GB2592597A

GB2592597A - Drainage block

Info

Publication number: GB2592597A
Application number: GB2003001.1A
Authority: GB
Inventors: Piekarewicz Mihal
Original assignee: Iq Glass Solutions Ltd
Current assignee: Iq Glass Solutions Ltd
Priority date: 2020-03-02
Filing date: 2020-03-02
Publication date: 2021-09-08
Anticipated expiration: 2040-03-02
Also published as: GB2592597B; GB202003001D0

Abstract

The invention relates to a drainage block 100, comprising a lower block 150 and an upper block 110 for mating to the lower block. The upper block comprises an inlet 170 and an outlet 180, the inlet and the outlet connected by at least a drainage channel 120 between them for directing ingressed liquid to the exterior of the drainage block. The lower and upper blocks may have cooperating castellated surfaces 140, 160, wherein the upper block and lower block are mated by an adhesive or chemical bond. A later embodiment relates to a drainage duct comprising an elongate hollow body for cooperation with a drainage block.

Description

Drainage block

FIELD OF THE INVENTION

The present invention relates to drainage systems for window and door glazing units.

More specifically, the present invention relates to drainage blocks for glazing systems for managing drainage in a glazing unit.

BACKGROUND ART

Building design and fabrication necessarily varies from country to country, with water ingress being a significant issue in building construction in wetter climes. Water ingress, particularly around windows and doors, must be blocked as far as practical and any ingressed moisture provided with an outlet to avoid damage to and breakdown of the building structure.

It is usual for modern glazing to incorporate a modular or integrated drainage system to manage water and ingressed moisture from the immediate environment around the glazing unit. However, the consideration given to water ingress in the design process is largely dependent on the country of origin of the glazing unit and its general climate.

In many standard glazing systems, a drainage channel directing ingressed moisture toward the exterior of the building is located in or near the lower sill such that ingressed moisture may run out of the glazing structure under gravity. Alternative solutions to lower sill draining systems have been developed to solve the problem of gravity directed run off and drainage in glazing having a threshold flush with the surrounding structure.

In recent years, an increasing number of glazing units have been designed for installation with flush thresholds. In such systems, the lower sill is at or below threshold level, increasing the risk of pooling and stagnation of ingressed moisture. Standard drainage channels are often unsuitable as the lower sill is recessed or obscured. A common solution is to provide a soak away, whereby moisture is absorbed into the surrounding ground to the exterior of the building.

A known solution is shown in figure 1. A hollow aluminium block 70 is located on a structural substrate, usually comprising brick, block, concrete or screed. A thermoplastic structure 10 is arranged on the hollow aluminium block 70, and extends beyond the aluminium block 70 to occupy a space between an exterior drainage channel 60 and a side of the aluminium block 70. Both the aluminium block 70 and the thermoplastic structure 10 have an extent at least that of the footprint of the glazing with which it is installed.

The thermoplastic structure 10 is formed with hollows or cut outs 20 for ease of machining and fixation in situ, ease of manufacture, and reduced material costs. An upper surface of the thermoplastic structure 10 comprises ridges 30 for location and fixation of glazing unit frames or tracks 40, the latter for use where glazing units to be installed are required to slidably open.

The window frames or tracks 40 are typically fixed to the underlying substrate by at least a fixing bolt 50 that passes through the thermoplastic structure 10 and the aluminium box section 70. Likewise, a fixing bolt 50 secures the thermoplastic structure 10 and the aluminium box section 70 to the exterior drainage channel 60. However, it is known that through fixings, such as the fixing bolts shown, provide a pathway for moisture ingress into the assembled frame and related components.

The use of through fixings also compromises the structural integrity of the thermoplastic structure 10, significantly increasing the risk of the thermoplastic structure 10 buckling under the weight of the glazing unit, causing the frames or tracks 40 to warp, consequently impeding the movement of movable panes, and the potential formation of gaps between the window frames or tracks 40 and the panes supported by them.

The arrangement shown in figure 1 was subsequently adapted to address some of the drawbacks. The thermoplastic structure 10 was replaced with a solid thermoplastic block to avoid the problem of buckling or crushing of the thermoplastic structure 10.

The solid thermoplastic block comprised a lip for directing water toward a standard drainage channel. However, the block presented an additional weight burden positioned under an already heavy glazing assembly.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is disclosed a drainage block, comprising a lower block for mechanical fixation to a substrate, an upper block for mating to the lower block, and the upper block comprising an inlet and an outlet, the inlet and the outlet connected by at least a drainage channel therebetween for directing ingressed liquid to the exterior of the drainage block.

