GB2529197B

GB2529197B - Loft flooring system

Info

Publication number: GB2529197B
Application number: GB1414315.0A
Authority: GB
Inventors: St John Spencer Galliard Cave Piers; Andrew Godfrey Paul; John Lennan David
Original assignee: Nominal Sum Ltd
Current assignee: Nominal Sum Ltd
Priority date: 2014-08-12
Filing date: 2014-08-12
Publication date: 2019-06-26
Anticipated expiration: 2034-08-12
Also published as: GB2529197A; GB201414315D0

Description

Loft Flooring System

Field of the Invention

The present invention concerns improvements in and relating to loft flooring systems that are adapted to preserve the recommended depth of loft insulation material in the loft when laying the flooring.

Background to the Invention

Energy efficiency of buildings is a pressing issue that now affects us all. There is increasingly widespread appreciation of the need for better building insulation to combat thermal energy wastage and its associated costs to the environment as well as the direct cost to the property owner or tenant. Alongside cavity wall insulation, loft insulation is the major target for improvement in many homes and a key feature or recommendation point in the now statutory energy efficiency survey that accompanies all residential property transactions in the UK. UK government and building industry recommendations are for a 270-300mm depth of insulation material to be laid in the loft/ attic between the joists of the loft/ attic floor to reduce loss of inexorably rising internal heat into the loft space and out through the roof. Indeed, Part L of the current UK Building Regulations requires a depth of at least 250mm. Since most joists (also known as ceiling ties) are 75mm or 100mm deep, in general the insulation will need to rise 200mm or more above the top of the joists and thus any flooring subsequently laid over the joists will generally compact the insulation back down by that difference in depth. Such compaction greatly reduces the effectiveness of the insulation, which relies on being un-compacted in order to trap air in pockets and thus should be avoided.

In the case of installing permanent loft flooring in the manner of a loft conversion, turning the loft into proper living space, the issue is normally avoided/ addressed by transferring the insulation capability from the floor to the rafters of the roof instead. However, for the more temporary loft flooring that is often installed by home-owners themselves to serve as a platform for storage of belongings in the loft there will generally not be an obligation or desire to expensively line the roof in place of the loft floor.

The compaction of the loft floor insulation is generally ignored until flagged up in a subsequent energy efficiency survey carried out prior to sale of the property. However, this is of course, very energy wasteful and the problem has inspired some consideration in the industry. A primary proposal for addressing the problem is to lay an array of mutually parallel boards/ battens edge-on on top of the joists running orthogonal to the joists and to be nailed down to the joists to provide a raised floor with the insulation filled firstly between the joists and then between the battens. This system is time-consuming to install and, if needed, also time-consuming to uninstall and the upper part of the insulation either needs to be laid separately or be locally crushed where the battens run. A further proposal to address the compaction problem is outlined in GB 2438620A (Milner) and entails provision of box beam spacers that are again laid on top of the joists running orthogonal to the joists and to be nailed down with blocks to the joists. With this latter system the box beam spacers are specially constructed having a rectangular box form with opposing sidewalls and top and bottom walls and to achieve the required insulation depth using the system the insulation material must be inserted into the rectangular box form. This system lacks versatility and although it is somewhat less time-consuming to install than the other prior systems it is rendered awkward by the need to fill the insulation firstly between the joists and then into the spacers and between the spacers rather than simply laying it between the joists.

