In order for insulation to do its job, sufficient airflow to the outside surfaces is required. Good ventilation in your attic will allow the moisture to get out.
Insulation stops heat escaping from living spaces, so it will make your loft space cooler, which could introduce or worsen existing damp or condensation problems. If you are installing loft insulation yourself, please keep in mind that you may need to increase ventilation.
You'll need to start laying with a minimum gap of 25mm between the eaves and the insulation to ensure a suitable air gap. Maintain this gap along two opposite sides of the loft.
Loft insulation is not dangerous, at least when working with newer materials and with a professional installation. The majority of the dangers posed by loft insulation hinge on the installation process itself, which is why it's important to work with an accredited company.
Generally, it's safe to be in an attic with fiberglass insulation without a mask. Is it a good idea? No. It can get into your lungs and cause the coughing you're experiencing and can also irritate your throat.
Fiberglass insulation is made up of glass and plastic fibers. In the same way you don't want to touch fiberglass with your bare hands to avoid contact dermatitis, you do not want airborne loose-fill fiberglass particles in your lungs.
We recommend a FFP3-rated disposable dust mask when working in the loft, especially when handling or cutting loft insulation.
Should I remove old loft insulation before laying new? Older insulation material will typically need to be removed before adding new insulation. However, in some cases the material may be in good condition, meaning you can simply top up the existing insulation material for a fraction of the cost of a full replacement.
Air Leakage
Fiberglass insulation is less dense than other types of insulation and does not create an airtight seal, which means air can travel freely through the insulation. This is called air leakage and it's one of the most common sources of energy loss in a house.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
Fibre-based insulation, such as sheep's wool or hemp, works particularly well with old buildings. It has good thermal properties and, importantly, is 'breathable', although tends to cost more than mainstream products.
One important thing to remember is that insulation should never be pushed right into the eaves because it will interfere with airflow. If you're going for a warm loft then you'll need much more insulation to be able to cover the underside of the roof along with the gable and party walls.
One way that excessive loft insulation can cause dampness is by blocking ventilation. Proper ventilation is necessary to allow moisture to escape from the building. If insulation is installed too thickly or packed too tightly into the loft, it can block air flow and prevent moisture from escaping.
The ventilation must meet the all of following guidelines. There should be a clear 50mm of air space between the insulation and the roofing felt. If roof trimmers or hips restrict the passage of air from the eaves to the ridge, you can drill a series of 25mm holes into these members to allow a continuous airflow.
Generally, insulation should be breathable, especially if you live in an older home. This allows you to keep your home's structural integrity safe, protecting walls, floors, joists and rafters from mould, rot and structural damage.
Things to Know Before Installing Loft Insulation
An effective ventilation system within the loft is key to regulate airflow and prevent rot, damp, mould, and structural damage. If you plan on utilising the loft space for another purpose, install raised loft legs, leaving a minimum air gap of 50mm beneath each board.
Short-term Exposure
The symptoms of irritation are often nonspecific, temporary, and may include itching, coughing, or wheezing. High levels of exposure to airborne fiberglass may aggravate existing asthma or bronchitis-like conditions.
In general, the color of insulation doesn't equal better performance over another color. Whether it's pink, white, brown, or yellow—color doesn't influence dependability, reliability, or the products effectiveness.
Respiratory issues: Airborne particles of fibreglass, normally dislodged during installation, can cause mild to severe respiratory issues such as coughing, wheezing and even asthma attacks. Wearing an industry-standard facemask during installation is necessary to avoid this exposure.
Unless it's been damaged, loft insulation should last for around 80 to 100 years. It often depends on the material though. For example, spray foam insulation can last up to 80 years, while foamboard and mineral wool insulation can last a whole century before it needs replacing.
Lay out insulation rolls close together to prevent any gaps in your attic insulation. Go right to the edges of the loft space with your insulation to maximise its efficiency.
However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.
If you do not like the sensation of dirt or dust on your skin, you will want to wear gloves and cover exposed skin. The dust of cellulose can still be hazardous for your eyes and lungs. If you are near cellulose being installed and do not wear a mask, you will inhale dust and irritate your lungs.
Blown Fiberglass in Attics
Installers blowing insulation wear a NIOSH-approved filtering facepiece dust respirator (N95 or greater). No workers, unless they wear a NIOSH-approved filtering facepiece dust respirator (N95 or greater), should be permitted in the attic during or immediately after the application.
THERMAFLEECE Breather Membrane is light-weight 100 gsm breather membrane ideal for installing on top of loft insulation as a protective layer or under joints to hold insulation in position from below.