GB2413805A

GB2413805A - Flood protection for buildings

Info

Publication number: GB2413805A
Application number: GB0409995A
Authority: GB
Inventors: Ray Wolfenden
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-05
Filing date: 2004-05-05
Publication date: 2005-11-09
Also published as: GB0409995D0

Abstract

Flood water is prevented from entering a building by providing a sealed junction between a wall structure 1, 2 and a floor structure 5 of the building. The sealed junction can be provided by sealing elements in or on each of the floor and wall structures being directly or indirectly sealingly joined to each other. A floor slab may be cast into or onto a wall structure of the building to form floor slab, wall and foundation of the building as a rigid structure. Alternatively a flexible restraint 41 may be provided between wall and floor structure. Sealing elements in or on the floor structure may be joined to those in or on the wall structure by a compression joint with sealing pressure provided by the weight of the overlying structure. Sealing may be provided around openings in the wall structure. Sealing may be provided by sealingly jointed or continuous waterproof membranes 7. Sealing may be provided around wall ties connecting inner 1 and outer 2 leaves of the wall. Alternatively sealing may be provided by sealingly jointed glazed bricks or dense engineering bricks. Alternatively sealing may be provided by closed cell expanding foam injected into a wall cavity.

Description

24 1 3805 - 1

FLOOD PROTECTION FOR BUILDINGS

This invention relates to flood protection for buildings.

Global climatic change is increasing the amount of rainfall in many parts of the world. More importantly, it is increasing the intensity of rainfall, leading to more frequent flooding of those areas with an established flood risk, and to the flooding of new areas with little or no flooding history. Such effects are bringing abject misery to large numbers of people unable to defend their buildings against floodwater penetration, unable to sustain repeated clean-up and repair operations, and unable to secure insurance to mitigate their loss.

Walls and floors provide an important secondary means of floodwater entry into buildings.

Walls and floors of buildings are designed and constructed to resist the penetration of moisture from the ground, and airborne moisture in the form of rain, sleet snow etc. particularly when driven by the force of the wind. These structural elements however are invariably not intended to resist immersion in floodwater, or to withstand hydrostatic pressure which naturally increases with ambient depth.

Walls in particular will accept floodwater penetration readily via a combination of inherent features including cracks and gaps caused by settlement, poor construction, weathering of materials etc. differential movement at door and window openings and service entry points, the existence of weep holes to allow drainage of moisture from the cavity, and the inherent porosity of the - 2 brickwork, blockwork or masonry itself. Where significant hydrostatic pressure is a factor, and/or where the natural underlying geology itself is porous, floodwater can migrate beneath a building with considerable force, scouring the foundations, penetrating the junction between wall and floor (particularly where there has been any settlement of the floor and/or walls), rupturing the dampproof membrane and stressing, perhaps even fracturing, the in-sin concrete floor slab.

Suspended floors of any type admit floodwater at will. Inundation of the underfloor void via ventilation grills for example, leads to floodwater breaching constructional components in the floor structure, and therefore flooding of the building interior. Any method of preventing floodwater penetration through the building structure will need to address these weaknesses and counteract these pressures.

Known solutions to floodwater penetration include 'rafting' of the floor slab - that is casting an in-situ, probably reinforced, concrete floor slab turned-down around the perimeter to form the wall foundations. The floor slab may also be turned-up to form the wall itself, or the inner leaf thereof. Such continuous concrete rafted construction is inherently strong, and with a cementitious or bituminous lining applied for example, also substantially waterproof. Such solutions have considerable disadvantage however in terms of cost, added construction timescales and equipment, complexity of effecting future building alterations and extensions, extra wall thickness reducing internal floorspace, and exposure of the membrane to damage and view. - 3

Alternatively, a waterproof lining might be applied in solution to a conventional wall and/or floor structure but possessing, by its very nature, significantly less structural and waterproof integrity than using rafted construction, and unacceptably low reliability for reasons already presented.