To address these problems of the prior art the present applicants have previously developed a system of loft flooring that comprises a plurality of bridging supports each adapted to provide an elevated bridge above joists of a loft floor and which span above the joists, running transverse to the joists to protect the insulation laid between the joists from compaction. This system is described in the present applicants’ UK patents GB 2,477,161B and GB 2,477,619B and is optimal for most lofts. However, there are some instances when it is not so suitable and in particular where the loft is part-boarded or fully boarded already and the home-owner does not wish to remove the existing boarding to accommodate the raised flooring system. Removing existing boarding can be difficult and time-consuming and a waste of prior investment. In such cases installing a secondary raised floor above the boarding and laying insulation between the boarding and raised flooring is potentially viable but there is a difficulty in doing so. To place bridging supports or pedestals onto the existing boarding is risky since the underlying joists are hidden and it is difficult to know where the joists underlie the boarding. Misplacing the supports/ pedestals to between the joists can lead to potentially catastrophic weakening of the flooring system there and should be avoided. An alternative solution is required that is safe and reliable. It preferably is also compatible with construction and componentry of the applicants’ existing system to facilitate some inter-changeability and allowing the systems to be used alongside each other if desired.

It is a general object of the present invention to provide a new system and method for laying a loft floor to address the problem of insulation compaction and which is comparatively straightforward and efficient to install and, where needed, uninstall and which addresses the problems of already fully or part-boarded lofts.

Summary of the Invention

According to a first aspect of the present invention there is provided a loft flooring system that comprises: a plurality of bridging supports each adapted to provide an elevated bridge above joists of a loft floor and having a first upright leg with a head and a foot and having, in use, a second upright leg with a head and a foot and a spanning rail or beam therebetween to extend substantially parallel to the axes of the joists and over which flooring boards or flooring panels are laid; and a pair of footsupporting rails or beams one of which supports the foot of the first leg and the other of which supports the foot of the second leg, the foot supporting rails or beams lying above the joists transverse to the joists to span between the joists. The rails or beams preferably are of steel or similar and particularly preferably are formed as rigid rails having a longitudinal channel therealong.

This system can be mounted on an already partially or fully boarded loft floor without needing the existing boarding to be removed or the precise locations of the underlying joists to be determined. The system is able to support the raised loft flooring at a spacing above the joists that is sufficient to accommodate the correct depth of loft insulation material substantially without compaction. The foot-supporting beams/ rails transfer loadings down onto the joists wherever they underlie the existing boarding.

With the system of the present invention installed the flooring boards of the raised floor may then be laid onto the spanning rails or beams and fixed in place. The flooring boards of the raised floor can be screwed to the spanning rails or beams.

Particularly preferably in each leg the head and foot extend substantially mutually orthogonally in parallel planes. A further problem that may plague installation of raised flooring onto existing boarding is the locating of services such as pipes and cabling below the existing flooring and risk of penetrating those services if through screws are driven through the boarding to secure the system. To avoid the risk of penetrating such services the installer is faced with the unsatisfactory option of only lightly securing the system in place but then compromising stability of the system.

In the present invention by having the head and foot extending mutually orthogonally in parallel planes and advantageously further having strut members on the leg supporting the head from the leg in two opposing directions of a first substantially horizontal axis (the axis transverse to the joists) and strut members on the leg supporting the leg from the foot in two opposing directions of a second substantially horizontal axis (the axis parallel to or along the joists) the system is inherently stable and does not need to be securely screwed/ fixed to the existing boarded floor. It is inherently stable and thus may be lightly screwed to just hold it in place but not screwed hard down by long screws through the boarding.

Each strut member is preferably a fin or rib that extends between the head or foot, as the case may be, and the leg. Preferably the strut member spans the angle between the head or foot, as the case may be, and the leg and preferably is triangular in shape.

Particularly preferably in each leg the head is adapted to slidingly engage with the spanning rail. Particularly preferably in each leg the foot is adapted to slidingly engage with a said foot-supporting rail. Particularly preferably the foot supporting rails and the spanning rail are interchangeably mountable to the head and foot. Indeed the foot supporting rails and the spanning rail may be substantially the same in shape and form, even being identical, whereby the system may be assembled from a set of rails that are all formed in the same extruder/press or other manufacturing machine. Preferably the head and foot of each leg are of substantially the same shape and form as each other, yet in substantially mutually orthogonal planes.