The lower block may comprise a castellated exterior surface, and the upper block may comprise a castellated exterior surface, wherein the castellated exterior surface of the upper block is arranged adjacent to and for interconnection with the castellated exterior surface of the lower block.

The upper block and the lower block may be mated by an adhesive or chemical bond, and the lower block may comprise at least a through hole for mechanically fixing the drainage block to a substrate. The inlet may be formed in a first longitudinal surface of the upper block, and the outlet formed in a second longitudinal surface of the upper block, the second longitudinal surface being arranged perpendicular to the first longitudinal surface. Alternatively, the second longitudinal surface may be arranged at an obtuse angle to the first longitudinal surface.

The drainage channel may comprise an inclined surface for guiding ingressed liquid from the inlet to the outlet. The inlet may extend the length of the first longitudinal surface, or may comprise a plurality of apertures in the first longitudinal surface. Alternatively, the drainage block may comprise a plurality of drainage channels located at intervals along the length of the upper block. Likewise, the outlet may extend the length of the second longitudinal surface, or may comprise a plurality of apertures in the second longitudinal surface. Where the drainage block comprises a plurality of drainage channels located at intervals along the length of the upper block, the drainage block will comprise a plurality of outlets located at intervals along the second longitudinal surface corresponding with the drainage channels.

The upper block may further comprise at least a connection portion on an upper exterior surface for locating a glazing unit frame or track.

The drainage block may be fabricated from a non-thermally bridging material.

In accordance with a second aspect of the present invention, there is provided a drainage duct, comprising an elongate hollow body for cooperation with a drainage block, the hollow body being defined by a roof comprising a plurality of openings therein, a floor arranged opposite the roof, and comprising a wall, an upright inner wall extending between the floor and the roof, the inner wall having an opening extending along its length, and an outer wall arranged opposite the inner wall and extending between the floor and the roof, wherein the floor, roof, inner and outer walls cooperate to define a void therebetween, and wherein the opening is located in the inner wall closer to the roof than it is to the floor, and the roof is recessed with respect to the inner and outer walls to define a trough between the inner wall and the outer wall.

The roof of the hollow body may comprise an outer surface comprising a first surface arranged parallel to the floor, and a second surface arranged between the first surface and the outer wall, the second surface being arranged at an acute angle to the outer wall.

The drainage duct may further comprise a grille arranged between the inner wall and the outer wall to provide a cover to the trough.

The drainage system may comprise a drainage block as described herein in combination with a drainage duct as described herein, wherein the drainage duct is arranged to extend longitudinally adjacent the drainage block, and the inner wall opening is arranged to cooperate with the drainage outlet of the upper block.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures in which; Figure 1 is a section view of a prior art solution as described herein; Figure 2 is a section view of an embodiment of a drainage block according to the invention; Figure 3 is a section view of an embodiment of a drainage block according to the invention; Figure 4 is a section view of an embodiment of a drainage block and a drainage duct according to the invention; and Figure 5 is a section view of a drainage duct according to the invention in situ. DETAILED DESCRIPTION OF THE EMBODIMENTS Figure 2 shows a section view of a drainage block in accordance with a first embodiment of the present invention. The drainage block 100 comprises a lower block 150 and an upper block 110. The drainage block 100 has footprint at least that of the footprint of the glazing unit frames or tracks adjacent which it will be installed.

The lower block 150 has a cross sectional area that is substantially quadrilateral. In the present embodiment, the profile is substantially rectangular for mechanical strength and stability. The depth of the lower block 150 is selected to carry a load commensurate with that of the glazing unit that rests on the drainage block 100, and provide mechanical stability. The cross sectional width of the lower block 150 is selected to cooperate with the upper block 110 and any flashings, trim, gutterings or soakaways used in conjunction with the window or door assembly mounted upon the drainage block 100. The lower block 150 is preferably formed of a discrete piece.

The lower block 150 has a castellated exterior surface 140 which, in use, is uppermost. The upper block 110 has a castellated exterior surface 160 for cooperation with the castellated exterior surface 140 of the lower block 150. In use, the castellated exterior surface 160 of the upper block is arranged on its lowermost face for locating the upper block 110 on the lower block 150. An adhesive may be used to bond the upper block 110 and the lower block 150 once located, the adhesive being applied between the castellated exterior surfaces 140, 160 of the upper and lower blocks 110, 150.

