Lawtech Ltd can supply and install internal wall insulation. There are two main ways to insulate a solid wall internally – either with rigid insulation boards, or a stud wall.

Consider condensation. Condensation occurs when warm air from inside your home meets a cold surface. When you fit internal wall insulation it stops the heat from your home reaching the wall so the wall will be a lot cooler. When insulation is applied on the inside of your external wall, a vapour barrier is applied to prevent moisture from the air in your home forming on the cold exterior wall.

The first step is to assess the condition of your existing indoor walls. If repairs are needed, they will have to take place before installing insulation. Any problems with penetrating or rising damp must be resolved in advance, as these both arise from defects within the building structure. Insulation should not in any circumstances be used to cover, hide or isolate damp. This could lead to more serious problems in the future. An installer will be able to advise on this.

With internal wall insulation, consideration must be given to supporting heavy fixtures like kitchen units, radiators or wash basins. If there are no such items to be supported, then you can fit rigid insulation boards. However if there are, you may be best installing a stud wall.

Insulation direct to the wall involves fitting plasterboard backed with rigid insulation onto the inside of walls. Typically the insulation will be made of either expanded or extruded polystyrene (EPS or XPS), polyurethane or phenolic foam. The insulation should be at least 60mm thick to meet recommended standards, and can be anything up to 100mm thick.

Before installation, it is crucial to prepare the wall that is to be insulated; its surface needs to be flat. Where existing plaster has been removed and the brickwork is uneven, the wall must be made flat using a layer of plaster or render. Ask your installer if they do it as part of the job.

Once the wall is flat, the insulation boards can be fixed straight to it using continuous ribbons of plaster or adhesive. Additional fixings are used to hold the boards firm, and the joints between each board are sealed to prevent air leaking through to the solid wall.

With stud walls, a metal or wooden studwork frame is attached to the wall and filled in with mineral wool fibre and covered with plasterboard. It can then be plastered over, ready for redecoration.

Mineral wool insulation, which is also used to insulate lofts, is a less powerful insulator than rigid insulation boards. So, to provide the recommended level of insulation, the mineral wool ‘filling’ needs to be at least 120mm deep. This makes stud wall insulation thicker than rigid insulation boards, which means it will affect the size of your room a little more. But on the plus side, a stud wall is strong enough to hold heavy fittings. Rigid insulation boards, by contrast, would need lengthy mechanical fixings that reach all the way from whatever you might want to support to the outer solid wall.

For further information on internal wall insulation please contact us.

Lawtech is one of the largest installers of external wall insulation systems across the UK with offices in Rochester and Glasgow. Lawtech is UKAS accredited to ISO 9001 & ISO 14001 and is an active member of both the NIA & INCA.

Lawtech is able to act as a Principal Contractor on multi million pound “green” retrofit schemes installing and managing multiple energy saving measures, and in addition as a specialist façade contractor working with other contractor partners. We are able to offer advice and assistance in respect to grants and funds schemes available under CERT, CESP and from 2013 Green Deal.