Structure Details

Timber frame buildings are one of the most popular methods of construction worldwide. Over 70% of people in the developed world live in timber framed houses, whilst in the USA and Canada it accounts for 90% of single and double storey buildings.  In Scotland, timber frame is the most popular method of construction due to its suitability for cold climates and its inherent high energy efficiency. 

A RUBICON™ Garden Room or Garden Office is constructed from treated timbers to BS5589:1998 giving an expected life span in excess of 30 years.  The Wall frames for our Insulated Garden Buildings are built in factory controlled conditions, from a minimum of 96mm x 47mm C24 & C16 structural grade regulated timber, whilst our roof and floor uses the superior strength C24 grade of timber. This ensures the quality and precision of each component, whilst reducing on-site build time due to the "kit" format of assembly.

To prevent the structural panels from deforming under wind-load and potentially collapsing (known as racking strength), the exterior walls of a RUBICON™ Garden Room or Garden Office are covered (sheathed) in structural grade sheets of Oriented Strand Board (OSB3) a high-quality exterior-rated, wood composite board or plywood. The sheathing also helps to reduce wind penetration through the external walls. This is the same construction method as used by well known Timber Frame House-builders from Scandinavian and Germany such as Scandia-Hus and Huf-Haus.

Likewise, all our buildings are boarded underneath with 9mm Ply or OSB3 to protect against vermin attack. If not protected in this way, vermin can gain access to the insulating foam panels under the base.

To protect the interior timber structure from penetrating rain water, and to allow the building to breathe, a waterproof membrane to BS4016, is applied to the outside face of our Garden Rooms. This waterproof, but vapour permeable layer protects the internal timbers from any water ingress, such as wind driven rain, that may find its way across the cavity between the exterior cladding and the internal timber frame.  At the same time it allows any moisture vapour trapped in the panels to escape - hence allowing the structure of RUBICON™ Garden Room or Garden Office to "breathe" naturally.

To prevent condensation occurring within the internal wall panels (called Interstitial condensation) a vapour barrier to BS5250 is often required between the insulation and the internal plasterboard. If a Vapour Barrier is not fitted then moisture, in the form of vapour, can pass through the plasterboard, through the insulation, and it can then condense on the cold inside face of the outer sheathing, causing mould growth and timber rot. Whilst the risk of this problem is very low in a standard garden room, it is a particular problem where a lot of moisture is generated internally by for example, a shower room.  As standard a RUBICON™ Garden Room or Garden Office comes complete with an internal vapour barrier (membrane) to fully meet NHBC and TRADA specifications. 

Our premium range Garden Rooms and Garden Offices offer 145mm of Kingspan PIR foiled insulation in the Roof, 90mm in the Walls and 80mm in the Floors. Where extra insulation is specified, this is installed as both primary and secondary layers. The primary layer of 90mm sits between the timber frames, whilst the secondary layer of 25-50mm sits across the frames preventing cold-bridging from the warm side of the room to the cold outside. If you are not using the room all year-round then, as an option, we can reduce the insulation and save you cost.

We can offer UPVC, Timber and Aluminium to suit most budgets. White UPVC is the cheapest followed by coloured UPVC, then timber with aluminium the most expensive. As standard our doors and windows are UPVC with grey exteriors and white interiors. They all have multi-point "Secured By Design" locking systems so security is less of an issue, and they are fitted with double glazed, argon filled 'K' glass as standard with warm edge spacers, thereby meeting the latest Building Regulations.

Until relatively recently, standard flooring grade chipboard was the automatic choice for most timber frame buildings. Chipboard is quite durable if it stays dry but if it remains wet or damp for long periods it can swell and lose strength. Moisture resistant chipboard (with better quality glue) is often  specified in houses for areas such as bathrooms and kitchens.  

In a RUBICON™ Garden Room or Garden Office an industrial grade, 22mm moisture resistant T&G composite board is used. This provides good protection during and after construction, even if the boards become wet, whilst also providing an excellent base for tiling, carpet or laminate.

Our standard fit is now Wood Fibre Composite but we offer Western Red Cedar as an extra cost option or treated European Redwood (details HERE) as a no-cost option. Cedar and Composite cladding materials are used extensively in North America, Scandinavia, and Australia, often in extreme weather conditions. The building is manufactured with a ventilated cavity to stop any driving rain or water vapour penetrating the building. This has the same venting effect as the cavity wall in a house between the internal block-work and exterior brick layer.  

A RUBICON™ Garden Room or Garden Office with vertical cladding offers a fully ventilated cavity wall, ensuring full compliance with NHBC and TRADA professional codes of practice.

All our buildings are dry-lined and plaster skimmed to provide a 'house like' interior feel. Skirtings and architraves (where applicable) are provided to complete the quality feel.

All buildings come with a comprehensive package of electrical equipment as standard, with lights and sockets in a choice of chromed, satin or white finish. Sufficient spotlights in the ceiling, plenty of double sockets, twin exterior lights, 2KW electric heater with timer and thermostat, exterior waterproof socket for your lawn-mower and a mains RCD consumer unit all being standard fittings.

If you need interior dividing walls and quality oak doors, or even a shower-room with toilet then we can do it, including all ground works for water and drainage.