Insulate Your Own Loft
Insulating your loft is a task that most
competent DIYer’s can do.
My name is Rickie Dickson and I’ve been improving the insulation in lofts for over 20 years. I’m going to show you how to do the job safely, quickly and correctly. Insulating your loft is a fairly straightforward task, but there are a few things that you need to know so that the work is carried out trouble free.
Why you should insulate your loft to current recommended standards
By increasing your loft insulation to the
recommended minimum standard of 270mm (approx. 10.5 inches), your home
will be more comfortable and cheaper to heat. The cost of carrying
out the work will usually pay for itself within 3 years. Also if you
take advantage of some of the Government grants available, then the
payback period can be within one year, after which any savings is
money directly in your pocket. Lets face it, the gas and electric
suppliers make enough profit, your hard earn cash is better in your
pocket than theirs.
The equipment you will need
50mm duct tape
If your loft is large (over 80m2, then need pads are recommended
Right let’s get down to business.
First measure the size of the loft in square meters to determine the amount of material you will need.
TIP ..You don’t have to measure from in the loft, you can take the required measurements from the ground floor or by measuring from the outside whichever is easier, this is usually the same area as the loft space.
Whenever you go in the loft, if you don’t already know, you must only tread on the wooden joists. Do not thread on the ceiling… IT WILL NOT TAKE YOUR WEIGHT!
STEP 1: Insulate the tanks and any pipework
You need to make sure the pipes are adequately
insulated once you increase the insulation in the loft, as your loft
roof space will actually become colder. The common sizes of pipes in
the loft are 15mm and 22mm and occasionally 28mm. The pipe
insulation sizes that you will need are:
Most good DIY stores will supply the pipe insulation with the correct size insulation wall.
Layman guide to pipe sizes:
15mm (is about the diameter of a pound coin)
22mm (about the diameter of a 2 pence coin)
28mm (about the diameter of a 50 pence coin)
You need to fit the correct thickness of pipe insulation to give the maximum protection against freezing. Mitre the pipe insulation at 45 degree angle if you need to get around pipe bends then tape the pipe insulation about every metre with duct tape. If there are small sections of pipework where you can't get the pipe insulation on, such as pipes that are too close together, or near to stop cocks etc, then insulate these areas with some fibreglass insulation and secure loosely with duct tape.
IMPORTANT: You must ensure that there are NO gaps in the pipe insulation and no exposed pipes. Don’t skimp on this part of the job.
Example of poorly insulated pipework
STEP 2: Insulating the loft
Choice of materials
The most common types of insulation are
Glassfibre or Rockwool. Both products are non-combustible, although
Rockwool has a higher fire resistance. The best choice for a DIYer
however is Glassfibre. Don’t be worried by the name Glassfibre as
modern production methods now means they are virtually itch free.
Rockwool can be still be itchy and is more difficult to work with.
Glassfibre is lighter and each rolls covers more area than an
equivalent roll of Rockwool, so you will need less rolls to do the
It is better that you purchase the large rolls of 1200mm and not the encapsulated rolls.
Although the encapsulated rolls are marketed to the DIY market because they are itch free, they are normally sold in small rolls 400mm wide. If your joists width are not 400mm wide it makes it more difficult to do the job. I have also seen many lofts where condensation has been trapped in the foil backing of these rolls.
|The large 1200mm rolls can easily be accommodated to fit any joist width. Try to purchase multispilt or combi rolls. These are pre-cut and can easily be separated to fit either 400mm joists (common in houses built before 1970’s) or 600mm width joists (common in most houses after 1970). If your joist width are neither 400mm or 600mm or they vary, you can still cut the rolls to any size. Follow the tip below:|
|TIP.... Keep the insulation rolled up and cut it, as if cutting a swiss roll, by using a normal wood saw and cut it to the joist width you require before unrolling.|
Items that must not be covered by insulation
If you have any recessed lights in the ceiling then these must not be covered by the insulation. The insulation must be kept 75mm (3inches) away from the lights. The transformers for the lights must not be covered.
If you have any cables in the loft that serve either a power shower, cooker, or immersion heater, these also must not be covered by any insulation. Keep these cables above the insulation if there is sufficient slack. If not, or if they are fixed to a joist then the insulation must be kept 75mm (3 inches) away from these cables. These cables are easy to spot as they are a lot thicker than the other cables in the loft they are around 25mm (1 inch) wide. Any other cables are safe to be covered with insulation.
Laying the insulation
No existing insulation
50mm to 80mm existing
As previously mentioned you want the loft to be left a minimum of 270mm. inches. Ideally the first layer of the insulation needs to be brought up to the top of the. If you already have a layer up to the top of the joists then you only need to lay the second layer across the joists. The second layer then needs to be crosslaid across the joists. This will give you the maximum insulation effectiveness as well as avoiding any cold bridging that may occur from the ceiling joists.
Loft boarding and storage
If you need a certain
amount of the loft space for storage then allocate a section for
this. Around 20% of the loft for storage is adequate for most
people. The storage area will only be able to have the
insulation up to the top of the joists with a thickness of 100mm
(4 inches) you can board this area if required.
If your loft is already boarded you can lift the boards if you want to then follow the laying method above, but standard industry practice is to lay the insulation on top of the boards and just leave some of the boarded area to store your stuff.
It is possible to raise the depth of the joists to accommodate 270mm of insulation and then board all the loft to use for storage but this is expensive and outside the scoop of most DIY ers, so this won't be covered in this article.
Ventilation in lofts is very important, as poorly vented lofts can have problems with condensation. For more information...Click Here
It's always worth
checking out what grants are available, as you may even qualify
for free insulation or it may be cheaper to get a contractor in
than doing it yourself.
For current information on loft insulation and cavity wall insulation grants go to www.energygrantsdirect.co.uk
I hope that you have found this article helpful and good luck with the task.
If you which to use this site as a resource, please feel free to
create a link to it.