Period Timber Windows and Slimlite Double Glazing

Timber provides one of the best insulation values of any material used in the construction of a window.

Most timber windows in the past and even recently have been single glazed because of the inability of bulky standard double glazed units with 10mm deep perimeter seals to be glazed into timber windows particularly with astragals and not acceptable by Planning Authorities for conservation, listed or graded buildings.

This new innovative Slimlite Double Glazed Unit opens up many possibilities for the manufacturer of timber windows.

It is no longer necessary to apply adhesive astragals to a standard double glazed unit to effect a ‘Georgian Look’ as Slimlites will fit into the rebates of an astragal which usually has a 7mm rebate depth, which prevents the 5mm overall perimeter seal being visible and a rebate astragal width of around 20mm which can accommodate a Slimlite overall thickness of 12mm with a front putty or bead of around 6mm or more. There is of course enormous potential in the replacement of Slimlite into single glazed windows, as Slimlite will fit into most single glazing rebates.

                                                                                                    Slimlite sealed units are the slimmest units

                                                                                                    available offering a U-Value of 1.9 and below

Most timber windows constructed for single glazing would have rebate depths of at least 7mm and glazing width rebate of approximately 20mm (see sketch).

New technology Slimlite Double Glazed Units with a 5mm perimeter seal depth and overall thickness of 12mm, can be glazed into most single glazing rebates or new timber windows which are manufactured to maintain the slim astragal appeal.

When Slimlite Double Glazed Units are glazed into a timber window, they are undetectable unless from close up examination.

Given the Governments drive to reduce carbon dioxide emissions, Planning and Conservation Authorities should consider the use of Slimlite Double Glazed Units in Conservation and Listed or Graded Buildings as there is no change to the physical appearance of a window, but provides serious reduction in energy requirement and therefore reduction in carbon dioxide emissions.