In each case, a lining must be applied to the sides of the wall facing the building interior or exterior where a solid wall is used, and so also where a cavity wall is used in order that such lining is not breached by wall ties spanning the cavity. Lining would therefore require an additional durable and visually acceptable finishing surface to be applied which may still leave it exposed to impact damage, and undetected accidental damage from structural movement, drilling of the wall for fixings etc. The presence of such damage may be all too real upon the next flooding event. Favourable weather conditions would also be required at the time of application of the membrane, otherwise unavoidable delays to constructional schedules would result.

It is a primary object of this invention therefore to provide simple, cost- effective, and wholly reliable means of preventing floodwater from penetrating a building through the walls and floor.

It is another object of this invention to provide such prevention means which are simple to install using conventional construction techniques, and easy to accept into on-site practice and procedure.

Another object is to provide means which enable structural and waterproof continuity between the walls and floor, is durable, protected from damage, and protected from view. - 4

Another object is to provide means which preserves future building flexibility, needs no finishing surface, and has no maintenance or operating requirement.

According to the present invention there is provided a means for preventing floodwater from penetrating a building such means resisting fracture or rupture and comprising either: ( 1) a sealed junction between the wall structure and the floor structure and/or (2) a sealing element or elements in or on such structure or structures such elements being sealably joined to each other and such element or elements being moveably sealably joined to sealing features in around or across intervening apertures.

An in-situ concrete floor slab may be cast into the wall structure of a building during construction thereby forming the slab, the wall, and the foundation as a single structurally-integrated unit and eliminating any differential movement between the wall and floor structures. A sealing element or elements forming part of the floor structure may therefore be safely brought into or onto the wall structure, or vice versa, resisting fracture or rupture of such element(s), and enabling wall elements to be sealably joined to floor elements.

Alternatively, a flexible joint may be formed between wall and floor structures thereby accommodating, as opposed to preventing, any differential movement and therefore also resisting fracture or rupture of the sealing element(s). Such joint may be sealably connected to the floor element and to the wall element, or replace either or both.

With an interlayer omitted from the flexible joint, and the floor slab allowed to fixably join with the wall structure during casting of the concrete, a further - 5 solution is provided for applications demanding a sealed junction between wall and floor structures where no relative movement can be tolerated, or where the junction will remain sealed should such movement occur.

The sealing element(s) in the wall structure may take the form of a sealably jointed or continuous waterproof membrane, sealed directly or indirectly to a floor membrane or forming a continuous part thereof, and sealed if appropriate to the wall structure. In the case of a cavity wall, specially adapted wall ties may connect together inner and outer leaves of the wall structure via a sealable joint through the wall membrane thereby supporting the membrane, maintaining the structural and waterproof integrity of the wall, and providing protection of the membrane from damage and view.

The sealing elements in the wall structure may also take the form of tiles sealed together at the joints, sealed to the wall structure, and sealably joined directly or indirectly to the floor sealing element(s). Again, in the case of a cavity wall, specially adapted wall ties may link inner and outer leaves of the wall structure sealably through the tiles.

The tile may be substituted by a glazed brick or block, or a dense engineering brick or block of no-or-low permeability any of which may also perform a structural role in a solid or cavity wall, and the adhesive may be mortar having a waterproof additive. In the case of a cavity wall, conventional ties may be used.

Alternatively, the sealing element(s) in the wall structure may take the form of a layer or layers of waterproof material applied in solution to a surface of the wall - 6 structure such layer or layers being sealably joined directly or indirectly to the floor sealing element(s), and being overlaid if necessary with a protective and/or aesthetic face, for example brickwork, blockwork, masonry, slips, tiles, render or plaster. Again, in the case of a cavity wall, specially adapted wall ties may link inner and outer leaves of the wall structure sealably through the waterproof material.

A compression joint between the sealing elements in the wall and floor structures may be formed in the inner or outer leaves of the wall using the weight of overlying construction to increase the sealing pressure.

