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How to Board your Loft Guide

Want to know how to board your loft? then you have come to the right place.  Our skilled tradesmen have boarded many lofts in Essex and London.  This article covers everything you need to know about how to board your loft.  We take into account insulation requirements, storage and access.

Why Board out your Loft?

  • Is an ideal solution for anyone wanting extra storage space.
  • Is a great way to access heating pipes and electrical connections.  But only if boards are planned out carefully.
  • Makes the loft safer to walk around in.  You do not have to worry about watching your step.
  • These days Energy Performance Certificates (EPC) are needed when people buy or sell houses.  These certificates grade the energy efficiency of your home.  Better insulation properties will help improve your EPC grade, meaning your home is more efficient to run. Energy efficient homes are less expensive to run.

Before you follow our ‘how to board your loft guide below’, check out the list of materials and tools needed to complete the job.

List of Materials

Loft Legs

Used to raise the floor by 175 mm, so that insulation can fit underneath.  Loft legs are very strong, each can take a load of up to 500kg.  However, please check how much load your joists can handle if you plan to store incredibly heaver things in your loft space. They can be spaced apart a maximum of 600mm.

how to board your loft guide loft legs

Loft Boards

These boards have a tongue and grove system, which means they simply slot together.  The separate boards are narrow enough to get through your loft hatch.

Loft Wool Insulation (100 mm)

This insulation has a thickness of 100 mm.  This is ideal to install between ceiling joists, as most are 100 mm thick.

Loft Wool Insulation (200 mm)

This insulation has a thickness of 200 mm.  This is ideal to install 90 degrees to any wool that exists between the joist.  It will mean you have 300 mm of wool insulation.


These screws are suitable for fixing tongue and groove boards to loft legs.  They can also be used to fix loft legs to the joists.

List of Tools

Milwaukee Compact Drill

An excellent cordless drill popular with building contractors.  This powerful Milwaukee drill comes with charger and case.

Pozi Drive Drill Bits 

Many screws are required when it comes to loft boarding.  You will need 8 screws per loft leg.  4 screws to fix the loft leg to the joist.  And another 4 to fix the loft board to the loft leg. Pozi drive drill bits enable you to use a cordless drill as a powerful screwdriver.

Tape Measure

You will need to measure up to determine how many boards you need.

Lift of Safety wear

Quality Dust Mask

Loft boarding involves moving insulation around.  Usually insulation is of the glass fibre wool type.  This type of insulation is harmful to your lungs if breathed in.  Please do the sensible thing and ensure you wear protection.


If installing glass fibre wool, then googles are a must.  It will prevent your eyes from being irritated by the insulation.

Disposable Paper Suit

If you do not wear a coat or a paper suit, you are guaranteed to feel very itchy after.  These disposable suits are also handy for other types of jobs such as decorating.

Important Notes before Boarding a Loft

Building Regulations UK

Planning permission is not required to board out a loft for the purpose of loft storage.  Planning is only required if you are wanting to convert your loft into a living space, such as carrying out a loft conversion.

Insulation requirements for lofts have increased dramatically throughout the years.  Below you can see how insulation thickness has increased throughout the years.

1950’s = 0mm glass mineral wool insulation requirement

1965 = 25mm glass mineral wool insulation requirement

1975 = 60mm glass mineral wool insulation requirement

1985 = 100mm glass mineral wool insulation requirement

1990 = 150mm glass mineral wool insulation requirement

1995 = 200mm glass mineral wool insulation requirement

2002 = 250mm glass mineral wool insulation requirement

2003 = 270mm glass mineral wool insulation requirement

If your home is more than 10 years old, its likely you will benefit from extra insulation.  The largest majority of heat lost from a building is via the roof.  The purpose of loft insulation is to slow down the heat loss process.  Loft insulation can also save you a lot of money on heating bills per year.

All new homes are built to the insulation building regulations of the time.  Building regulations do not require older homes to have insulation, but does recommend it.  If you live in the UK, you can visit the Planning Portal website for more regulations regarding loft insualtion.

Utilities within your Loft Space

Do you have water or gas pipes in your loft? If so then ensure you board around them to ensure easy access.  If a water pipe bursts the last thing you want is to be ripping up your loft boards.  This also applies to important electrical connection, such as light fittings and junction boxes.  