The upper block 110 has a quadrilateral cross sectional area. In the embodiment of figure 2, the upper block 110 is substantially rectangular. However, in further embodiments, the upper block 110 and/or the lower block 150 may be square, or rectangular in any orientation.

The upper block 110 has an inlet 170 in a first longitudinal exterior surface. The first exterior surface is arranged opposite the castellated surface 160. The upper block 110 has an outlet 180 in a second longitudinal exterior surface that extends between the castellated exterior surface 160 and the first longitudinal surface. The inlet 170 is arranged in the first longitudinal surface adjacent or proximal to a third longitudinal surface that extends between the castellated exterior surface 160 and the first longitudinal surface. The third longitudinal surface is arranged opposite the second longitudinal surface and is adjacent an inner sill 210 in use. The outlet 180 is positioned closer to the castellated exterior surface 160 than the first longitudinal surface.

The inlet 170 and the outlet 180 are connected by a drainage channel 120. The drainage channel 120 is arranged at an acute angle to the castellated exterior surface 160 and/or the first longitudinal surface. In use, the first longitudinal surface of the upper block 110 is uppermost. Any ingressed moisture or liquid that has reached the uppermost surface of the upper block 110 can drain through the drainage channel 120 to the outlet 180 by virtue of gravity. There may be several drainage channels 120 present in the upper block 110 spaced apart along the longitudinal extent of the drainage block 100.

The extent of the upper block 110 extends beyond that of the lower block 150 such that the first longitudinal surface is longer than the extent of the castellated surface 140, and the second longitudinal surface overhangs lower block 150. The lower block 150 has an exterior surface to which a membrane 240 is affixed, said exterior surface being arranged perpendicular to the castellated exterior surface 160 and recessed relative the second longitudinal surface of the upper block 110. This arrangement guides any drained moisture from the outlet 180 through a space between the membrane 240 and an exterior sill 250 so that ingressed moisture or liquid is vented to the exterior of the building.

The membrane 240 is positioned to provide a water tight barrier. The membrane 240 30 of the present embodiment is a known damp proof membrane. Any suitable material may be used. The membrane 240 extends from a fixing point in the surface of the lower block 150 adjacent the overhang of the upper block 1101 beyond the packing material 200 and a spacer 230, extending to a depth below the uppermost surface of the substrate 220. Ingressed moisture or liquid exiting the drainage channel 120 via outlet 180 is therefore guided and retained away from the lower block 150 by the damp proof membrane 240 such that moisture from the drainage channel 120 is prevented from entering a space between the lower block and the substrate 220. A gap between an exterior sill 250 and the damp proof membrane 240 provides drainage to ingressed moisture or liquid to the exterior of the building.

When the drainage block 100 is assembled in situ, the lower block 150 is positioned on a packing material 200 between the drainage block 100 and a substrate 220. The packing material 200 ensures that the lower block 150 is in the required orientation, and compensates for any irregularities or inconsistencies in the surface of the substrate 220. Substrate 220 may be a poured concrete or screed layer. In the present embodiment, in which the drainage block 100 underlies a raised window or door assembly, the substrate 220 is brick or block or any other commonly used building material for the exterior of a building.

In the embodiment of figure 2, a packing material 200 occupies a space between the substrate 200 and a membrane 190. The membrane is supported by longitudinal supports 230. A further region of packing material 200 is located between membrane 190 and lower block 150.

The membrane 190 extends between the inner sill 210 of the building and extends below the drainage block 100 to provide a moisture proof barrier between the inner sill 210, the packing material 200 adjacent the substrate 220 and any spacers 230 present for locating and orienting drainage block 100. The membrane 190 is located between an inner surface, which in this embodiment is an inner sill 210, and the drainage block 100 assembled with frame or track 220. The membrane 190 provides a damp proof barrier between the fabric of the building and the drainage block 100 and glazing, and can be arranged to cooperate with the membrane 240 to provide a barrier protecting the substrate 220 and internal fabric of the building in the form of inner sill 210 from moisture and liquid ingress. Although any suitable material may be used, the membranes 190, 240 of the present embodiment are ethylene propylene diene monomer (EPDM) synthetic rubber.

The membrane 190 extends adjacent the longitudinal supports and cooperates with membrane 240 to form a barrier preventing the drained moisture from drainage channel 120 from reaching substrate 220 inward of the exterior surface of substrate 220.

The lower block 150 is affixed to the substrate by mechanical means. Mechanical means includes mechanical fixings such as bolts, screws, nails or similar, retention by surrounding features or sub-assemblies, or simply under the weight of the drainage block.