The wall sealing element(s) may further take the form of closed-cell expanding foam of suitable formulation injected into the wall cavity during or following construction of the wall. The foam may thereby selfseal or be sealably joined to the floor sealing element(s) and/or to the flexible joint and to the opposing faces of the inner and outer leaves of the wall with or without wall ties, thereby providing a strong, durable and waterproof building perimeter resisting hydraulic pressure, rupture or fracture, and protection from damage and view.

In all of the above provisions, structural integrity of the wall and floor, thermal insulation, drainage, protection from ground moisture, and other relevant performance requirements are either provided by the present disclosure, or accommodated normally.

Sealable junctions may be provided between the wall sealing element(s) and openings in the wall structure for exurple doors and windows below the level to which flood protection is required, and service entry and exit points may also be sealably joined to the membrane where appropriate.

Wall and floor sealing element(s) may assume any position within or upon wall and floor structures, and may replace or subsume the role of any feature within such known structures. Such wall structures may be of solid or cavity construction. Any embodiment disclosing a sealed junction between wall and floor structures may be used in combination with any embodiment disclosing a sealing element or elements within or upon such structures, and any embodiment may be used independently. The provisions of any embodiment may be combined into any other embodiment, as necessary and as appropriate.

Specific embodiments of the invention will now be described by way of example, with reference to the accompanying drawings in which: Figures 14 show a construction sequence in the first embodiment: Figure I is a cutaway cross-section showing a floor slab cast in-situ into and onto a cavity wall, with the outer leaf extending above floor level; Figure 2 is a cutaway cross-section showing a waterproof floor membrane laid over the floor slab and the outer leaf, and a screed cast in-situ over insulation and the membrane; Figure 3 is a cutaway cross-section showing the inner leaf built up above anticipated flood level, and a wall membrane installed on the special wall ties; Figure 4 is a cutaway cross-section showing the outer leaf built up on the sealed compression joint between wall and floor membranes, and the wall insulation installed; - 8 Figure 5a is a vertical cutaway cross-section showing the wall membrane push- fitted onto the first part of a special wall tie installed in and on the inner leaf, and the second part offered up; Figure sb is a vertical cutaway cross-section showing the second part of a special wall tie screwed onto the first part, wall insulation installed, and the outer leaf built up; Figure 6a is a vertical cutaway cross-section in the first embodiment showing the sealed compression joint between the wall and floor membranes; Figure 6b is a horizontal cutaway cross-section in the first embodiment showing the pressure-sealed joint between the wall membrane and a perimeter frame; Figure 7a is a vertical cutaway cross- section in the second embodiment showing the sealed compression joint between the floor membrane and a jointing strip bonded to the tile sealing elements in the wall structure; Figure 7b is a horizontal cutaway cross-section in the second embodiment showing the pressure-sealed joint between the tile sealing elements in the wall structure and a perimeter frame; Figure 8a is a vertical cutaway cross-section in the fourth embodiment showing the pressure-sealed joint between the floor membrane and an in-situ foam sealing element in the wall structure; Figure 8b is a horizontal cutaway cross-section in the fourth embodiment showing the pressure-sealed joint between the in-situ foam sealing element in the wall structure and a perimeter frame; Figure 9 is a vertical cutaway cross-section showing the flexible joint between the wall and floor structures in the fifth embodiment, and the wall and floor membranes.

In a first embodiment of the invention shown in Figures 1-4, inner and outer leaves 1,2 of a cavity wall 3 are constructed off a concrete foundation 4 extending around a building perimeter. A concrete floor slab 5 is cast in-situ into and onto the cavity wall thereby forming the slab, the wall, and the foundation as a single structurally-integrated unit. Such unit is inherently able to resist movement, settlement, stress, and fracture caused by hydraulic pressure and by repeated saturation and drying-out of the ground. In particular, using simple construction techniques, such unit resists differential movement causing fracture of the joint between wall and floor structures.

