Frequently Asked Questions

Frequently Asked Questions - OS Insulate

What is insulation?
Insulation helps keep your house warm in the same way that wearing a jacket or jumper helps to keep your body warm. If your home is often cold or hard to heat, it may be poorly insulated. Insulation can save money and energy in the home and ensures that the heat you pay for stays within your walls.
Why Insulate?
  • Save money on your fuel bills
  • Grants available to help with the cost as of April 2009
  • Adds value and salability to your home
  • Protects the environment and reduces CO2 emissions
Where does the heat go?
Most of your heat (32%) will be lost throughout your property's roof, followed by walls (27%) and through Ventilation systems (18%). However, windows and floors are also culprits and addressing your insulation needs will help combat all of this.
What is the U-value?
The U-value is the measure of the rate at which heat is lost through a wall or roof, for instance. As it is a measure of heat loss then the lower the U-value the better it is for your home.
How is the Attic Insulation installed?
Insulation is blown in, using an insulation hose, or rolled out across the attic space to a depth of approximately 270mm, which complies with current building regulations.
Some of my attic is floored, what should I do?
If you have existing flooring in your attic, it can be raised to a suitable level to allow the required amount of insulation to be fitted. Extra flooring space can also be provided, if required.
How long does it take to install attic insulation?
The average attic can be completed in about 2 hours.
Why insulate the attic?
Attic insulation acts as a blanket trapping heat rising from the living space below and can typically reduce heating costs by up to 20%. Attic insulation has a payback period of approximately 3 years.
What will I save by insulating my attic?
Insulating 50sq.m (540sq.ft.) of a typical house could save approximately €130 a year (up to 20% of your fuel heating bill) and so would pay for itself in about three years. (SEAI – A Detailed Guide to Insulating your Home)
Will there be any damage done to my ceiling during installation?
Absolutely none.
What is a cavity wall?
The external wall of a house is constructed of two masonry (brick or block) walls, with a cavity (gap) of at least 50mm between the two walls.
How is cavity wall insulation installed?
The cavity wall is injected with the insulating material by drilling a series of holes in the external wall. Holes are generally of 25mm in diameter (approx size of a €1 coin). Once the insulation is installed the holes are filled.
Will I be left with a series of holes in the exterior walls of my house?
Once installation is complete, the contractor will ensure all holes are filled.
My house already has Aero board in the cavity, can I fill the remainder of the Cavity with the Cavity Wall Insulation product?
Yes, the remainder of the cavity can be filled with Cavity Wall Insulation.
How long does it take?
Cavity Wall Insulation normally takes around 2 hours to install, but the length of time does depend on the size of the house and other factors such as access.
Is my house suitable?
Before installation, an experienced representative of OS Insulate will undertake an assessment of your property and confirm that it is suitable for insulation.
Do I have to do anything before installation?
The drilling process does create some vibration so it would be wise to remove ornaments, particularly near external walls, for their safety and your own peace of mind.
Is it a messy job?
The drilling process, during Cavity Wall insulation, inevitably creates a little dust, which will be cleared upon completion of the job. In order to make space for both our equipment & tools, you would also be advised to remove vehicles away from outside the property.
Does the Contractor have to come into the house?
The Contractor must undertake checks before and after installation, so it is essential that they have access to the inside of your property. Apart from these checks, all the remaining work is carried out from the outside.
My house is semi-detached, so how do I stop insulation going into my neighbour's cavity?
Assuming your neighbour's house is not already insulated, the contractor will insert a cavity barrier at the party wall line. If your neighbour's house is insulated at the same time, the cavity barrier is not needed.
Why insulate the walls?
Up to half the heat loss from a house occurs through the walls, this can be reduced by two thirds by insulating the walls. (SEAI – A Detailed Guide to Insulating your Home)
What will I save by insulating cavity walls?
The SEAI states that by insulating cavity walls you will have an annual fuel saving of between €100-€160, while the pay back period is between 4 and 7 years. (Saving are based on initial space heating costs of €650 excluding standing charges) (SEAI – A Detailed Guide to Insulating your Home)
Why should I fit a lagging jacket?
An 80mm lagging jacket can cut heat loss by 75% and could pay for itself in just a few months. If you're lagging jacket is less than 75mm thick, it is worth getting a new one.
Got additional questions?
Get in touch with our experienced team of insulators today by calling +353 86 894 4916 or emailing

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