Down Lights (Recessed Lights)

The modern trend is to install down lights.  However, such lighting does have a negative effect on insulation properties due to the amount of down lights required.  Building regulations require a gap between your down lights and insulation.  A generous gap ensures the down light will not overheat.  Did you know that LED down lights can get very hot too due to there large heat sinks?

Fortunately there are companies which sell down light covers that are fire retardant, and draft proofing.

Plastic Down Light Covers

how to board your loft downlights

Mineral Fibre Down Light Covers

Loft Access

Be aware your floor will be raised by 175mm via loft legs when installing your flooring. Ideally you should lower the floor level next to the hatch, this only needs to be a ledge you can climb onto.  It will make life easier gaining access to your loft.

Types of Insulation

There are many differences between insulation.  Warton Woodworks only use insulation wool, space blanket or PIR insulation boards.  PIR foam board is more effective then glass wool by a factor of 2.  This means 100mm of PIR is equivalent to 200mm of glass fibre wool.

Usually customers go for standard glass fibre insulation.  It is the most cost effective solution.

Loft Ventilation

The more insulated your house is, the colder your loft will be.  This is because the insulation is slowing down the heat trying to escape your house.  A colder loft does also means warm moist air can condensate within the loft.

To solve this problem you must ensure:

  1. You reduce the amount of moist air within your home.  Activities such as showering, cooking a dryer clothes create moisture.  Any moist air within your home will raise when heating, thus entering your loft space.  Make sure you install extractor fans in your bathroom and kitchen.  Ideally you should choose extractors that directly vent to the outside, rather than recirculating ones.
  2. Make sure your loft space have adequate ventilation.  Ideally there should be a cross flow of air in your loft, from one eave to another.  The air enters your loft via the soffit boards within the eaves.

Joist Spaces and Loads

The loft legs used in this guide are incredibly strong, and can handle loads up to 500kg per loft leg. However, before converting your loft into storage space you must first consider how much weight your loft joists are designed to handle. It is usually ok to store general household items such as Christmas trees, books, clothes, boxes, portable electrical items, etc. But if you plan to store something ridiculously heavy, then please do your research regarding your joists first!

The loft legs can be spread apart a maximum distance of 600mm centres. This means they are ideal for joists that are spaced 600mm or under. The diagrams in this post show how to install loft legs for 300mm joists, just to give you an idea of how you go about installing them.

How to Board your Loft – Step by Step Guide

Step 1 – Remove the Old Insulation

Note:  Only do this step if the old insulation has been damp due to water leakage.  Or if the insulation looks like it could cause a fire hazard, such as having incredibly large amounts of dust collected on top.

  • If you have very old insulation, consider starting from scratch.  Once all is removed you can vacuum between the joists.  Expect much dust and insulation particles.  Also look out for old nests or hives.  Once all the insulation is removed you should then be able to see the plasterboard ceilings underneath.  The diagram below shows you an example of a loft:

how to board your loft guide

Step 2 – Lay 100mm Insulation Between the Joists

Note:  Do this step only if step 1 was carried out.

  • Roll out 100mm thickness glass mineral wool insulation between every joist within your loft.  The top of your insulation should almost be flush with the top surface of the joists.  Ensure this insulation is not covering your cavity wall gap.

how to board your loft

Step 3 – Plan the Location of your Loft Boarding

  • Decide where in the loft you want your boarding.  Your decision will be influenced by the shape and size of your loft.  There may also be obstructions such as vertical beams at awkward angles.
  • Try to place your loft boarding area close to the loft hatch.
  • Choose an area where there are no water pipes, electrical junction boxes, light fittings or anything else you may need access too.  If you board over such things it will be difficult to reach in the future.

Step 4 – Plan the Size of your Loft Boarded Area

  • Decide whether or not the whole loft needs to be boarded.  Many people only board a small area of the loft to keep costs low.  Also the amount of boarding should depend on how much you want to store.      

Step 5 – Install a Loft Hatch Entrance Board

  • Lay a piece of plywood (cut to suit) adjacent to the loft hatch.  This will make it easier to climb into the loft via your ladder.  The diagram below provides an example of where your plywood could be fixed down.