Preferably the head and/ or foot is/are each formed as an elongate beam. Each beam is of a maximum width and thickness dimensioned to securely slidingly engage with a corresponding rail.

The described system assembled from legs and foot-supporting rails in rows traversing the joists and with spanning rails lengthwise of or parallel to the joists is quick to install and secure and allows the system to be installed atop existing partial boarding of a loft in a stable arrangement and without risking safety.

In a preferred embodiment the spanning beam or rail and/ or footsupporting beam or rail has sliding engagement means for sliding interengagement with complementary sliding engagement means on the head of each of the first leg and second leg. Preferably the sliding engagement means comprises a flange and which preferably is provided along at least one longitudinal edge (suitably both longitudinal edges) of the spanning beam or rail, while the complementary sliding engagement means comprises a corresponding shoulder of each of the first leg and second leg at/ near the head thereof. This sliding inter-engagement arrangement provides even greater security to the system and also assists good alignment of the legs.

Preferably the spanning beam or rail sits onto the beam of the head of each leg and may be adjusted in span simply by adjusting the extent of overlap of one end, or each end, of the spanning beam or rail on the respective beam of the head. Suitably the spanning element has at at least one end an aperture for a nail or other fixing therethrough for the end to be fixed in place to the beam of the head of the leg. To allow for adjustment, one or each end of the spanning beam or rail preferably has an elongate slot or series of apertures for a nail or other fixing therethrough. Apertures are suitably also provided in the spanning beam or rail to receive screws by means of which the flooring boards/ panels are secured to the system.

Preferably the spanning beam or rail and/ or the foot-supporting beam or rail is cold roll formed but may also suitably be cast or extruded from a metal or alloy (preferably steel) as a channel profiled form. Particularly preferably the spanning beam or rail has a U-shaped profile and mounts inverted onto the head of each of the first and second legs. Particularly preferably the foot-supporting beam or rail has a U-shaped profile and mounts receiving the foot of a first or second leg therein.

The system suitably further comprises a plurality of panels of particle board/ chipboard or fibre-board to overlie the bridging supports above the beams to define the loft flooring. A support assembly of any desired area can be produced by adding further bridging supports to the last bridging support so as to span as much as desired of the length of the joists and using any desired length and number of foot supporting rails or beams or extending them where needed. The first foot of the first bridging support of each row of bridging supports fits into the channel of a first foot-supporting rail, while the second foot of the first bridging support of each row of bridging supports fits into the channel of a second foot-supporting rail parallel to the first such rail and so on. The bridging supports thus-assembled provides a skeletal platform for laying flooring panels on the bridging supports. The bridging supports may all be the same. Alternatively, the bridging supports may include an end support for mounting at one end of a row and main supports for connecting a first said main support to the end support and thereafter connecting a second main support to the first main support and so on until the desired length of support assembly is produced.

Brief Description of the Drawings

Embodiments of the present invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first embodiment of the bridging support of the system from a first end shown in situ mounted with the footsupporting rails spanning several loft floor joists, the flooring support system being based on a set of individual legs that when paired up and used with a spanning rail lengthwise of the joists function as a bridging support in use;

Figure 2 is a perspective view of a variant of the arrangement of Figure 1, in which each leg is braced to a next adjacent leg lengthwise of the joist and to a next adjacent leg transverse to the joists;

Figure 3 illustrates the components of each bridging support, prior to assembly and comprising an upstanding support leg that has a head at the top of the leg to slidingly couple into and support the spanning rail and a foot at the bottom of the leg to slidingly couple into and support the leg from the foot-supporting rail;

Figure 4 corresponds to Figure 3 and shows the first support leg slidingly assembled into the foot-supporting rail and the head of the leg slidingly assembled into the spanning rail.

