Low Energy House - Insulated Plasterboard Dry Lining - Solid External Walls
The amount of heat lost through an un-insulated solid wall is more than double that of an un-insulated cavity wall
Solid Wall - Insulated Dry Lining
If the external walls of the house are constructed of solid masonry they can be lined internally with insulated plasterboard, to give a moderate upgrade. Rigid board insulation can be applied to the inside face of an external wall to make the wall more energy efficient.
Insulated Dry Lining and Building Regulations
The Building Regulations U-value target for the insulation of an external wall of an existing dwelling is 0.35 W/m²K.
In existing dwellings, if the target U-value cannot be achieved, it is important to achieve the
best insulation levels possible in order to improve comfort and reduce energy bills. Detailed information on the thicknesses of insulation and heat loss calculations for particular
types of building construction can be obtained from insulation manufacturers.
Insulated Plasterboard Dry Lining
The most popular system of solid wall insulation uses sheets of plasterboard bonded with an insulant. Most systems have their own integral vapour check to protect them from condensation damage. The sheets, depending on the type of insulation, are available in thicknesses from 15mm to 65mm. They can be used to line the inside of existing walls either onto the existing plasterwork, if it is in good condition and well bonded, or directly onto the brick or blockwork face.
When in position, the plasterboard joints can be skimmed with board finish plaster or, with the
joints filled, they can be lined with paper and decorated.
Types of Insulated Plasterboard Dry Lining
Insulated plasterboard sheets are available laminated with a variety of insulating materials and in a variety of thicknesses:
- Expanded polystyrene insulant - total board thicknesses from 22mm to 50mm including integral vapour check
- Extruded polystyrene insulant – total board thicknesses from 27mm to 55mm
(the closed structure of the foam insulant provides a vapour check)
- High performance phenolic foam insulant – total board thicknesses 50mm to 65mm with
vapour check as standard
Insulated Plasterboard Dry Lining - Vapour Check
It is important to ensure that the vapour resistance is adequate.
Dry Lining Window and Door Reveals
The insulated dry lining system must be continuous into the reveals of windows and external door
frames. To facilitate this, without encroaching too far onto the window frame, thin boards (18mm thickness), insulated with phenolic foam are manufactured for this purpose.
Unsuitability of Dry Lining Systems in Certain Conditions
Dry lining systems are not suitable for use in areas subject to continuously damp or humid conditions.
To Determine Whether or Not Your External Walls Have a Cavity - Link to - Cavity or Solid Wall?
Up to 35 per cent of all the heat lost from un-insulated homes passes through the external walls