The floor slab 5 may optionally further extend horizontally into the space occupied by the outer leaf 2.

In Figure 2, a waterproof floor membrane 7 is laid over both the slab and the upwardly extending outer leaf, the inner leaf starter course 8 and the floor insulation 9 are laid, and a screed lo is cast in-situ over the insulation. In this way, a floor membrane may be safely brought across the rigid junction with the wall structure to prevent future fracture or rupture of the membrane by hydraulic pressure or ground movement, to provide immediate and ongoing - 10 protection of the membrane from impact damage or 'scouring' for example, and to bring the exposed perimeter of such membrane to a position where it can be sealably joined to a wall membrane.

The floor membrane may alternatively be brought up over both inner and outer leaves both raised up above the floor level 6, or such membrane may extend directly through the whole wall structure at floor level.

In Figure 3, the inner leaf I is built up above anticipated floodwater levels using the specially adapted wall ties I I (shown in detail in Figures sa and sb) fixed at specified centres, and a wall membrane 12 sealably joined together as necessary and installed in the position shown, around the building perimeter exposed to flooding. The wall ties I I sealably penetrate the wall membrane 12 thereby structurally connecting the inner and outer leaves together in the manner of known ties, whilst also retaining the membrane in position and maintaining waterproof continuity around the building.

The upper extent 13 of the wall membrane 12 iS tucked into, and sealably restrained in, a horizontal joint-line or groove in the inner leaf thereby preventing the movement of moisture in the cavity onto the dry' side of the membrane, and so into the building interior. The lower extent 14 of the wall membrane is tucked into a horizontal joint-line in the outer leaf together with the floor membrane 7 from the floor structure, both membranes being held together in a sealed compression joint 15 shown in Figure 6a, such joint extending into any returns of the outer leaf and utilising the weight of overlying construction of the outer leaf to increase sealing pressure. The membranes may be sealably joined together directly, or using an interlayer 16.

Rupture of the wall and floor membranes under compression both at the joint and, as shown in Figure 8a, at other locations where they pass under or into an external or internal wall, may be prevented by sandwiching the membrane between fibre-based bituminous strip 17 or alternative which acts to sealably cushion the membrane(s). The sealed cushion may be bedded on mortar 18 and have a mortar overlayer 19.

Figure 4 shows the resultant structure, wall insulation 20 and notional locations of wall ties I I. The waterproof tray effectively formed across the whole building by the membranes 7,12 in the wall and floor structure, may be a single continuous membrane or membranes of the same or different materials sealably joined together. The floor membrane 7 may replace a conventional damp-proof membrane, and the joint 15 and the membrane 7 may replace a conventional damp-proof course. The wall membrane 12, together with the provision of weep-holes in the outer leaf, may allow moisture and floodwater to drain freely from the cavity.

Where necessary, joins in the wall and floor membranes may be made using established methods either separately or together and including for example, thermal or solvent welding, single-sided and/or double-sided self-adhesive tape or strip of appropriate specification used as an interlayer, underlayer or overlayer, waterproof adhesive (for example epoxy resin) etc. with or without compression means to hold the join in permanent sealable conjunction.

Where an opening interrupts the waterproof continuity of the wall membrane 12, the membrane may be brought during construction through the outer leaf 2 to the external face of the building where it may be sealably terminated around - 12 the opening. The membrane may also be sealably joined around the relevant perimeter of the opening to the receiving frame of an aperture sealing panel for example that disclosed in Applications GO 2331031 and GB238 1 032 being temporarily installed when flood conditions threaten.

Alternatively, as shown in Figure fib, the return of the outer leaf 2 into an opening may be used to bring the wall membrane 12 through a mortared joint, and the membrane may be terminated projecting from the face of such return.