Description of the Preferred Embodiments

Referring firstly to Figure 1, the flooring system comprises a plurality of bridging supports 1 suitable to carry floor boarding above pre-boarded loft flooring B. The bridging supports 1 are mounted in rows extending lengthwise of the joists J1,J2, J3, J4 of the loft floor or parallel to them. The bridging supports 1 are carried on steel supporting rails 2 that lie on the joists J1- J4 transverse to the joists and spanning them. Accordingly they do not need to directly over-lie the joists J1- J4.

Each bridging support 1 is adapted to provide an elevated bridge above the loft floor at a height above the joists that allows for a suitable depth of loft insulation material to be laid there-under. The bridging supports 1 comprise independent first 1a and second 1b upright legs, suitably moulded of nylon, interconnected in a grid by the steel supporting rails 2a, 2b that bear them and by the steel spanning rails 1c that span between the legs 1a, 1b. The assembled grid is a skeletal platform frame-work onto the top of which the raised floor boarding panels F may be mounted and screwed down onto the spanning rails 1c. The panels F are suitably panels of particle board/ chipboard or fibre-board that overlie the bridging supports 1 to define the loft flooring.

Referring to Figure 3, each upright leg 1a, 1b has a vertical stem with a head H1 at its top and a foot F1 at its base. The head H1 and foot F1 are suitably unitary moulded with the leg and each of the head H1 and foot F1 is formed as a respective elongate beam orthogonal to the stem and with a defined width and thickness to co-operatively engage with a channel of a corresponding rail 1c or 2. The head H1 engages in a longitudinal channel of a spanning rail 1c while the foot F1 engages in a longitudinal channel of a foot supporting rail 2.

In shape and form the head H1 and foot F1 may be identical to each other. Furthermore the foot supporting rail 2 and the spanning rail 1c may be identical to each other in shape and form and may drawn from a common stock and simply differentiated by function, thereby rationalizing on manufacturing and supply costs. Each of the spanning rails 1c and foot supporting rails 2 is cold-rolled formed from steel having a channel section/ profile that is substantially U-shaped and with the rims of the channel being in-turned/ provided with laterally inwardly projecting flanges FL1. The flanges FL1 are designed to embrace the head H1 or foot F1, detaining the head H1 or foot F1 within the channel whereby the head H1 or foot F1 is slidingly movable along the channel but can only mount or de mount by sliding to the end of the channel, ie to the end of the rail. By this means the legs can be positioned where desired to form the platform grid for the floor panels F and held in a stable relationship.

The head H1 is supported from the leg/ leg’s stem by a triangular rib/ fin shaped strut 4 in the angle between the leg/ leg’s stem and the head H1. Similarly the leg/ leg’s stem is supported from the foot F1 by a triangular rib/ fin shaped strut 5 in the angle between the leg/ leg’s stem and the foot F1. The head H1 lies substantially within a first vertical plane that in use corresponds to being co-planar with or plane parallel to one of the joists J1-4 while the foot F1 is in a vertical plane orthogonal to that and which corresponds to being transverse/ orthogonal to the joists.

This system is shown in Figures 1 and 2 as being mounted on an already partially boarded loft floor.. The system is able to support the raised loft flooring at a spacing above the joists that is sufficient to accommodate the correct depth of loft insulation material substantially without compaction. The foot-supporting beams/ rails transfer loadings down onto the joists wherever they underlie the existing boarding.

In Figure 2 the system has added cross braces between the legs both in the direction longitudinally of the joists and orthogonally to the joists for even further heightened strength and stability if desired, although for most purposes this should not be necessary.

