Timber Door Specifications for London and Surrey

Hardwood and redwood are ideally suited to doors. Both timbers suit different applications and have varying life spans and maintenance cycles. As a rule of thumb, hardy softwoods such as Nordic redwood and Accoya are well-suited, especially if they are to be painted. On the other hand, hardwoods such as sapele, meranti and oak have gorgeous tight grains that are commonly used for doors destined to be varnished.

Laminated Redwood and Accoya are less likely to twist and warp due to their cell structures; as such, they hold their paint well and the dynamic stability means you can fit multi-point locking systems without the worry of draughts.

Hardwoods can last longer, but generally require more maintenance. They’ll need frequent painting cycles due to resin bleeds and are prone to twist and warp a little more. Typically, laminated redwood on hardwood sills is a more economical option (with the exception of Accoya).

To prolong the painting cycle and life expectancy of your frames, hardware and double-glazed sealed units, we’d recommend installing dynamically stable frames. They won’t twist or warp, and are created by taking the sawn timber through an additional process called cross grain lamination. This involves the timber being cut into strips, then bonded back together with the grains facing opposite directions.

The result is a counteraction of the natural twisting process, as each of the bonded strips will move in opposite directions. The high-tech bonding adhesive used in the ‘lamination’ process is actually stronger than the timber itself, and acts as an additional moisture barrier.

Our approved network of manufacturers offer both double and triple glazed doors. That said, and contrary to popular belief, triple glazing is only marginally better for heat retention and no better for soundproofing. Research actually shows that a 16mm air gap between two panes of glass is the optimum cavity width for heat retention in your home.

The real influences on thermal and acoustic performance occur when invisible metallic coatings or PVB interlayers are added to the inner and/or outer glass panes. These coatings either reduce or increase solar gain (depending on what you need!). In addition to minimising heat loss, these can also help to reduce condensation and improve security and sound-proofing.

The general consensus among industry specialists is that argon gas-filled standard triple glazing, with one low-e glass pane, adds unnecessary weight and cost to opening sashes. Similarly, there is a negligible performance gain compared to high-performance double-glazed units.

Independent research has shown that good quality, factory-finished exterior joinery has up to twice the service life of standard joinery doors (if best practice design and manufacturing principles are followed).

One of the secrets to long-life performance and minimal servicing is to glaze and paint the doors in a controlled factory setting rather than on site. All of London Timber Windows and Doors Ltd’ approved manufacturers factory-finish each door to the highest standards, using only high-specification preservatives, paints and sealants.

Standard joinery is usually painted with one undercoat and two top coats. Our premium joinery, however, is specified at four coats or three thicker coats. A four-coat process often comprises either one undercoat and three top coats or one timber preservative coat, one undercoat and two top coats. Painted using the premium paint product Teknos microporous paint, it means that that your joinery will not need to be repainted for at least 7-12 years, compared to the standard 2-4 years.

This high-performance paint will degrade at 50 microns per year (each coat equates to approx. 250 microns) and is heavily pigmented to prevent harmful UV rays from degrading the lignin on the timber surface - essentially performing as a sun screen.

Microporous paint allows the timber to breathe because it’s not oil-based. Your doors can be single colour, dual colour, or varnished. If you do decide to opt for varnished, we recommend that they be re-varnished every two-four years to protect the paint.

Colour-wise, we invite you to select any RAL or Farrow & Ball colour.

The first and most popular option is what we describe as ‘fully finished’. This involves the installation team completing all the internal finishing work that might have been impacted by the installation and undercoating or painting of the internal architrave and sills. It also includes restoring any damaged plasterwork for you to decorate. Any further decorating, such as wallpapering or painting, is left to you so that you can match to your existing decor. Externally, any damage to rendering or pebble dashing will be put right – ready for you to repaint if required.

The second option is called a ‘first fix’. In this case, the installer will fit the door into the opening and finish off the job externally, but leave all internal finishing, such as plastering and installing architrave or tread boards to you, your builder or your preferred decorator.

Factory finishing to the highest technical design and material standards is key to an extended lifespan. Our preferred redwoods include laminated Nordic redwood and Accoya, due to their tried and tested long life expectancy and ability to hold paint well. 

The most popular long-life hardwoods include laminated oak and sapele; these are ideal for staining, varnishing and painting. Should you wish your timber to last longer than a 60-year life span, opt for Accoya. Properly seasoned and laminated hardwood can last a little longer than redwood, and Accoya – which is a specially treated redwood – is one of the world’s longest lasting timbers.

In the last few years, we have seen an emergence of thermally-efficient aluminium which encapsulates the features of slimline deco period steel doors.

There is also a new breed of composite and uPVC heritage doors that look more like timber than timber! They are sympathetic to period properties. Take a look at our gallery of approved agent installations to see for yourself.

As a rule of thumb, uPVC , composite and aluminium alternatives typically cost approximately 30% to 100% less than timber or steel.