My loft is suddenly wet. (especially under the sloping roof on the front of the house). There are beads of water all over the inside of the roof .. I dont think its a leak but instead its condensation?? Has anyone else had this? The insulation up there is probably about 30 years old. I am thinking its heating escaping into the loft and causing this. Its never happened before. Not sure why its suddently happening. What should I do? I think I need to insulate it properly. Many thanks.
Loft Insulation
- Thread starter Skinybean
- Start date
Yes it's condenstation. The moisture probably comes from you, your family, the bathroom, drying washing etc etc.
Yes I had this pretty bad too. I sealed up a redundant loft hatch, applied sealant to every hole in the ceilings (ie where pipes and wires go up), and added soffit vents to keep the air circulating in the loft. It has done the trick.
Old plasterboard is very porous too, and if moisture from the bathroom is on the ceilings, it'll go through into the loft. Glass fibre insulation won't stop it, it'll just become wet, and therefore, pretty ineffective.
You need to look at reducing moisture production, check out the effectiveness of your insulation, and ensure there is good ventilation in your loft.
In my case, there is only one sensible thing to do: take down the plasterboard, fit 100mm of PU insulation, and fit new p/b, reskim. Lovely and warm!
Yes I had this pretty bad too. I sealed up a redundant loft hatch, applied sealant to every hole in the ceilings (ie where pipes and wires go up), and added soffit vents to keep the air circulating in the loft. It has done the trick.
Old plasterboard is very porous too, and if moisture from the bathroom is on the ceilings, it'll go through into the loft. Glass fibre insulation won't stop it, it'll just become wet, and therefore, pretty ineffective.
You need to look at reducing moisture production, check out the effectiveness of your insulation, and ensure there is good ventilation in your loft.
In my case, there is only one sensible thing to do: take down the plasterboard, fit 100mm of PU insulation, and fit new p/b, reskim. Lovely and warm!
Thanks for such quick response. Sound advice. I will get new insulation. When you say replace PB do you mean the plaster board? The inside of the roof is only lined with black stuff. Do I need to insulate inside the roof as well as between the floor joists? Also, you say the soffits have air vents, could these be blocked (perhaps birds nests or something??) Sorry if this sounds a bit pathetic. I am a woman and dont have much clue!! Many thanks
It doesn't sound pathetic at all.
It's very common to have condensation on the underside of traditional roofing felt (as opposed to the permeable membranes fitted nowadays) and cold weather will make it more apparent than usual.
To add to the advice you've been given: check that any water tanks in the loft are properly covered, as these can be a source of evaporated water; consider an extractor fan in the bathroom; fit a draught seal around the loft hatch.
It's very common to have condensation on the underside of traditional roofing felt (as opposed to the permeable membranes fitted nowadays) and cold weather will make it more apparent than usual.
To add to the advice you've been given: check that any water tanks in the loft are properly covered, as these can be a source of evaporated water; consider an extractor fan in the bathroom; fit a draught seal around the loft hatch.
Thank you very much. I have fitted a draught excluder around the loft hatch and I will make sure the kids know to always open the bathroom window when showering. I am borrowing my neighbours ladder in the morning to check my soffits. Hopefully I wont be posting a message for advice on the A&E website tomorrow!! Very many thanks for replies. xx
Just another little thought - I suspect lots of people with similar problems stuff loads more insulation in, and the insulation (if it's fibreglass) gets pushed right up against the roofing felt and blocks the air flow from the soffits then the problems get worse, not better.
Thats the tricky bit generally - making sure there is sufficient insulation AND sufficient ventilation right next to the eaves.
If you do go down the road of getting more fibreglass, you can also get spacers to keep it from touching the felt. In my case, I could have only fitted 100mm of fibreglass at that location, which is hopelessly inadequate, hence the need for PU insulation (eg Kingspan)
Thats the tricky bit generally - making sure there is sufficient insulation AND sufficient ventilation right next to the eaves.
If you do go down the road of getting more fibreglass, you can also get spacers to keep it from touching the felt. In my case, I could have only fitted 100mm of fibreglass at that location, which is hopelessly inadequate, hence the need for PU insulation (eg Kingspan)
You certainly don't need to replace plaster board.
Many lofts will experience condenstion on certain days and it makes no difference if this has never happened before. Its only a problem if this is persistant and extensive.
Increase insulation, which you should do any way. This will keep the loft cooler and reduce the possibility of warm air condensing
Ventilation - such as a couple of vent tiles to each side may help, but before you do that, try this instead ..... have a look at the underside of the felt where one row laps the other. Now its likely that the bitumen has stuck together. Try and lightly push your hand into the joins to separate them - do this in several places to the lower, central and top parts of the roof front and back
This will allow natural ventilation through the felt which is normally enough to allow air to circulate to dry off condenstion
Many lofts will experience condenstion on certain days and it makes no difference if this has never happened before. Its only a problem if this is persistant and extensive.
Increase insulation, which you should do any way. This will keep the loft cooler and reduce the possibility of warm air condensing
Ventilation - such as a couple of vent tiles to each side may help, but before you do that, try this instead ..... have a look at the underside of the felt where one row laps the other. Now its likely that the bitumen has stuck together. Try and lightly push your hand into the joins to separate them - do this in several places to the lower, central and top parts of the roof front and back
This will allow natural ventilation through the felt which is normally enough to allow air to circulate to dry off condenstion
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