In the present invention by having the head and foot in mutually orthogonal planes and the strut members on the leg supporting the head from the leg in two opposing directions of a first substantially horizontal axis (the axis transverse to the joists) and strut members on the leg supporting the leg from the foot in two opposing directions of a second substantially horizontal axis (the axis parallel to or along the joists) the system is inherently stable and does not need to be securely screwed/ fixed to the existing boarded floor. It is inherently stable and thus may be lightly screwed to just hold it in place but not screwed hard down by long screws through the boarding. A support assembly of any desired area can be produced by adding further bridging supports to the last bridging support so as to span as much as desired of the length of the joists and using any desired length and number of foot supporting rails or beams or extending them where needed. The first foot of the first bridging support of each row of bridging supports fits into the channel of a first foot-supporting rail, while the second foot of the first bridging support of each row of bridging supports fits into the channel of a second foot-supporting rail parallel to the first such rail and so on. The bridging supports thus-assembled provides a skeletal platform for laying flooring panels on the bridging supports. The bridging supports may all be the same. Alternatively, the bridging supports may include an end support for mounting at one end of a row and main supports for connecting a first said main support to the end support and thereafter connecting a second main support to the first main support and so on until the desired length of support assembly is produced.

The legs 1a, 1b may be formed as a plastics moulding of nylon, polypropylene, HDPE or other strong plastics, optionally reinforced with fiberglass, steel or other reinforcing material with the assembled and installed bridging support 1 formed from those legs being strong enough to bear double the weight of a 70 kg individual standing upon it.

For most houses constructed in the UK from the 1960s onwards the roof structure incorporates trusses and in such trussed roofs the loft joists’ central axes are normally 600mm apart. The span of the bridging support 1 for such lofts should conform to that and thus be approximately 600mm too or be a multiple of 600mm where it spans over two or more inter-joist channels.

The flooring boards or panels F of chipboard, fibre-board or other suitable flooring material are laid on top of the bridging supports 1 on the platform of the spanning rail 2 and each extend over to the spanning element 2 of the next parallel row of bridging supports 1.

The height of the bridging support 1 is selected to match the required extra height of the floor above the joists J1, J2 to allow the required depth of insulation to be un-compacted. Thus for the case where the joists are 80mm deep and the required depth of insulation is 250mm the height of the bridging support is the extra 170mm or so. For this and other embodiments the required insulation depth is likely to be between 250mm and 400mm and thus the height of the bridging support above the joists would only rarely need to exceed 350mm.

The loft insulation material used may be of any suitable type whether currently known and commonplace or yet to be brought to market including, for example, glass fibre, foil-backed felt, rock fibre or mineral fibre blanket insulation - all of which are available in roll-form. These rolls fit snugly between the joists and are the most common type of insulation, being generally sold in 75mm and 100mm thicknesses and 300mm to 1200mm width, with lengths that range from 5m to 9.4m. Loose materials such as cork granules, exfoliated vermiculite, mineral wool or cellulose fibre are other available forms that could be used but are potentially very untidy and much less desirable. The most suitable form of insulation is roll-form and dimensioned to fit snugly between the joists up to the required 250mm or 300mm depth.

The spanning element is a rigid, strong beam of a metal or metal alloy such as steel or similar that has a channel-shaped profile which both strengthens the beam and facilitates its mounting atop the legs 1a, 1b. The channel of the spanning rail/ beam 2 faces downwardly in use and its side walls constrain the spanning element 2 in place on the legs 1a, 1b against any movement in the direction transverse to the joists J1, J2. The strength of this channel-shaped spanning element/ beam 2 is such that it may meet the floor strength criteria of being able to support approximately double the weight of a 90 kg individual standing upon it.

At each end of the spanning rail 1c there is a pair of elongate slot fixing apertures in the top, in use, support wali of the spanning rail 1c. These fixing apertures allow a nail or other fixing to be driven therethrough into the underlying supporting leg top/ platform to fix the spanning element 1c in position. The slotted and plural nature of these fixing apertures gives the installer a useful degree of flexibility in the positioning of the spanning rail 1c end on the leg 1a, 1b. This positional adjustability is further enhanced by the elongate bi-directionai extending configuration of the leg top/ platform.

