Conservatory Aluminium Frames
Aluminium conservatory window and door frames are less common in the home improvement market where plastic dominates. In the 1970’s and early 1980’s it was recognised as a strong, durable and quality product but somehow lost its way ? something to do with the fact that the window frames were often in fact sub-frames surrounded by hardwood and looked a little incongruous even then. Later, when powder-coated aluminium that looked like PVC-u came in, it felt cold to the touch and suffered from surface condensation.

Aluminium conservatory framing has been developed a bit since those days and most commercial buildings- shops, restaurants, offices etc. ? which have high insulation standards to meet are fitted with them.

Aluminium only ever comes in two finishes ? anodised and polyester powder-coated. Anodising is an electro-chemical process that creates a tough oxide finish, physically altering the surface of the metal and accidentally giving it a high resistance to electric current. Anodised aluminium door handles that you see in commercial buildings may be your only experience of this finish in its SAA (satin anodised aluminium) finish form. Dyes can be added to the process when the metal is porous so colourful frames can be created that look nothing like cheap ironmongery.

Polyester powder coatings spray-applied in the factory offer a perfect smooth finish that is consistent in both colour and texture. It also offers excellent resistance to ultraviolet light (something which plastic doesn’t generally excel at) and if it gets scratched it can be repaired in situ (again something that plastic can’t excel at).

Conservatory Timber Frames
Not so very long ago all windows were wood. Even apprentices with builders in the 1980’s used standard-sized softwood timber conservatory windows and doors on all new developments. Painting had grown out of fashion then and timber parts weren’t primed in the factory ready to be undercoated and glossed as they had been before. Instead they came off the lorry base decorated with a light stain and were top-coated with stain on site. Painting in the site store shed trying to avoid running or collecting paintbrush hairs was all part of the fun! The joinery companies (they still exist) had catalogues full of standard off-the-shelf models in different styles. But plastic was just around the corner.

Timber conservatory windows still exist but their market share has been reduced a fair bit since then ? all of which may change because timber has its own advantages. It can even be coated with a white polyurethane finish to make it look like the other PVC-u windows in your home. Here you get the solid strength, insulation and environmental soundness of wood without that maintenance problem we call painting.

Whichever timber you use, you can make sure it comes from a managed and sustainable source by looking for the FSC (Forest Stewardship Council) label. This isn’t the world’s only system of reducing deforestation but it is the most high profile.

At the bottom end of the timber market comes softwood pine, usually from Scandinavia or Canada, where it grows slowly in cold climates to produce timber of close grain and high strength. All pine used in construction comes from these areas, even the stuff used for garden sheds.

Where timber takes over from other materials is in the detail. As it is a very easily worked material, fine sections can be carved that remain comparatively strong. Glazing beads can be cut in windows that exactly match the originals and in period homes these originals can be quite slender. It doesn’t necessarily mean you’re forced to have single-glazing either because the bars can be superficially planted on today’s 24 or 26mm thick sealed units. Seeing the window square on you won’t notice a difference but if you can reduce the depth of the unit to 18mm it will help when you look at an angle. 20mm clear glass sealed units were standard in the 1990’s made up of two 4mm panes beside a 12mm cavity: a decade earlier the cavities were down to 8 and even 6mm. The growth in the thickness of double-glazed windows’ air gaps is down to ever increasing standards for thermal insulation over this period and until the advent of low-emissivity coatings and argon gas fillings, making it thicker was all that could be done to improve it.

Finished with a Georgian-style gable end, a timber-framed conservatory painted white with a single-glazed roof is in a league of its own. The appearance is excellent and structures like this are easily designed 6 or 7mm wide and 11 or 12mm long. If you can run to the expense of including a full cartwheel framed light or semi-circular ?sunburst? window in the gable, it becomes even more impressive ? in this form your glass extension becomes a classic piece of architecture, a mile away from the bolt-on plastic box model.

The range of hardwoods used for framing is necessarily restricted to ensure that only wood sourced from sustainable forests is used. Most hardwoods are tropical, from either West Africa or Indonesia and particularly in the case of the latter, the rate at which tropical forests are disappearing is alarming and is terminal for many species.

Idigbo is a West African species of high strength wood that has a high natural resistance to fungal attack and rot: you don’t get to evolve in the humid tropical forests of the Ivory Coast without having some genetic preservation built in. The relationship between stress and strain in any given section is measured by the ?E? value ? the higher the value the stronger the timber. With a timber of higher strength you can use a smaller section of frame and mullions to suit an Edwardian fenestration style for example.

Conservatory Oak Frames and Barn styles

Extending onto a converted barn or similarly styled home may lead you towards an oak-framed conservatory or sun room. Oak and glass go very well together at least aesthetically. Using oversized chunky framing between the windows and a generous sole and head plate above and below them a roof of any material can be supported. Green oak is surprisingly soft and workable and regularised sections can be carved with stop chamfers and subtle details. With an oak frame you’ll want to enjoy the conservatory from both inside and outside and this wood is best finished with some gentle beeswaxing to bring out the beautiful grain and colour.

There are really only two choices for any dwarf walls with an oak frame, the first being none at all, sitting the sole plate directly on to the damp-proof course (DPC) for a fully glazed wall design. This could well be the most suitable but it’s important to make sure that you have at least two courses of bricks beneath the DPC at ground level. This 150mm will ensure that rain splashing doesn’t soak the sole plate on a regular basis thus shortening its life expectancy.

The second choice is to have a short dwarf wall of perhaps just three or four courses of bricks above the DPC; however it doesn’t work well to have high brick walls with a squat oak frame sitting on them ? the proportions and beauty of oak dictate that it should be by far the most prominent material after the glass.

Extending any converted barn presents a design challenge in trying to maintain the agricultural look but it is possible. The main rules are to try to maintain the scale and grandeur of the existing structure in the individual elements of your addition regardless of its size ? in other words if you have planning permission only for a small addition don’t scale down the detailing in empathy but keep it in sync with the original.

Look to using handmade second hand roof tiles and bricks that blend in with the existing ones and resist the urge to create too much hard landscaping outside if it isn’t there already. Most barn additions blend in better with green landscaping rather than with decks or patios.

If your barn home has a curvaceous plain tiled roof, trying to tie in a die-straight glass one to it is always going to be a problem. It is far better to intersect the two roofs with the same material and if you still want a glazed roof on your new room switch to glass at the plane of the wall line or beyond. Cross tie beams that restrain your wall plates can be an architectural feature whether you need them or not in this timber and you may even want to install knee braces at the post and tie beam junctions to replicate barn aisle details.

There are specialist companies who design and build in oak using traditional methods of jointing without metal fixings. Admittedly they tend to specialise in new homes or detached outbuildings (barn-style garages for instance) but they will have the expertise you’ll be looking for that other builders and carpenters won’t.