The drainage block 100 is fabricated of a material with a low coefficient of thermal expansion. Preferably, the material selected has a maximum dimensional change of +/-1mm per metre over 25°C. Furthermore, the material is selected for compatibility with aluminium.

In the present embodiment, both the upper block 110 and the lower block 150 are formed of the same material. However, in further embodiments the upper block 110 and the lower block 150 may be formed of different and aluminium compatible materials, preferably with the same or very similar coefficients of thermal expansion.

Thermoplastic is preferred so as not to create a thermal bridge with the surrounding materials, for conformity with relevant building regulations, and for cost and availability.

The upper block 110 further comprises at least a connection portion 130 in the first longitudinal surface for location of and cooperation with a glazing unit frame or track 220. The frame or track 220 is of known construction and typically comprises a metallic or thermoplastic material. The number and arrangement of connection portions will be dependent upon the size and configuration of the frame or track 220, which will vary according to the glazing unit supported thereby.

The frame or track 220 is retained by connection portions 130 which cooperate with spacers on the underside of the frame or track 220 to provide a series of voids between the first longitudinal surface of the upper block 110 and the frame or track 220. The frame or track 220 is affixed to the upper block 110 by known means, including adhesive and through fixings such as bolts or screws.

Figure 3 shows a second embodiment of the drainage block 100, in which the drainage block 100 forms a sub-assembly with a glazing unit functioning as a door or patio window. The glazing unit is installed so that the exterior surface adjacent the glazing unit is substantially coplanar with the track 330 to form a flush threshold. The intemal fabric of the building in the second embodiment is an internal floor 310.

The drainage block 100 comprises a lower block 150 and an upper block 110. The upper block 110 has a first longitudinal exterior surface comprising a plurality of connection portions 130 for the location and retention of track 330 adjacent upper block 110. The track assembly of the present embodiment is adapted for use with large sliding or pivoting doors in an arrangement having four panes. As such doors can weigh a significant amount, the retaining sub assembly is more substantial than that for a smaller glazing unit or a glazing unit with fewer panes. Although the track assembly is shown as a solid component, it may be an assembly of several components required to facilitate the construction and operation of said sliding or pivoting doors. The track assembly 330 is therefore comprised of any known arrangement suitable for this application.

Upper block 110 comprises drainage channel 120 as per the embodiment of figure 2, in which the inlet 170 and the outlet 180 are connected by a drainage channel 120. The drainage channel 120 is arranged at an acute angle to the castellated exterior surface 160 and/or the first longitudinal surface. In use, the first longitudinal surface of the upper block 110 is uppermost. Any ingressed moisture or liquid that has reached the uppermost surface of the upper block 110 can drain through the drainage channel 120 to the outlet 180 by virtue of gravity. There may be several drainage channels 120 present in the upper block 110 spaced apart along the longitudinal extent of the drainage block 100.

The lower block 150 of the embodiment of figure 3 has depth approximately equal to that of the upper block 110. In further embodiments, the upper block 110 my have a greater depth relative the lower block 150, or vice versa.

The space for the packing material 200 on which the lower block 150 rests is retained by longitudinal supports 230 between substrate 320 and lower block 150.

The extent of the upper block 110 extends beyond that of the lower block 150 such that the first longitudinal surface is longer than the extent of the castellated surface 140, and the second longitudinal surface overhangs lower block 150. The lower block 150 has an exterior surface to which a membrane 340 is affixed, said exterior surface being arranged perpendicular to the castellated exterior surface 160 and recessed relative the second longitudinal surface of the upper block 110. This arrangement guides any drained moisture from the outlet 180 through a space between the membrane 340 so that ingressed moisture or liquid is drained to the exterior of the building via channel 270.

A membrane 390 is located between an inner surface 310, which in this embodiment is an internal floor, and the lower block 150. Membrane 390 is affixed to a third longitudinal surface of upper block 110 that extends between the castellated exterior surface 160 and the first longitudinal surface. The third longitudinal surface extends toward substrate 320 to provide a moisture resistant barrier between the drainage block 100 and substrate 320, and inner surface 310. The membrane 390 presents a barrier extending across the intersection between upper block 110 and lower block 150.

In a similar manner, membrane 340 is affixed to a side of lower block 150 opposite to the side to which membrane 390 lies adjacent, and extends between channel 270 and substrate 320 to provide a moisture proof barrier between lower block 150 and substrate 320, and channel 270.

