Foundations & Basework
These works can be carried out by Westbury or by your own builder. Either way, we will produce detailed drawings and specifications. Before the work starts we will liaise with the local Building Inspector as to whether adverse soil conditions in your area require special provision for deeper or piled foundations.
Walls are built directly up from the foundations. They can be built in either block or brick. Cavity insulation is inserted between the internal and external skins.
We make sure that all materials used match the existing building as closely as possible, i.e. brick colour, bond and type of pointing.
The floor base is built up with 100mm of hardcore, blinded with ballast. 100mm/150mm closed cell polyurethane floor insulation is placed on the hardcore and a 1,200 gauge polythene membrane laid on to this.
A concrete slab 100mm thick, is laid on top with A142 steel reinforcing mesh, which is incorporated into the oversite to prevent movement or cracking. The oversite is then ready to accept a floor screed, which will take the floor finish of your choice.
Drawing of slab construction for underfloor heating.
Joinery
All our conservatories are manufactured using a combination of modern and traditional joinery techniques in our own workshop. The joinery sections will be carefully chosen to achieve the balance of weight. Our aim is to design a building that will enhance your home.
After the timber has been cut, machined and sanded, it will be assembled using double tenons and mortices to ensure stability. All framework is stub-tenoned. Glazing bars can be traditional single glazed lambs tongue, 20mm plant-on, or 42mm to create a more substantial impression.
We pre-assemble all our roofs in our workshops, minimising the time on site. This also allows us to measure and cut the glass before toughening and manufacturing the sealed units. All doors and sashes are also pre-hung and glazed with locks fitted prior to delivery.
Timber
We go to great lengths to make sure our timber is both durable and stable. We have installed humidifiers in our workshop to ensure that the timber maintains the correct moisture content, aiding its stability.
We only buy sustainable timber and only use a small amount of hardwood where elements of the building are very exposed to both sun and rain. Where components are internal, there is no need for hardwood and therefore, redwoods are used.
The rafters are made from clear (knot free) laminated redwood. This makes them stronger and more stable. Doors and sashes need to be extremely stable so that there is no movement or shrinkage in summer and minimum expansion in winter. For these we use clear Douglas fir, a traditional door timber. Framework and head plates are from treated clear redwoods and the king pins, ridge, finials, cills and thresholds are from hardwood. All our timber is of prime grade and free from knots.
Glass
Double glass unit technologies are constantly improving to meet our ever-rising standards to reduce heat energy consumption. The aim is to raise thermal insulation with lower U-values and reduce unwanted solar heat gain in the summer months.
At Westbury we use the latest technology without compromising the traditional depth and quality of the window mouldings. We currently specify 24mm double-glazing units comprising 2 sheets of 4mm toughened safety glass with 16mm cavity.
These are Argon gas filled and use the latest warm-edge spacer tube system to maintain thermal resistance over the whole window pane. This system also reduces the possibility of condensation forming at the edges and has a hard/soft coat low E coating to the internal cavity surface. Together this gives our windows and glass roofs a very low U-Value of 1.4 W/m²°C (lower than 1.8 currently required under part L/B of the Building Regulations).
Where large areas of glass or other circumstances dictate we can offer the option, at extra cost, to use higher insulating products such as Conservaglas or Planitherm Total to obtain U-values as low as 1.1 W/m²°C.
Similarly, we offer the option of a solar reflective coating applied to the inner surface after installation. The materials offered can vary in their performance of reducing ultra violet light penetration (99%) harmful to fabrics and a cause of fading; glare reduction (18-40%); and reduction of heat gain (43-46%). We will advise on selection depending on location of the glass and appearance.
Windows & doors are factory glazed to benefit from the clean and dry environment.
The glazing units are fitted into rebates with our unique drained glazing system, which have totally concealed open outlets. They are bead glazed using the latest glazing tapes and stainless steel fixing pins.
Glass roofs are site glazed. These glazing units have the top sheet extended 80mm at the bottom edge to form a drip to prevent any capillary action and protect the lower spacer bar. Also to ensure water is discharged over upstand flashings in the case of roof lanterns, or into gutters.
Roof glass units are gasket sealed into rebated rafters and held in position by our specially profiled two-part aluminium capping, powder-coated either white or lead-grey colour and fixed with stainless steel screws, ensuring that the roof is both leak and maintenance free.
In cases where single-glazing is still desired, such as Grade I or Grade II* Listed Buildings, the toughened safety glass will be face puttied into rebates with traditional linseed oil putty.
To control quality, reduce transport and support local enterprise, all Westbury glass is sourced from a nearby Essex supplier.
Environmental Policy
We are committed to a continuing policy of efficiency in order to reduce the impact on the environment to the minimum level possible and have implemented the following procedures:
We only use hardwood where absolutely essential. Hardwood is not efficient because it has extremely high wastage. Instead, we use redwood that can be cut and ordered to size so that we only buy what we need. All of the timber used is from sustainable (managed) forests only.
We have opted to buy timber that does not come from rainforests, be it FSC Protected or not. Once again, we are fully committed to give you a durable and stable building and will not compromise on the longevity. We always ensure that our buildings are highly insulated for the future and will not need rebuilding, nor upgrading for the foreseeable future.
