How To Insulate Your Attic (2)
Insulating your attic is one of the most cost-effective ways to improve energy efficiency and comfort throughout your home. The right insulation helps reduce heat loss, lower energy bills and create a more consistent indoor temperature all year round.
In this attic insulation buying guide, we'll walk you through insulation types, attic flooring options and the essential products required for a successful installation. Whether you're tackling a DIY project or planning a larger home improvement upgrade, you'll find everything you need to choose the right solution for your attic.
How To Insulate Your Attic
See Attic Insulation Explained
Not sure which insulation is right for your project? Watch our in-store experts talk through some of the attic insulation products available at Chadwicks.
The short video provides practical guidance on insulation options, helping you better understand the materials commonly used when improving attic energy efficiency.
✔ WHAT DO I NEED TO INSULATE MY ATTIC?
Build your attic insulation shopping list below. Open each section to view insulation products, tools, PPE and project essentials before starting your attic insulation project.
ATTIC INSULATION
SAFETY & PPE
ACCESS & LIGHTING
TOOLS
OTHER ESSENTIALS
Guide Questions & Answers
Explore additional attic insulation guidance, planning information and commonly researched project questions.
What Types Of Attic Insulation Does Chadwicks Stock?
Chadwicks' attic insulation category currently lists three Knauf glass mineral wool loft rolls and a range of sheep's wool insulation products.
The Chadwicks range includes Knauf Combi Cut Loft Rolls in 100mm, 150mm and 200mm thicknesses. Chadwicks also stocks sheep's wool attic insulation products in a range of widths and thicknesses.
When comparing products, consider insulation thickness, pack coverage, product width and suitability for your attic construction and intended application.
Which Attic Insulation Is Right For Your Project?
The right insulation depends on your attic construction, existing insulation, ventilation requirements and how the attic will be used.
- Where the insulation will be installed
- What insulation is already present
- Required insulation thickness
- Ventilation requirements
- Future access requirements
- Tanks, services or equipment that need to remain accessible
There isn’t a single insulation product that suits every attic.
What Do Thermal Conductivity, U-Value And R-Value Mean?
Thermal Conductivity (λ): Describes how readily heat passes through an insulation material. Lower values indicate lower heat transfer.
U-Value: Measures heat transfer through a complete building element rather than the insulation material alone.
R-Value: Measures thermal resistance. Higher values indicate greater resistance to heat flow.
Thickness: Thickness is important, but overall roof performance depends on more than insulation thickness alone.
What Thickness Of Attic Insulation Do You Need?
A single insulation thickness is not suitable for every Irish home.
- Existing insulation levels
- Roof construction type
- Project objectives
- Available attic space
- Current Irish guidance and regulations
Always assess the existing construction and follow the manufacturer's installation instructions before selecting an insulation thickness.
How Much Insulation Do I Need?
Start by measuring the area that requires insulation.
Area to insulate (m²) ÷ coverage per pack (m²) = estimated packs required
Coverage varies depending on the product selected.
- Knauf Loft Roll 100mm – 13.89m²
- Knauf Loft Roll 150mm – 9.18m²
- Knauf Loft Roll 200mm – 6.84m²
Always check the current coverage shown on the specific product page before ordering.
Quick Project Summary
| Step | Tool / Product | Tip |
|---|---|---|
| Check Existing Insulation | Head Torch / Work Light | Inspect insulation depth, condition and any signs of damp before adding more insulation. |
| Measure The Area | Stanley Measuring Tape 8m | Measure the attic area and compare it with the pack coverage of your chosen insulation. |
| Gather Equipment | Utility Knife, Gloves and Dust Mask | Have all tools and PPE ready before starting to avoid repeated trips in and out of the attic. |
| Check Ventilation | Visual Inspection | Ensure ventilation openings and airflow routes will remain unobstructed. |
| Install Insulation | Stanley QuickSlide Pocket Utility Knife | Cut insulation accurately and avoid compressing it unnecessarily. |
| Protect Pipework | Pipe Insulation | Consider insulating exposed attic pipework where appropriate. |
| Maintain Access | Loft Ladder | Keep access routes to tanks, valves and services clear. |
| Final Check | Visual Inspection | Confirm coverage is consistent, ventilation remains clear and all services remain accessible. |
How To Insulate Your Attic: A Step-By-Step Guide
Ready to give your attic an upgrade? A little preparation goes a long way. Before you start, check what insulation is already there, work out how much you need and make sure the attic is suitable for the job.
For more complex roof constructions, electrical work, damp or ventilation issues, it’s best to get professional advice before getting stuck in.
Scope Out The Area
First off, have you got safe access to the attic? Somewhat crucial!
If you’re going to be up and down regularly, a loft ladder can make access a whole lot easier. Installing one can involve alterations around the attic opening, so if you’re not confident about the job or what’s involved, it’s one we’d recommend leaving to a professional.
Once you’re up there, have a proper look around. If lighting is limited, a head torch or work light will make life considerably easier. Get your dust mask and any other suitable PPE sorted before you start too.
Now check what insulation is already there and what condition it’s in. If you spot damp, leaks or condensation, don’t just cover them up with another layer of insulation.
Finally, take note of anything you’ll need to get to again, such as tanks, services or other equipment.
Measure Up
Tape measure at the ready.
Measure the area you’re planning to insulate and check the coverage per pack of your chosen insulation.
Area to insulate (m²) ÷ coverage per pack (m²) = estimated packs required
Different insulation products cover different areas, so check the individual product before ordering.
Measure twice, order once. Your hallway will thank you.
Get Your Gear Together
Nobody wants to get settled into an attic only to discover the utility knife is sitting on the kitchen table.
- Suitable gloves
- Respiratory protection
- Eye protection
- Utility knife
- Tape
- Head torch or work light
- Heavy-duty rubble sacks for clean-up
Have your insulation ready too, ideally after checking that you’ve got the right type, thickness and quantity for the job.
Check Your Ventilation
Here’s an important one. Your attic still needs to breathe.
Before adding insulation, identify ventilation openings and airflow routes and make sure you understand which areas need to remain clear.
Time To Get Insulating
Happy with the attic? Measured up? Gear on? Grand.
Follow the installation instructions for the particular insulation you’ve chosen and make sure it’s suitable for your attic construction.
For insulation being installed at ceiling level, work methodically across the area, aiming for consistent coverage and taking care around edges, services and awkward spaces.
Avoid unnecessarily compressing the insulation, and don’t cover anything that needs ventilation or future access.
Don't Forget The Pipes
While you’re up there, have a look at any exposed pipework.
If appropriate for your installation, this can be a handy time to tackle pipe insulation too.
Think About Future You
Before you finish, think about how you’re going to use the attic afterwards.
Need access to tanks or other services? Planning to use part of the space for storage? Going to be back up there regularly?
The Glamorous Bit: Clean Up
Gather up packaging, offcuts and other waste and leave the area tidy.
Heavy-duty rubble sacks are particularly handy here.
One Last Check
- Consistent insulation coverage
- Required ventilation openings are clear
- Services you may need again remain accessible
- No packaging or offcuts left lying around
- Product installation guidance has been followed
Everything happy?
Job done. Kettle on.All recommended insulation products, tools, PPE, attic ladders and project essentials can be found in the shopping list above.
