Tuesday, 30^th May, 2006

Re;    Attic insulation

Accessed via an enclosed staircase, the top floor accommodates a bedroom. This area has a flat roof with roof light and a small dormer window to the front. A door provides access to the rest of the attic space, which encloses the bedroom on three sides. This eaves space contains a roof light located above a glazed ceiling panel providing light to the stair well below.

Insulation.

The ceilings beneath the eaves space currently have a thin layer of mineral wool insulation between the rafters although there are no more than a few inches and frequent gaps leave some areas completely un-insulated. The attic bedroom’s flat roof and dormer are inaccessible but are likely to be poorly insulated, if at all. The bedroom’s walls adjoining the eaves space have little or no insulation. Where applied, the insulation is very loose and can contribute no benefit. The sloping ceiling above the stair access has no insulation.

I would recommend that you:
-consolidate the existing mineral wool ceiling insulation by reusing the ineffective vertically applied insulation to plug the gaps. Then apply further layers of insulation to achieve a minimum of 300 mm total thickness. This is by far the easiest improvement and therefore should be applied as liberally as possible.
-re-insulate the walls adjoining the eaves space to a minimum of 200 mm. by insulating between the timber studs then overlaying further insulation held with counter  battens.
-insulate sloping ceiling above stair access with 300 mm held with counter battens.
-further investigate the less accessible areas of the roof (the attic room’s dormer and roof)

Light well

The single glassed ceiling panel offers no thermal resistance between the heated interior of the house and the roof void (thermally ‘external’).

I would recommend that you:
- draught proof the glassed ceiling panel
- build an insulated stud partition wall between the double glazed roof light and the glazed ceiling panel. This would prevent heat loss to the large area of the attic space whilst improving the light reflected down the light well.

Skylight

The skylight in the attic bedroom also offers very poor thermal resistance.

I would recommend that you:
- enclose the skylight with a secondary glazing panel, preferably de-mountable to allow ventilation during summer.

Flat roof

The flat roof to the attic bedroom constitutes a large area of the roof and as such is a major source of concern. Insulating the flat roof from inside would be intrusive, so accessing it from outside would be better. This would also allow greater levels of insulation since it could be built up externally as well.

 I would recommend that you
- apply a combination of internal and external insulation to the flat roof.
- consider supplementing the external insulation with a green roof, which would have further thermal benefits and protect the roof.
- further investigate and consider possible options

Dormer

It is impossible to access the cheeks and roof void of the small dormer although the construction of the dormer is very thin, and as such it is probably un-insulated. Improvements are possible yet fairly intrusive for the potential advantage gained and so should be done when other intrusive work is carried out.

I would recommend that you:
- incorporate insulation of the dormer into work insulating the flat roof.
Eaves access door
I would recommend that:
- this door is insulated and draught proofed.

Storage

Installing deep layers of insulation covers the rafters and makes storage difficult.

I would recommend that you:
- create a storage deck whilst insulating the attic space, or
- build a boarded partitioned area within the attic space, perhaps incorporating the light well and attic access, to act as a buffer zone.

Some areas of concern are more easy to address than others. Where improvements are difficult or aesthetically undesirable they may be compensated for by over emphasis on easier or more unobtrusive measures.


Simon Lewis