The lower block 150 is affixed to the substrate 320 by mechanical fixings 260 extending through packing material 200. In the present embodiment, the substrate 320 is poured concrete. The bolt or screw heads of the mechanical fixings are recessed so that they are flush with the male portions of the castellated exterior surface 140 of the lower block 150.

The mechanical fixings 260 provide a potential pathway for moisture between the substrate 320 and lower block 150, but such ingress is thwarted by the unbroken line formed by the connection between upper block 110 and lower block 150. Membranes 340, 390 complete the moisture barrier between the lower block 150 and substrate 320, and upper block 110 and track assembly 330.

The channel 270 is disposed between track 330 and exterior ground surface 400. Below exterior ground surface 400, which, in the present embodiment, is a hard surface, is a soakaway 410. In further embodiments, the exterior ground surface 400 may be solid, particulate or any other suitable surface, including grass or bedding for plants.

The soakaway 410 is, in the present embodiment, a trench filled with particulate matter such as gravel. Any matter suitable to facilitate drainage and dispersal of moisture to the surrounding external ground may be used.

Although not shown in figure 3, channel 270 may comprise a grill extending between track 330 and exterior surface 400 to prevent solid matter such as leaves from entering channel 270 and causing blockage. In situ, the grill is preferably formed to have an upper surface flush with the exterior surface 400 and the base of track assembly 330 when the sliding or pivoting doors are in an open position.

Figure 4 discloses a further embodiment of drainage block 100 as a sub-assembly in a drainage system for a window/door having a flush threshold. The drainage system comprises a drainage duct 500. The drainage duct is arranged in channel 270 such that ingressed moisture exiting outlet 180 in the second longitudinal exterior surface of the upper block 110 enters the drainage duct 500 for dispersal at either or both longitudinal extents of the drainage duct 500.

In the embodiment of figure 4, lower block 150 has a large depth relative that of upper block 110, and is affixed to substrate 320 by fixing bolts 260. A membrane 420 is disposed between interior surface 310, the third longitudinal surface of upper block 100, and lower block 150, and packing material 200 and substrate 320.

Lower block 150 comprises a lip 440 that extends beyond the extremity of the second longitudinal exterior surface of the upper block 110. Lip 440 is arranged to cooperate with drainage channel so that ingressed moisture exiting outlet 180 is directed toward void 510 in drainage duct 500. Lip 440 is hook shaped to cooperate with a inner wall 540 of drainage duct 500, the area between which is sealed with a water proof sealant 430. The lip extends away from castellated exterior surface 140 of the lower block 150 and toward the substrate 320 in an L-shape. The inner wall 540 of the drainage duct 500 extends perpendicular to and toward castellated exterior surface 140 of the lower block 150 to occupy the space between the lip 440 and the remainder of the lower block 150. This arrangement is advantageous because ingressed moisture in either the void 510 in the drainage duct 500 must reach a threshold level before reaching the lip 440. The sealant 430 prevents ingress of moisture from the drainage duct 500 above the membrane 420. The combination of moisture proof connection of upper block 110, lower block 150 and sealant 430 forms a barrier between the substrate 320 and internal surface 310, and the glazing assembly and exterior surface 400. In all embodiments, the combination of components of the present invention therefore create a moisture proof seal between the interior of the building and the exterior.

Figure 5 shows the drainage duct 500 in further detail. The drainage duct 500 is an elongate member with an extent at least that of the drainage channel 270 in which it is to be placed. Drainage channel 270 is ordinarily arranged to the exterior of a glazing unit for the collection of ingressed moisture drained from the interior of the glazing assembly and/or its associated components, and atmospheric moisture including condensation and rain draining from the exterior of the glazing unit under gravity.

The drainage duct 500 is an elongate body for placement in drainage channel 270 and cooperation with drainage block 100. The drainage duct has a first length that forms a roof 520 comprising a wall. The roof 520 has a plurality of openings therein, arranged intermittently the length of the drainage duct 500. The openings allow ground water and precipitation to drain away from the immediate environs of the glazing unit, and through duct to areas of ground adjacent each extremity of drainage channel 270.

A floor 530 is arranged opposite the roof 520 and also comprises a wall. The floor 530 may have a planar interior face as well as a planar exterior surface. Alternatively, as shown in the present embodiment, the floor 530 may have a planer outer surface and an inner surface formed so that the inner face of the roof 520 is shortened and the inner face of the floor 530 is shortened, the outer faces of the roof 520 and the floor 530 remain unaffected.

