Combining roof windows - how to light the loft well?
A single window in the attic is often not enough to evenly light the entire room. For this reason, a commonly used and very effective solution is combining several roof windows into sets (combinations). Such a construction not only provides an optimum flow of natural light, but also opens up the space, giving the interior a modern, bright character.
Read when it is worth deciding on a larger number of glazings, how many windows can be joined together and what installation rules you need to bear in mind!
One large or several smaller roof windows?
Installing several smaller windows in the roof is a much better way to optimise light in the attic than installing a single, very large window.
Why install roof windows next to each other?
Better distribution of light: Several windows installed at intervals or in sets of twins allow sunlight to reach every nook and cranny of the room.
Healthy energy balance: The correct positioning of the joinery has a positive effect on proper air circulation (ventilation) and the energy balance of the entire building.
** Compliance with standards:** It is worth remembering that the total window area in rooms intended for permanent human habitation should be about 10-12% (1/8) of the floor area.
Combining roof windows into sets - basic installation principles
The correct installation of several windows joined together is crucial for their airtightness and proper functioning for years. When deciding on combinations, the following roofing rules should be strictly observed:
** Roof pitch:** Roof window combinations can be carried out on roofs with a pitch of from 15° to 90°.
** Frame compatibility:** It is only possible to combine models which have the same frame thickness.
Horizontal jointing (side-by-side): The windows must have an identical height. However, their width may vary, allowing for interesting asymmetrical arrangements.
Vertical jointing (one on top of the other): The principle is reversed - the windows must be of identical width, but their length can be varied.
** Consistency of material:** In combinations, windows made of the same material should be joined together (timber with timber, and PVC with PVC models).
Dedicated flashings: In order to properly join windows, it is necessary to use systemic composite flashings (the so-called combi flashings from OKPOL's range). They are responsible for a tight connection of the joinery with the roofing and safe draining of rainwater from the roof slope.
Are you planning external blinds? Remember about spacing!
The desire to install external accessories (such as heat and noise protection roller shutters) must be decided even before the windows are installed. If roller shutters are in the plans, the spacing between windows joined vertically (one above the other) must be a minimum of 25 centimetres in order for the roller shutter cassettes to fit and operate freely.
When do I need the help of a builder?
Larger glazings - especially extensive horizontal joints - are worth consulting with an architect or builder regarding the use of additional roof reinforcements (so-called replacements). It should be borne in mind categorically that cutting rafters yourself by inexperienced people may damage or weaken the roof's load-bearing structure. This work should always be entrusted to specialist roofing teams.