The longer a building product lasts, the better it is for the environment. Our roofs, glass and timber provide durable waterproofing that maintains the thermal efficiency of the building for a very long time. Whatever your requirements, Westbury will provide a sustainable solution.
Gutters, Downpipes & Hoppers
Conservatory gutters and cornices should be set level as laying them to fall would leave an unsightly gap between the gutters and the conservatory itself. We use aluminium gutters, coloured to match the joinery.
These will not leak when installed. In addition, they require low maintenance and are sturdy enough to support a ladder when access is required to clean the roof glass. The O’gee and moulded shape of the gutters will also help to enhance the final appearance at the point where the roof joins the headplate. All downpipes discharge into soakaways, or are coupled to existing downpipes.
Ventilation
In order to enjoy the full benefits of your garden room throughout the year, attention to ventilation is essential, especially in a south-facing conservatory, which can become extremely hot when the summer sun reaches its height.
We can recommend, both at the design and construction stages, a variety of ways to ensure that sufficient ventilation is provided. Roof ventilators are the best way in which to release hot air as it travels upwards. These are operated by electronic openers switched manually or automatically by thermostatic controls with rain sensors.
Incorporating double-hung doors on either side of the design allows a through draught. Side-hung casements are an excellent way of drawing fresh air in while at the same time pushing hot air upwards to the roof vents. When open, they give an unrestricted view.
Over the years we have developed a unique stormproof roof vent using powder-coated aluminium flashings. When closed this remains watertight, even in the most adverse weather conditions. These do not leak.
Box Gutters
These are used where a conservatory roof pitches down towards the house, or where the existing wall to the flank or flanks of the conservatory is higher than the gutter level. Using box gutters adds a wide range of options for the roof design, especially where a low first floor window obstructs the conservatory roof.
Our box gutters are lined with lead-grey Flag UK (a seamless single-ply polymeric membrane), ensuring that they are completely sealed and free from leaks. They are supported internally with steel beams, which are clad with timber, and the cavity insulated.
Flat Roofs
The warm roof method is used to prevent any cold spots from forming, which can lead to condensation. Again, Flag UK is used, as it is a far superior product compared with traditional roofing materials, offering a fifteen-year manufacturer’s guarantee, and backed by a BBA certified durability in excess of 25 years.
Box gutters and flat roofs are suitable for access and maintenance, however it should be noted that the edges are unguarded and the surface should not be trafficked when there is snow or ice present as this will be extremely slippery.
Finials & Cresting
A turned ball or spike to the kingpin may be sufficient for the external finishing touch of the roof. Should a more ornate finish be appropriate, we have a selection of crestings and finials, which range from original Victorian patterns to simple contemporary designs.
Fittings
You can choose from a selection of brass, bronze, satin chrome, polished chrome or plain black. Our ironmongery collection ranges from simple, unobtrusive styles to some specially designed handles and fittings. We offer a special range in conjunction with Turnstyle Designs (www.turnstyledesigns.co.uk)
Lead
Code 4/5 lead is used to make the seal between the new conservatory and the existing house. The lead is dressed to achieve a neat and unobtrusive appearance. All flashings and leadwork are carried out according to Lead Association guidelines. This is carried out by us, so we will be responsible for the building being watertight.
Paints
We have carefully selected a range of 24 colours specifically to work with Garden Rooms in a choice of colourways. We recommend acrylic (water-based) paint, which is environmentally friendly. Major paint manufacturers for many years have not recommended the use of oil-based paints externally. This is both durable and easier to dispose of and no chemicals are required for the cleaning of hands, brushes etc.
We will spray two base coats before the conservatory leaves our workshop. One final coat of acrylic paint applied on site with a synthetic brush meets the manufacturer’s specifications. When the time comes to re-paint your conservatory, only one coat will be required.
Planning Permission & Listed Building Consent
Planning Permission is not always needed as you are entitled to extend your house by up to 70 cubic metres (50 cubic metres in a conservation area or on a terraced house) without consent. However, if you have a larger conservatory in mind, or your house is already extended, we may need to seek formal planning consent.
If you live in a conservation area (and the conservatory is to the front elevation), or in a listed building, approval is essential. If listed building consent is granted, your conservatory will be exempt from VAT. As Westbury have vast experience in dealing with local authorities in listed and planning consent, we prefer to make all applications for you.
The planning process has recently changed to nationally rationalise the form of application and also allow it to be submitted electronically. This increases efficiency into the system, but also brings complexity in that the form is now more sophisticated. In addition, it has become a necessary requirement in more cases, for support assessments to be produced, such as floor risk, Heritage statement, design and access, tree survey report, etc. Our Planning Department has mastered the new system.
Insulation
100mm floor insulation is used in the make up of the solid floor to give a calculated overall U-value of 0.2W/m²°C
100mm Rockwool Cavity Batts is used in the brick and block cavity wall construction to give a calculated overall U-value of 0.29 W/m²°C
100mm Celotex insulation is used in conjunction with our warm deck flat roof margins to give a calculated overall U-value of 0.16 W/m²°C
150mm Celotex insulation is used in tiled/slated pitched roofs to give a calculated overall U-value of 0.16 W/m²°C.
Westbury Conservatories Limited operates a policy of continuous improvement and reserves the right to change specifications from time to time. Specifications will vary to meet the specific needs of each project.