An inner wall 540 is arranged perpendicular to the roof 520 and extends between the roof 520 and the floor 530, the inner wall 540 comprising an opening 550 extending the length of the inner wall 540. The opening 550 is arranged closer to the roof 520 than it is to the floor 530. In the present embodiment, the opening 550 is adjacent the roof 520.

An outer wall 560 is arranged opposite the inner wall 540 and extends between the roof 520 and the floor 530. The roof 520, the floor 530, the inner wall 540, and the outer wall 560 cooperate to form a void 510 therebetween.

The roof 520 is recessed with respect to the inner wall 540 and the outer wall 560 to form a trough 570 therebetween. The inner wall 540 and the outer wall 560 extend beyond the roof 520.

In the present embodiment, a grill 600 is arranged between the inner wall 540 and the outer wall 560 to provide a cover to trough 570. Grill 600 is arranged to provide a continuous surface between exterior ground surface 400, track 330, and interior floor surface 310. Grill 600 is arranged to prevent debris such as leaf matter and other foreign matter from entering trough 570, and by extension, entering void 510 through apertures in roof 520.

Opening 550 is arranged adjacent outlet 180 so that moisture exiting drainage channel 120 via outlet 180 is directed toward void 510. The extent of the upper block 110 extends beyond that of the lower block 150 such that the first longitudinal surface is longer than the extent of the castellated surface 140, and the second longitudinal surface overhangs lower block 150. The lower block 150 has an exterior surface to which a membrane 570 is affixed, said exterior surface being arranged perpendicular to the castellated exterior surface 160 and recessed relative the second longitudinal surface of the upper block 110. This arrangement guides any drained moisture from the outlet 180 to void 510 via membrane 570 that is dressed down over a lowermost portion of inner wall 540. Any moisture entering void 510 via the plurality of openings of the roof 520, and/or via the drainage channel 120 is directed into void 510 for evacuation via the extremities of the drainage duct 500.

It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention.

Claims

CLAIMS1. A drainage block, comprising: a lower block for fixation to a substrate; an upper block for mating to the lower block; and the upper block comprising an inlet and an outlet, the inlet and the outlet connected by at least a drainage channel therebetween for directing ingressed liquid to the exterior of the drainage block.
2. A drainage block according to claim 1, wherein the lower block comprises a castellated exterior surface, and the upper block further comprises a castellated exterior surface, wherein the castellated exterior surface of the upper block is arranged adjacent to and for interconnection with the castellated exterior surface of the lower block.
3. A drainage block according to claim 1 or claim 2, wherein the upper block and the lower block are mated by an adhesive or chemical bond.
4. A drainage block according to any preceding claim, wherein the lower block comprises at least a through hole for mechanically fixing the drainage block to a substrate.
5. A drainage block according to any preceding claim, wherein the inlet is formed in a first longitudinal surface of the upper block, and the outlet is formed in a second longitudinal surface of the upper block, the second longitudinal surface being arranged perpendicular to the first longitudinal surface.
6. A drainage block according to claim 5, wherein the drainage channel comprises an inclined surface for guiding ingressed liquid from the inlet to the outlet.
7. A drainage block according to any preceding claim, wherein the upper block further comprises at least a connection portion on an upper exterior surface for locating a glazing unit frame or track.
8. A drainage block according to any preceding claim, wherein the drainage block is fabricated from a non-thermally bridging material.
9. A drainage duct, comprising: an elongate hollow body for cooperation with a drainage block, 10. 11. 12.the hollow body being defined by a roof comprising a plurality of openings therein, a floor arranged opposite the roof, and comprising a wall, an upright inner wall extending between the floor and the roof, the inner wall having an opening extending along its length, and an outer wall arranged opposite the inner wall and extending between the floor and the roof, wherein the floor, roof, inner and outer walls cooperate to define a void therebetween, and wherein the opening is located in the inner wall closer to the roof than it is to the floor, and the roof is recessed with respect to the inner and outer walls to define a trough between the inner wall and the outer wall.A drainage duct according to claim 9, wherein the roof has an outer surface comprising a first surface arranged parallel to the floor, and a second surface arranged between the first surface and the outer wall, the second surface being arranged at an acute angle to the outer wall.A drainage duct according to claim 9 or claim 10, further comprising a grille arranged between the inner wall and the outer wall to provide a cover to the trough.A drainage system comprising a drainage block according to any one of claims 5 to 8, in combination with a drainage duct according to any one of claims 9 to 11, wherein the drainage duct is arranged to extend longitudinally adjacent the drainage block, and the inner wall opening is arranged to cooperate with the drainage outlet of the upper block.