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Attic Insulation Thermal Response Heat Retention Window Insulation
In any attic conversion project, irrespective of the sub-division of the rooms, quality insulation is a critical factor.
Remember, you are turning roof space into living accommodation. In most cases, the house is not designed for that purpose and the roof was not insulated at the outset.
Today in rural Ireland, the most popular form of house is the dormer-bungalow, or as it is sometimes referred to, the 1½ storey house.
This design takes into account roof space from the start and utilizes it to the maximum.
Insulation material fitted to the house meets building regulation standards from the start so you are never likely to encounter problems on that score.
It is a different matter when you convert an attic in an existing house to living area.
Whenever the house was built, the floor of the attic was generally insulated to prevent heat escaping from the floor below. However, no attention was paid to the roof and mostly it is a layer of felt and the exterior slate or tile that are the only defence to the elements. Most roofs on houses over ten years old have bituminous felt fitted. This type of felt doesn’t breathe so account of this must be taken.
It is not good enough though to slap up insulation between the rafters, seal it off and leave it that. You have to allow at least a 50mm ventilation gap in order for the felt to breathe. You will need high performance attic insulation that is condensed so as not to take up too much head height.
This may require you to lift the tiles or slates and create that gap. If you are doing a complete transformation, where a new roof is being added, then this issue won’t arise as building regulations will ensure that an adequate amount and quality of insulation is fitted. You are advised to use felt such as Tyvek membrane in such situations as it does not require space to breathe
It is important that it is tightly fitted to each rafter; otherwise, you will suffer from an effect known as thermal looping, where hot air gets in behind insulation and reduces the ability of it to hold in heat.
On the floor of the attic, the existing insulation will have to improved or replaced. Whilst it may have been sufficient to keep heat escaping from the lower floor in the past, it now had the added task of diminishing sound and noise permeating down to the rooms below.
Pack rock wool or mineral wool insulation into the floor joist crevices and then lay at 25mm chipboard flooring to seal it in. Ideally, for sound insulation the room or rooms in the attic should have a quality carpet covering to lower footstep noise.
As in any project you embark on around the house, the extra money spent at the start to ensure quality insulation and heat retention, will return in multiple dividends over the years.
In 2009, the Government are introducing energy rating for all homes. An audit will be carried out of your hose and a rating is then applied. That quality of that rating is likely to effect the value of your home, so if you are doing something to the house before then check with the energy rating agency in the Department of the Environment to establish what you need to do to acquire a high rating.
http://www.atticconversionsireland.com reckons it could be a very cheap phone call!
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