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Five tips before you buy loft insulation

Posted by Dave Raval on 24 October 2018 at 9:13 am

It's easy to forget about your loft when you're looking at your home's energy efficiency. But the Energy Saving Trust point out that a quarter of heat is lost through the roof in an uninsulated home. With low levels not keeping enough heat in, it can have a serious impact.

But there's some key things to keep in mind before you go rushing out to rectify this. Here's a handy guide giving you some important points and key questions to ask about loft insulation.


1) What type of insulation to buy

There's a number of different insulation options on the market – but choosing the right one for your home can be difficult. If you're looking to fit insulation yourself, the best option is likely to be blanket insulation. This is typically made of mineral wool or fibreglass. These can be bought at many DIY stores and comes in pre-measured rolls. They can be easily rolled out, working with the majority of joist spacings in UK homes.

However, if your loft has joists that are more irregularly spaced, then loose fill insulation may be a better option. This can come loose in draughty lofts, however, so it's not always a perfect solution.

Finally, blown-fibre insulation can be an option for lofts with difficult access. The downside to this is that it must be installed by a professional, which makes it a more expensive option than blanket insulation, for example.
 

2) How much insulation do you need?

Many older homes in the UK have little to no loft insulation. If they do, it's frequently only to the height of your joists – typically around 75 to 100mm. The current recommended depth of loft insulation for UK homes is 270mm; topping insulation up to this amount can help make a significant saving on your energy bills.

There's no limit to the amount of loft insulation you can install, but typically savings scale down considerably over 300mm. This is reflected in purchasing options at DIY stores. Blanket insulation typically comes in rolls of 100mm (for between the joists) and 170-200mm (for laying over the joists).


3) Equipment for install

If you're planning to install loft insulation yourself, you must make sure you take adequate steps to protect yourself and avoid causing injury or damage to your home. Some types of insulation contain materials that can irritate, so it's always recommended to wear a face mask and gloves in order to protect yourself.

If you don't have sufficient lighting in your loft, consider purchasing a head torch or LED lighting which can help illuminate the area you are working in. To further minimise risk of damage, you should use crawl boards to safely install the insulation in areas. Walking on joists can be dangerous, especially narrow ones, and may lead to tripping and damage to the ceiling below.
 

4) Obstructions and cables

Before you install insulation in your loft, it's important to account for any obstructions or electrical cables that run through your loft. You should never insulate directly under a cold water tank, so factor this in to any calculations you're marking.

Similarly, insulation should never be rolled out directly on top of electrical cables or downlights. This can cause overheating and a potential fire risk. Lay cables on top of the insulation, and install downlight covers; this then allows you to roll the insulation out on top.


5) Using your loft after installing insulation

One issue to consider before installing loft insulation is how you are using your loft currently, or plan to use it afterwards. You cannot squash insulation with boards or boxes; research by the National Physical Laboratory shows that this halves its effectiveness. This leads to heat loss and negates energy saving.

There is a solution to this, however, which would be to install a raised loft floor above the insulation.

 

About the author:

Dave Raval is a SuperHome owner and is Chief Executive of one of LoftZone, a member installer of YouGen.

LoftZone StoreFloor is an award-winning system that allows for storage and safe access in your loft, whilst protecting the insulation underneath. It's approved for use by the BBA and suitable for nearly all homes, including new builds and lofts with irregular joists.

LoftZone are also offering 10% off all kits without boards to our readers. Use code “YOU10” in your cart from now until the end of November. 

If you have a question about anything in the above blog, please ask it in the comments section below.

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Comments

3 comments - read them below or add one

Ecohouseconvertor

EcohouseconvertorComment left on: 5 April 2019 at 2:41 pm

@rippa700 - I think that it would be better if YouGen pointed the banner ad to this page: http://www.yougen.co.uk/blog-entry/2849/Is+boarding+a+loft+with+LoftZone+the+easier+option'3F/

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rippa700

rippa700Comment left on: 1 March 2019 at 5:19 pm

Where's the info about installing raised floor above insulation as the banner ad suggests?

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RobertPalgrave

RobertPalgraveComment left on: 31 December 2018 at 5:57 pm

Insulation in lofts must be installed so that it doesn't block or restrict ventilation under the eaves. Condensation on the roofing felt is a likely consequence.

Another point worth attending to when doing this job is to insulate the loft access hatch AND to seal any significant points in the ceiling where warm moist air from below can find its way into the loft and again lead to condensation. Such as around bathroom extract fans vented on pipes through the loft, light fittings and of course the loft hatch itelf.

 

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