Environmental
The structure - Timber is a renewable resource, and is used in it's raw state, without industrial processes altering it, its inherent natural beauty will last. An oak frame will last hundreds of years and hence outlive the time the oak has taken to grow. By using our native oak we are encouraging it's replanting because of the increased demand. Softwood timber-frames (Douglas Fir) similarly outlive the time the tree has taken to grow. Compared with other building components timber scores very highly due to the minimal embodied energy in preparing the material for use in construction.
The Enclosure and building performance
We strongly favour carrying the environmental considerations though all aspects of construction, through to the life cycle of the building; such as efficient thermal performance;waste management and energy transfe
Structural Frame
We believe in exposing as much of the timber to view as possible and thereby enhancing the spatial quality of the rooms. Incorporating full-height volumes into the design will give an impressive airy quality.
The frames are traditionally jointed using the mortise and tenon joint, which is draw-pegged with tapered oak pegs. The structure is integrally braced with curved oak bends, jointed into the frame.
Foundations
The frames can sit on a variety of foundation and ground floor bases, bearing in mind that there are point loads at the base of each main post. On sloping sites the post can continue to ground level creating a 'building on stilts'.
Building Length
The timber-frame building consists of one or more bays. A bay length is typically between 2.2m and 4.2m (7ft to 14ft) and will be designed to fit a plan layout. A medium sized house will typically consist of three or four bays.
Building width
The width of a simple cross-frame will be between 3m and 6.5 m. Lean to's, on the side of the building, or the 'Aisle Barn' design will add width to the plan if desired.
Wall cladding
A variety of cladding is suitable for a tirnber-frame, and dependent on planning considerations, choice and cost. Your timber-frame will always be visible to the interior; there is a choice as to whether the frame is exposed to the exterior; as was done traditionally with oak framed houses; although barns were traditionally clad all over.
Externally exposed frame and infill panels
The traditional lime rendered oak laths as infill, or brick. This method is aesthetically very pleasing although has a higher maintenance initially, re-liming the frame joints and panel interfaces annually for the first few years of seasoning.
The modern approach to exposing the frame externally utilises innovation in foam sealing tapes which expand to fill a gap. Frame joints and panel interfaces are taped before assembly. As the frame seasons the tapes expand to fill the shrinkage gap. The traditional appearance is created with low - maintenance.
Completely clad exterior
More frames are finished off in this way now mainly because of the increased thermal performance and weather barrier of not exposing the structural frame to the elements. Cladding is responsive to planning considerations and can be timber boarding(vertical or horizontal), slate or tile hanging or masonry walls. Large areas of glazing will allow the frame to be seen from the outside through the windows, and will fill the interior with natural light and solar gain.
Insulation
Superior insulation can be given to a timber-frame whether as infill between the main frame or externally to the frame.
Warmcell (recycled newspaper) is the most ecological, although mineral wool, foam panels, and sheeps wool are alternatives.
Structural insulated panels (S.I.P.) are the most recent innovation and are a sandwich panel of plasterboard, foam core insulation, and OSB timber panel, pressure glued into a single unit. They only require external cladding as a finish.
Roofing
Steeper roof pitches will give the building more presence and enable a 1.5 storey house to have a spacious first floor. Roof finishes will be determined by planning considerations and can be Tile, Slate, Thatch and Shingle.
Fabrication and erection
Our timber-frames are constructed off-site at our yard in Somerset. Typically a house will take about 2 months to fabricate; setting out individual frames, scribing and jointing before being dismantled, labelled and stored. A small team of experienced carpenters will work on each house and bring pride in the craft to each frame.
The frame pieces are taken to site by lorry and erected normally within a week. Access to the site for lorry and crane should be available; as should the prepared foundations and base, prior to erection.
After the frame goes up
Once the frame has been erected the work of Green Oak Structures is normally over, and other building contractors will finish your building (cladding, roofing, plumbing, etc.). We recommend that the frame is cleaned by a professional blast cleaning service; this will remove the metallic black stains from the saw mill, and any other marks/dirt gathered over construction. It also softens the hard edges of the oak. Over the course of several years the frame will season and dry. In this process shrink splits and shakes will develop, as will some gaps at the shoulders of joints. This is normal, adds to the character of a timber-frame, and does not affect the stability of the frame. We will be happy to return to make periodic checks on your house frame.
