What Do I Need to Insulate My Attic?

Attic Insulation Buying Guide

Plan Your Attic
Insulation Project

Compare insulation options, calculate quantities and build your complete attic insulation shopping list.

Attic Insulation Buying Guide

Plan Your Attic
Insulation Project

Compare insulation options, calculate quantities and build your complete attic insulation shopping list.

PROJECT SHOPPING LIST

✔ 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
Shop All Attic Insulation
Compare attic insulation options, thicknesses and coverage requirements for your project.
Attic Wool Insulation Range
Browse sheep's wool attic insulation products available in a range of widths and thicknesses.
Knauf Loft Roll 100mm
Suitable for insulating between attic joists.
Knauf Earthwool Loft Roll 150mm
Useful for increasing insulation depth.
Knauf Loft Roll 200mm
Suitable where additional insulation thickness is required.
SAFETY & PPE
ACCESS & LIGHTING
TOOLS
OTHER ESSENTIALS
PROJECT SHOPPING LIST

✔ 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
Shop All Attic Insulation
Compare attic insulation options, thicknesses and coverage requirements for your project.
Attic Wool Insulation Range
Browse sheep's wool attic insulation products available in a range of widths and thicknesses.
Knauf Loft Roll 100mm
Suitable for insulating between attic joists.
Knauf Earthwool Loft Roll 150mm
Useful for increasing insulation depth.
Knauf Loft Roll 200mm
Suitable where additional insulation thickness is required.
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?
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Which Attic Insulation Is Right For Your Project?
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What Do Thermal Conductivity, U-Value And R-Value Mean?
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What Thickness Of Attic Insulation Do You Need?
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How Much Insulation Do I Need?
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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.

1

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.

2

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.

Formula:
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.

3

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.

Don't Forget: All recommended tools, PPE and project essentials are linked in the shopping list above for a quicker shopping experience.
4

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.

Top Tip: When it comes to ventilation, more insulation isn’t automatically better insulation.
5

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.

Top Tip: No prizes for speed here. Take your time and do it neatly.
6

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.

7

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?

8

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.

9

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.
Ready To Get Started?

All recommended insulation products, tools, PPE, attic ladders and project essentials can be found in the shopping list above.
Important: This article provides general information only and is not a substitute for professional advice, a site-specific assessment or the manufacturer’s installation instructions. Every property is different. If you are unsure about the roof construction, safe access, structural condition, electrical services, damp, ventilation or the suitability of a product, stop and seek advice from an appropriately qualified professional. Always follow current product instructions and applicable building and safety requirements.