Don't Let Your Heat Slip Through the Roof

by Stephanie Borst
 

With temperatures dropping and Christmas approaching ever so  rapidly, heating is a commodity that few of us would like to miss.  We enjoy our lovely warm front rooms, comfortably looking out at the windswept trees and the drizzling rain.  But sometimes I simply can't help this feeling of the heat just slipping away.  In my inner eye I can see it like a golden flow, passing my feet going up, via the first floor, into the attic and away through the tiles into the blistering cold London night sky. And over and over, my environmental conscience instills this hard-to-quench feeling of guilt that the loft still isn't insulated properly. Well, our house is like so many, a very old house, dating from a time when energy was cheap and somehow other projects always pushed the question of insulation to the side.

But indeed, around 25% of the energy that fires our heaters silently disappears through an uninsulated loft, says the Energy Saving Trust in Great Britain. With energy prices rising nearly on a daily bases, the thought of  heating the night sky becomes increasingly difficult to bear, both  from an economic and an environmental perspective.   
But how difficult and costly is it really to insulate the loft? Let's have a closer look.
 
At first, I was quite surprised to learn that loft insulation  isn't nearly as difficult as I had imagined. No need for special tools, a well-stocked tool shed should contain all that's needed. A quick search on the internet comes up with dozens of DIY web pages that are bursting with hints, ideas, and solutions, but before you jump into your dungarees, there are a few things that need careful deliberation: 

• Can the loft be accessed easily and are the right tools at hand?  
• What's the condition of the roof?
• Is it in need of repair, are  there insects in the attic?
• Is it actually light enough to work up there for an extended period of time, and is there easy access to  electricity? 

Once all this is sorted out, we need to follow blissfully few basic rules. In order not to step through to the ceiling below and cause damage a suitable plank needs to be placed which supports our body weight, while insulation is being installed. Pipe work and water tank need an extra coat of insulation, as the temperatures will drop considerably in the loft after the insulating material is in place – it is a good idea not to insulate the surface below a water tank to prevent the tank from freezing in winter . Finally, if the water tanks are some distance from the loft hatch, it is probably necessary to set up a suitable walk board or similar to provide safe access.  

To adequately insulate your loft, the floor should be padded out with a layer  of at least 225 mm (9in) of insulation material, ideally 270mm (11in). The job itself is not very challenging –  the insulating mats are laid  out between the rafters horizontally and then another layer is placed over the rafters vertically to avoid the formation of thermal bridges, but first, of course we have to decide which insulating material we want to use.

Primarily you have to make  the choice between eco friendly and not so eco friendly material. While greener insulation material is generally slightly more expensive, it has the huge benefit of emitting fewer harmful  substances. This is an important consideration if you want to  use your loft for storage and it is also less harmful for the person doing the actual job.
One may choose between natural wool, hemp, flax and there is even insulation material made of recycled paper - none of which rank behind  the "Less Eco Friendly" choices when it comes to energy efficiency. The latest newcomer on  the market is insulation material made of recycled plastic bottles.

All of these are safe to handle and easy to install. If you would like to use your loft for storage, the most convenient solution is to insulate with the insulation mats between the  rafters, up to the joists and add special polystyrene boards as a combined flooring and second layer of insulation on top.  There are a number of these insulation boards (Expanded Polystyrene  EPS or extruded polystyrene XPS) on the market that are suitable to  walk on.  With this method you can achieve the right level of  insulation and a rigid surface, as long as the combined height of both layers adds up to at least 225 mm (9in)

Once insulated, there will be a noticeable difference in  temperature between loft and house, so that those who are looking  towards using the loft as a living space should think about  insulating the roof, rather than the loft. This is usually done by insulating between the   roof rafters using rigid insulation boards.  
To get an idea about the quality of insulation material, you can refer to the `U' and 'R' values in the product description. The 'U' value measures the amount of lost heat that traverses the  material -- the lower the U' value, the better. One generally assumes a 'U' value  of 2.3 without any insulation, which can be brought down to 0.16  with a 270 mm thick layer of high quality material – this means a reduction of heat loss  of about 95%. The 'R' value measures thermal resistance and can be combined for  various layers of insulation, so that here, a higher 'R'-value means  better insulation.

All in all, loft insulation is certainly a doable task, even for those  who are usually not so clever with their hands. But for people like  myself who finds it hard to drive a nail into the wall, it might be easier to check with the professionals.  

A large number of companies all over the country now offer loft  insulation, and moreover, they have the necessary expertise to help you tap into special purpose government grants.
With the so called Warm Front Scheme the  government indeed subsidises efforts to save energy and CO2 in England, mainly for those who receive benefits or are on a low income. Information leaflets and  application forms are available by post or via the website:
http://www.direct.gov.uk/en/MoneyTaxAndBenefits/BenefitsTaxCreditsAndOtherSupport/On_a_low_income/DG_10018661. You can call Eaga Partnership, the Warm Front Scheme Manager on  free phone 0800 316 2805.  As it stands at the moment though, the only materials being subsidised  are rock wool and fibre glass.

But how much does it cost to insulate your loft? The Energy Saving Trust has done the sums for us, and estimates an  average expense of about £350 for material which compares favourably with estimated energy savings totalling £145 per year -- that is, at current energy prices. Apart from the fact that loft insulation pays for itself in little  over two years, it also helps to curb carbon emissions by about 730  kg each year, and thus a considerably reduces our carbon footprint. These figures are based on a before and after comparison for an  average three bedroom semi-detached house, which has been fitted  with an insulation layer of 270 mm (11in).

On a national scale that means: If everyone in the UK installed 270mm loft insulation, we  could save around £520 million and would reduce carbon emission by three million tonnes of  CO2 each year.  
In other words, the combined amount of reduction in carbon dioxide  emissions would fill the entire Wembley stadium about 380 times!

For more information call the Energy Saving Trust advice centre on 0800 512 012 or check the website http://www.energysavingtrust.org.uk.

Posted By Katie

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http://www.ecohouseagent.com/Donald - totally agree, it's cheap and will more than pay for itself over a couple of years,

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Posted By Donald

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http://www.ecohouseagent.com/There's no excuse for not insulating your loft, there are grants available to everyone.

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Posted By Charles

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Great Article, I use loft insulation boards and they solve the problem with storage/insulation

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