • HU-768402840
    Original Author
    3 months ago

    Thanks to everyone who replied

    Just an update

    So over the weekend, went up to the attic, armed with several tools. One was a pocket temp and humidity gauge, which showed an initial reading of 2 C and a humidity of 90%

    I also bought an industrial strength dehumidifier, Powerdri 18 L, and popped it up on Saturday morning. It claimed to suck up to 18 L of water per day. Came back in the afternoon, just had around 100 mls in the water tank, a damp squib. Humidity still remained at around 75 and temp the same.

    So got my portable heater, the standard one you use in the room and left it on for a couple of hours. Returned and hey presto, the humidity was now down to 60, temp went up to 14C and the droplets/condensation on the felt seemed to have evaporated ..great success (Borat)

    In the meanwhile, I pulled all the insulation back, the ones which I feel had blocked the eaves

    Not 100% sure they were blocked but yes possibly. There were other areas in the loft, where the insulation had definitely not caused any blockages.

    Sunday was much better. Switched off the humidifier and the heating and re-checked the temp. It was around 5 C and the humidity around 85%, which was the same as outside. So I presume airflow is present, from interior to exterior, if both have the same humidity?

    This is all from my end. Will repeat the same over the next weekend. In the meanwhile, I hope my felt lap vents will finally arrive and may make a difference. Or as Jonathan said, could be just related to the cold snap and me vigorously pushing the insulation into the eaves. Fingers crossed but the dampness is not to be taken lightly, seen mould grow like wildfire

    , if this is ignored



    pics? pre and post-insulation being moved

  • Daisy Rae
    3 months ago

    To avoid condensation in your attic/loft you must stop warm moist air rising from the living area into the loft space. Ensure there are as few gaps as possible around bathroom fan and light fittings etc. Check the loft hatch too - use cushioned insulation to fit around the door if you find gaps. This is especially important if you enter the attic regularly.

    You can use a fan (they’re cheap to run) to keep the air moving during cold snaps and a dehumidifier to trap the water. Always ensure your insulation allows air to circulate and make sure you have enough soffit (or other) vents.

    Ultimately your attic temperature should be as close to the outside temp as possible to avoid any excess moisture.

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