A door, window or other perimeter frame 21 fixably installed in such opening may have a linear cavity around the relevant perimeter to accept the membrane projection and to accept expanding foam 22 injected to pressure- seal the membrane to the frame and the frame to the wall, and to stop-up all routes around the frame for floodwater under pressure.

The lower extent of the membrane 12 may be held with the floor membrane 7 in the sealed compression joint 15 extending also into tine return of the outer leaf. The perimeter frame 21 may be sealably joined to the receiving frame of any aperture sealing panel, or may be formed as an integral part thereof.

Where the wall and floor are required to be thermally insulated, the inner leaf may also be built-up by at least one course above the finished floor level in the same way as the outer leaf shown in Figure 1. The space between the leaves may then be insulated prior to laying the floor membrane over the slab and the leaves, the floor insulation laid above the membrane as far as the inner leaf, and the screed cast - all in a single operation. Wall insolation may be applied on either the 'dry' or 'wet' side of the wall membrane. - 13

Where ground conditions and the natural geology dictate, the floor slab may be reinforced and such reinforcement may extend down into the subfloor wall cavity; additional compaction of the sub-floor base may be specified; and the base material may itself be of a 'dry-mix' concrete specification or of aggregate grouted up solid with a concrete slurry, all so as to promote further stability and resistance to movement, and to limit the effects of scouring.

Materials for wall or floor membranes may be any resilient waterproof material either reinforced ancl/or formulated if necessary for high puncture or tear resistance for example rubber, synthetic rubber and/or plastics and other components made from metal or plastics material or a combination of these.

Any metal components would need to be of a non-rusting or corroding type, or be permanently coated or encapsulated to avoid such effects.

Figure sa shows a specially adapted wall tie 11 in which a first part has a tail 23 fixably restrained in a mortar joint-line 24 of the built-up inner leaf 1, the tail having a flange 25 fixably joined thereto or as an integral part thereof, and the flange having a threaded stud 26 at its' centre. The flange is butted up to the internal face of the inner leaf I, and has a ring-seal or sealing gasket 27 incorporated into its' exposed face.

A second part also has a tail 28, a flange 29 having a ring-seal or sealing gasket 30, and an internally threaded cylinder 31 axially joined between the two or as an integral part thereof. The flange 29 has a threaded hole at its' centre providing threaded continuity with the internal threads of the cylinder 31, and such flange may also have a sharp annular lip around the entrance to such hole. - 14

When the second part is offered up to the first part as shown in Figure 5a, the two parts may be connected using a firm pushand-turn action to enable th sharp annular lip to punchthrough the wall membrane 12 whilst also engaging the threaded stud 26 with the threaded flange 29 and cylinder 31. Screwing the two parts together enables the flanges to sealably sandwich the wall membrane 12, and for the outer leaf to be built up structurally connected to the inner leaf as shown in Figure sb. Alternatively, the wall membrane may be punched-through prior to connecting up the wall ties, enabling such membrane to be pushfitted on to the first part and support such membrane as construction progresses.

The external surface of the cylinder may have flats 32 to enable the sealing pressure between the flanges and the membrane to be controlled, for example by using a torque wrench, and the tail 28 may be rotationally free-to-move at its' junction with the cylinder to allow insertion of such tail into both horizontal or vertical mortared joint lines as the outer leaf is built up. The tie may also incorporate a flange 33 push- fitted onto the tail 28 to allow insulation batts 20 to be restrained in position within the cavity as the outer leaf is built up.

Each or either opposing face of the flanges in contact with the membrane may have an annular groove or cavity connected to their other face by a hole or holes into which adhesive or expanding foam may be injected, thereby providing an additional or alternative method of permanently sealing the membrane to the tie. As an alternative to injection, one or two-part adhesive may be retained in either or both annular grooves or cavities, such adhesive being released by the action of screwing the first and second parts together and thereby to seal membrane and tie. -

Ring-seals or gaskets for the specially adapted wall ties may be made from any flexible, resilient compressible material for example rubber, synthetic rubber and/or plastics, and other components made from metal or plastics material or a combination of these. Any metal components would need to be of a non- rusting or corroding type, or be permanently coated or encapsulated to avoid such effects.

