Let us first consider the visual aspect. This is a feature of ‘what is seen’ something that the client will have to live with for the majority of the time as large opening doors in the UK are only opened infrequently in summer. If an open aspect is wanted, year-round vision, then a sliding door could possibly offer the best option with less ‘visible’ aluminium in the ‘sightline’ between the inside and the outside. For large sliding doors today, the ‘lift and slide’ is the best option as these doors offer the smoothest and easiest of opening as they lift off their weather seals when open. The only downside is that you will only ever get a part opening, as the opening panel or panels will stack behind each other within the opening. To enable to have a full width clear opening, where a door system is to be fully open, then the sliding folding option should be chosen, allowing all the panels to concertina to one or both sides of the opening.
The next crucial decision for the customer would be the threshold detail. For many customers, wishing the ‘bring the outside inside’, would opt for a flush threshold with the outside of the property. This is often quite a detail to achieve depending on the construction of the property. Not only will the door frame need to be fitted below the inside floor level, often below the DPC line, the outside detail should contain a drainage detail such as a channel draining arrangement to ensure that in heavy weather rainwater is quickly drained from the threshold area. Whilst sliding and folding doors can be provided with a flush threshold detail, a better weather rating will normally be obtained with a lift and slide door where the weight of the door in the closed position effectively seals the door to the threshold.
Moving a little further into the design and structure of the building when choosing a door, the structure of the head of the opening should be considered carefully. Deflection in the structure, particularly on large openings, will have a detrimental effect on the operation of the door. If the opening in the property has been in place for some time, any settlement of the structure should have already taken place, which will allow the surveyor to cater for the head deflection in the final size of the door to be made. With a new installation, settlement can take place over a period of time and it is worthwhile to allow for this potential settlement in the door size and the fixings at the head of the door. On any wide door, and in particular sliding folding doors, any deflection at the head of the door can cause issues with the operation of the door, so with some adjustment built in that can be accessed during a maintenance visit will ensure that doors can easily be maintained for many years.
Given the customer choices, the property survey needs to be carefully undertaken with someone who understands building structures and importantly the requirements of the door chosen to be installed. The need to understand the threshold detail and the structure above the door and the reveals should also be carefully considered. Older properties will have a brick or block cavity closure with a vertical DPC, even older properties will likely have solid walls. In order to minimise cold bridging, it may be necessary to incorporate a thermal cavity closer or alternative method of insulation to the reveal. Of course, buildings are built of other materials as well as brick, so the surveyor needs to know what to look for and what can be fixed to.
Regular yearly maintenance of doors is something that should be considered. As many doors are built to last, the cleaning, lubrication and adjustment will ensure not only an extended service life but also continued ease of use.
Aluprof offer a very wide range of products and within each of the product ranges options exist to change profile sizes and frame conditions to meet customers’ expectations. Using the same high-quality systems specified by architects, Aluprof’s products are now widely use on homeowners ‘grand designs’. With extensive growth across Europe spreading into the Middle East and with firm roots already in the East of the USA, the company is becoming a global player in new build and home improvement supply. Further information is available on the company’s website at aluprof.co.uk or direct from their UK office in Altrincham on 0161 941 4005.