Condensation in Loft

If you have noticed moisture forming in your loft, attic or roof space you may have a problem with condensation. This has become a more common problem since the widespread use of double glazing and deep loft insulation, if good ventilation is not maintained. Moisture rises up through the property and enters the loft space via the ceiling, loft hatch or uncovered downlighters. If left untreated it can lead to black mould growth and other structural problems such as woodworm, wet rot and dry rot.

Lofts are designed with ventilation at eaves, ridge or through breathable felt, but sometimes this can become blocked, meaning any moisture in the loft is unable to escape, and will condense on cold surfaces like roof timbers.

If your property has had sprayed foam loft insulation installed either to secure damaged tiles or to provide insulation, always seek professional advice before taking any corrective actions. You may be able to take steps to solve the excess moisture affecting your loft space, but if the problem persists you may require professional help in the form of a condensation survey.

If moisture is unable to escape your loft space, it will remain trapped and will condense on cool surfaces. This means you need to remove excessive moisture from the loft space, and increase ventilation.

Here are some causes of condensation in lofts and attic spaces our surveyors come across regularly:

Here are some tips to prevent condensation forming in your loft space.

• Make sure you check your attic space has enough ventilation, with sufficient vents or air bricks. Good air flow will prevent stale air from condensing while improvements to ventilation will help warm air escape in summer.
• Double check insulation isn’t blocking soffit ventilation when it has been fitted.
• Move stored goods so they are not blocking air flow.
• Double check any water tanks have lids correctly fitted.
• Make sure moisture from the property below isn’t rising up into the loft space. If you are having problems with damp and mould across the whole house you may need to address this with improved ventilation and reductions to moisture creation. To get rid of condensation you can take steps including drying clothes outdoors, using lids on pans while cooking, and keeping trickle vents open.

To get rid of mould in your loft, you need to address the source of moisture that is causing mould spores to germinate. By improving ventilation you will allow trapped moisture to escape, preventing a future problem. Double check insulation is not blocking any vents in your loft space. The mould can then be manually wiped away with a mix of bleach and water. Make sure to wring out the cloth into a sink to prevent moisture reentering the atmosphere in your property.

If the problem persists you may require a condensation survey to fully understand the internal environment inside your property, with advice and recommendations from a qualified professional.

Loft hatches will prevent moisture from entering the loft space from the property below. Sometimes loft hatches can become mouldy as they provide a cold surface for moisture inside the property to condense on. To solve this issue you will need to address the cold loft hatch by improving insulation. This can be done by insulating the loft hatch with a layer of insulation such as foam boards or wool insulation.

In some properties there are two loft hatches, one above the other at ceiling and loft floor level. If both are not insulated, condensation will form in the void between them and shower downwards.

When carrying out repairs, fitting lights or any other manner of task that requires insulation to be removed in the loft, make sure that you place the insulation back down property. Otherwise cold spots can form where the insulation is missing, allowing for warm moist air to condense on this cold surface.

If insulation is missing from a ceiling, but there is not a constant issue with moisture production in the property, mould will not form on the cold bridge. However, what will happen over an extended period is dust will attach to the slightly damp surface of the ceiling. This dust shadow will be an image of the issue in the loft.

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  Is it normal to have condensation in lofts?

  Condensation in lofts is a problem that affects many properties in the UK every year, but it is not normal and will need to be addressed. It is caused because moisture is trapped in the loft space, without adequate ventilation to allow for it to escape. You will need to understand where the moisture is coming from, and how to prevent it. If left, this can lead to problems such as black mould, wet rot or dry rot, leading to potential costly structural repairs in the future.

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  How do I fix condensation in my attic?

  To fix a condensation problem in your attic you must first increase the ventilation so trapped moisture can escape, while trying to reduce the amount of moisture able to enter the attic space. Double check that insulation is not blocking existing vents, or consider installing additional vents to help air circulate. Make sure loft hatches are closed to prevent moisture flowing into the attic, and use extractor fans when cooking and cleaning to reduce the amount of moisture in the air.

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  Should I worry about condensation in the attic?

  If you have condensation in your attic you may be worried, but you can carry out simple steps to help prevent it occurring. Make sure there is enough ventilation to allow moisture to escape, either double check existing vents aren’t blocked or install new vents. Make sure insulation and stored goods aren’t blocking air flow. If the problem persists you may require professional advice to prevent the problem. If left untreated a condensation problem could lead to structural problems such as fungal decay, which can be very worrying for homeowners.

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  Is it normal to have condensation in the loft in winter?

  Properties are more likely to have a condensation problem in winter, and that is the same for loft spaces. It is however essential to prevent this problem as it can cause structural damage if not addressed. Colder weather means that there is an imbalance of temperatures between the warm air inside a property and cold surfaces, meaning condensation is more likely to form. Lofts should have adequate ventilation to allow for any trapped moisture to escape, stopping it from condensing on cold surfaces.