In a second embodiment of the invention shown in Figures 7a and 7b, the sealing elements in the wall and/or floor structure may be waterproof tiles 35 sealably fixed to the substrate using waterproof adhesive 36 of appropriate specification and sealed together at the joins using waterproof grout 37. The grout and the adhesive may be the same material.

Where tiles 35 are used as the wall element, each specially adapted wall tie I may sealably penetrate a hole made through such tiles thereby structurally connecting inner and outer leaves together; the upper extent and the lower extent of the tiles may be returned into the wall structure, or the tiles may remain substantially in the same plane and be sealably joined to the floor membrane 7 by the adhesive 36; and the return of the outer leaf 2 into an opening may be used to sealably join the tiles to a door, window or other perimeter frame 21 and to an aperture sealing panel, and thereby maintain waterproof continuity around the building. The lower extent of the tiles 35 may be held with the floor membrane 7 in the sealed compression joint 15 shown in Figure 7a also extending into any return of the outer leaf.

Alternatively, any part of the perimeter of the tiles may be bonded to a jointing strip 38 to translate the membrane from an inflexible state (represented by the - 16 tile) to a flexible state thereby able to accept any differential movement, able to be conveniently terminated in the joint shown in Figure 7b using expanding foam 22 injected to pressure- seal such jointing strip to the frame 21, and the frame 21 to the wall, and able to be held together with the floor membrane 7 in the sealed compression joint 15 shown in Figure 7a also extending into any return of the outer leaf.

The jointing strip may be made from any flexible, resilient, waterproof material for example rubber, synthetic rubber and/or plastics, and the tile made from ceramic, metal or plastics material or a combination of these. Any metal components would need to be of a non-rusting or corroding type, or be permanently coated or encapsulated to avoid such effects.

The tile may be substituted by a glazed brick or a dense engineering brick of no-or-low permeability either of which may also perform a structural role in a solid or cavity wall, and the adhesive may be mortar having a waterproof additive. In the case of a cavity wall, conventional ties may be specified and a cavity tray may be inserted into the sealed compression joint 15 in place of the jointing strip 38.

In a third embodiment, the sealing elements in the wall and/or floor structure may be a bituminous or cementitious layer or layers applied in solution to a surface of the wall structure. Where such layer or layers are used as the wall element, the specially adapted wall ties I I may sealably penetrate the layer or layers, and the return of the outer leaf 2 into an opening may be used to sealably join the layer or layers to a door, window or other perimeter frame 21 and to an aperture sealing panel. - 17

Alternatively, any part of the bituminous or cementitious layers may be bonded to the jointing strip 38 shown in Figures 7a and 7b to translate such layers flom an inflexible state to a flexible state thereby able tO accept any differential movement, able to be conveniently terminated in the pressure-sealed joint shown in Figure 7b, and able to be held together with the floor membrane in a sealed compression joint 15 shown in Figure 7a extending into any returns.

An annular scrim or scrims applied between the flange of the first part of the special wall tie and the tile adhesive of the second embodiment, or such flange and the cementitious or bituminous layer or layers of the third embocliment, may be used to form a durable seal between the tie and the wall element(s).

Similarly, a scrim or scrims may be used in either embodiment between the jointing strip and the tile adhesive, or such strip and such layer or layers.

The layer or layers may be overlaid if necessary with a protective and/or aesthetic face, for example brickwork, Clockwork, masonry, slips, tiles, render or plaster.

The scrim(s) may be made from a membrane, mesh or weave of natural or synthetic origin which may be impregnated, textured, and/or coated t promote adhesion and/or binding quality.