Step 6 – Install the Loft Legs

  • In order to achieve over 100mm of insulation, you will need to raise your loft boarding. This can be done using loft legs.
  • Screw the loft legs directly into your floor joists.  Space them 1m apart along the joists.  They should be fixed along every joist the floor will be.  Joists are usually spaced about 300mm apart.  This means you will have loft legs 300mm apart between joists, and 1m apart along the joists.

how to board your loft guide diagram

Step 7 – Lay Insulation Between the loft Legs

  • Insulation requirements for homes have increased dramatically over the years.  Most older homes have insulation between the joists only, usually 100mm high.  Loft boards were simply laid on top of the joists then screwed in.  Current insulation requirements recommended by the Energy Saving Trust are 270mm.  This figure is based on glass fibre wool insulation.
  • The 175mm loft legs you have installed allows a total depth of 300mm of insulation (glass wool).
  • If you currently do not have any insulation, lay 100mm of glass fibre wool between every loft joist.  Cut the wool to the correct length and width.
  • This means you will have 100mm of glass mineral wool between your joists.  Then you will have 200mm of glass mineral wall 90 degrees to this, between your loft legs.  Like the image below, however this particular loft used space blanket insulation.  This is basically glass fibre wool wrapped in aluminum foil:

how to board your loft guide diagramAdding on an extra 200mm of insulation

The image represents an area in your loft that will not have loft boarding.  The insulation used is called space blanket.  This is simply glass mineral wool wrapped in foil.  The purpose of the foil is to trap the glass fibres inside, making your loft air cleaner.  It also makes the job easier and less itchy.  As in the diagram above there is 100mm of insulation between the joists.  Then 200mm thickness insulation is laid about at 90 degrees to the one underneath.  

  • 300mm of loft insulation means you have achieved over the recommended 270mm of insulation.
  • Please note that 150mm of PIR foam board insulation is equivalent to 300mm of glass mineral wool.  However, mineral is a much cheaper solution.

Step 8 – Installing the Loft Boards

  • Screw your first loft board down on top of your loft legs, close to the loft hatch.  Use 2 screws per loft leg to fix the boards down. One board should have a total of 8 screws in it.  

how to board your loft guide

  • Slide the second loft board into place, so that it joins to the first one.
  • Make sure the orientation of the loft board is correct.  Tongue and groove boards are designed to slot together.
  • Now screw the board into the legs beneath it using 2 per leg.  This board should also have a total of 8 screws fixed into the loft legs.

  • Repeat this process until you lay all of your loft boards.

how to board your loft guidehow to board your loftThe image has a total of 300mm of space blanket insulation.  This is glass mineral wool wrapped in aluminium foil.  The purpose of the foil is to help prevent the glass fibres from flowing through the air.

  • You have now completed the how to board your loft guide.

 How to board your loft using different insulation

List of Materials

Below is some alternative insulation that can be used within lofts.

Space blanket

Space blanket is glass fibre wool wrapped in aluminium foil.  It offers more protection against itchy fibers, making it more comfortable to lay.  It also have a heat reflective foil surrounding it.

PIR Board Insulation (Kingspan)

PIR board is twice as efficient then glass fibre wool.  Therefore 100mm of kingspan is the same as 200mm of fibre glass wool insulation.  This may be a good option if your loft space lacks height, or you want a neater finish.  The great thing about this type of insulation is that it creates a tight seal, as its cut to size.

Examples of Different Insulation being used

Below is a picture of loft legs being used with space blanket insulation.  Loft legs are spaced about 30cm apart between every joist.  Tongue and Groove chip board is then screwed to the loft legs.

how to board your loftBelow is an image of a loft being topped up with more insulation.  After we installed space blanket insulation between the rafters, we then placed 200mm space blanket on top.  Always make sure you apply more insulation cross ways (90 degree’s to the insulation underneath).  This helps to prevent cold spots within your loft.

Adding on an extra 200mm of insulation

Below is an image of a loft entrance.  Floor level is lower at the loft entrance compared to the storage area.  This ensures easy loft access.  PIR foam board (kingspan) insulation has been installed around the loft entrance.  This customer wanted the very best insulation above his cold bathroom.  Other areas of this loft use space blanket.  The kingspan insulation also allow the customers to freely walk around his loft where no flooring is present.

how yo board your loft guide celotex

We hope you enjoyed this how to board your loft guide.  Please feel free to share it!

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We done a hip to gable loft conversion on the bungalow, in the image below.  See how we done it step by step, includes over 100 images from architect drawings to completion. 


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