In the example installation of Figure 1 five rows of bridging supports 1 are shown, each row having a first bridging support 1 comprising two support legs 1a, 1b joined together by a spanning rail I beam 1c and the second support leg 1b extending to form a second bridging support 1 by being joined to a third leg. For the average loft there will be of the order of a dozen or more joists and, of course, the process of assembly and installation of the bridging supports making up the rows along all of the joists will follow this simple assembly pattern but be repeated as necessary. The steps for assembly are quick to execute and the array of parallel rows covering the loft floor area can be completed in little time and at modest cost.

In a variant of the construction of the spanning rail 1c or foot supporting rail 2, instead of being of steel only construction it may be formed as a composite of a steel skeleton with a plastics moulded case or upper panel that suitably clips, slides or otherwise fastens onto the steel skeleton to provide a medium into which fixings such as screws or nails may be driven to secure the overlying boards/panels F of the flooring or to the existing flooring B. Forming the spanning element with a sturdy skeleton manufactured from pressed steel (suitably in one piece) reduces cost to manufacture and because the steel is not the fixing medium it can be thicker and stronger than when the steel of the spanning element is the fixing medium.

The invention is not limited to the embodiments above-described and features of any of the embodiments may be employed separately or in combination with features of the same or a different embodiment and all combinations of features to produce a loft flooring system within the scope of the invention.

Claims

1. A loft flooring system that comprises: plurality of bridging supports each adapted to provide an elevated bridge above, but not necessarily over-lying, joists of a loft floor and having a first upright leg with a head and a foot and having, in use, a second upright leg with a head and a foot, and a spanning rail or beam therebetween to extend substantially parallel to the axes of the joists and over which flooring boards or flooring panels are laid; and a pair of foot-supporting rails or beams one of which supports the foot of the first leg and the other of which supports the foot of the second leg, the foot supporting rails or beams lying above the joists transverse to the joists to span between the joists.

2. A loft flooring system as claimed in claim 1, wherein in each leg the head and foot are in substantially orthogonally to each other in parallel planes.

3. A loft flooring system as claimed in claim 1 or 2, wherein strut members are provided on the leg supporting the head from the leg in two opposing directions of a first substantially horizontal axis.

4. A loft flooring system as claimed in claim 3, wherein strut members are provided on the leg supporting the leg from the foot in two opposing directions of a second substantially horizontal axis orthogonal to the first substantially horizontal axis.

5. A loft flooring system as claimed in claim 3 or 4, wherein each strut member is a fin or rib that extends between the head or foot, as the case may be, and the leg.

6. A loft flooring system as claimed in any preceding claim, wherein in each leg the head is adapted to slidingly engage with the spanning rail.

7. A loft flooring system as claimed in any preceding claim, wherein in each leg the foot is adapted to slidingly engage with a said foot-supporting rail.

8. A loft flooring system as claimed in any preceding claim, wherein the foot supporting rails and the spanning rail are inter-changeably mountable to the head and foot.

9. A loft flooring system as claimed in any preceding claim, wherein the foot supporting rails and the spanning rail are of the same shape and form, whereby the system may be assembled from a set of rails that are all formed in the same manufacturing machine.

10. A loft flooring system as claimed in any preceding claim, wherein each head and/or foot is/are formed as an elongate beam.

11. A loft flooring system as claimed in any preceding claim, wherein the spanning beam or rail and/ or foot-supporting beam or rail has sliding engagement means for sliding inter-engagement with complementary sliding engagement means on the head of each of first leg and second leg.

12. A loft flooring system as claimed in claim 11, wherein the sliding engagement means comprises a flange and which is provided along at least one longitudinal edge of the spanning beam or rail, while the complementary sliding engagement means comprises.

13. A loft flooring system as claimed in claim 11 or 12, wherein the spanning beam or rail and/or the foot-supporting beam or rail is formed as a channel profiled form.

14. A loft flooring system as claimed in claim 11, 12 or 13, wherein the spanning beam or rail and/ or the foot-supporting beam or rail has a U-shaped profile and mounts onto the head and or foot of each of the first and second legs.