In a fourth embodiment shown in Figures 8a and 8b, the sealing element in the wall structure may take the form of closed-cell expanding foam 39 of suitable formulation injected into the wall cavity during or following construction of the wall to at least the height to which protection from flooding is required. The foam may be of a same or similar type to that conventionally used for cavity wall insulation, for example ureaformaldebyde (UF) or polyisocyanate foam, - 18 but where the substrate islikely to be damp and/or where high adhesion is required appropriate water-based alternatives may be used.

As shown- in Figure Sa, the foam 39 may thereby self-seal to the floor membrane 7 and to internal faces of the inner and outer leaves of the wall with or without wall ties, thereby providing a strong, durable and waterproof building perimeter resisting hydraulic pressure, rupture or fracture, and protection from damage and view. As shown in Figure 8b, an upstanding waterproof membrane 40 may be brought through a mortared joint of any return of the outer leaf to a door, window or other perimeter frame 21 to prevent the penetration of floodwater at this juncture and to provide a clean edge to which foam 39,22 injected into the wall and frame cavities may self- seal.

Since the foam 39 sealably links the membranes 7,40, the sealed compression joint 15 referred to in the previous embodiments need not be used, and where a sealed cushion for the membrane 7 is provided at the point where it passes through the inner leaf such membrane may be optionally terminated projecting into the cavity rather than in a second sealed cushion 46 in the outer leaf shown in Figure 8a. In this case however, a conventional damp-proof course in the outer leaf may still be required. No weep-holes are necessary.

In a fifth embodiment shown in Figure 9, a flexible joint is formed between wall and floor structures thereby accommodating, as opposed to preventing, any differential movement and therefore also resisting fracture or rupture of the sealing element in or on such structures. A flexible restraint 41 is inserted into - 19 a mortared joint-line of the inner I, or inner and outer 2, leaves of a wall as the wall is built up to slab level, such restraint projecting horizontally out from the exposed face of the inner leaf. As work progresses, the wall cavity is filled with concrete 42 above and below the restraint 41 thereby fixably joining the inner and outer leaves together, and fixably joining the wall structure with such restraint.

A concrete slab 5 is cast above and below such projection and up to an interlayer of expanded foam 43 or other material having no or low intrinsic strength and/or adhesion which prevents the slab from fixably joining with the inner leaf. A flexible floor membrane 7, for example having high tear and puncture resistance, is laid on top of the slab, and a tuck 44 to accommodate movement of the slab without fracture or rupture of the membrane 7 is folded in around its' perimeter adjoining the inner leaf. The inner leaf is further built up, the insulating layer 9 applied on top of the membrane 7, and the screed l o similarly separated from the inner leaf is applied on top of the insulation.

During casting of the slab, a linear groove 45 formed with expanded foam or other flexible material may be provided in the edge of the slab immediately adjoining the membrane. The projecting restraint 41 may be joined to the material forming the groove, and/or the interlayer 43 or form an integral part thereof, or they may be entirely separate, and such restraint may have a ribbed or punctuated surface to aid fixity with the slab and with the wall. The restraint may be constructed of extremely durable material or materials, for example in the manner of vehicle lyre casings, using reinforced rubber and/or plastics, and the amount of relative movement between the wall and floor structures - 20 carefully controlled by the specification of the projecting membrane, the tuck, the groove, and the interlayer.

With the interlayer omitted, and the floor slab allowed to fixably join with the wall structure during casting of the concrete, a further solution is provided for applications demanding a sealed junction between wall and floor structures where no relative movement can be tolerated, or where the junction will remain sealed should such movement occur.

Figure 9 adopts the arrangement of wall membrane, specially adapted wall ties, and wall insulation otherwise shown in Figures 4, sa and b, and 6a, but any alternative disclosed herewith may be applied.

Whilst the foregoing description discloses wall and floor sealing elements by way of example in specific dispositions within wall and floor structures, such membranes may assume any position within or upon such structures, and may replace or subsume the role of any feature within such known structures.

Any wall structure may be of either solid or cavity construction using known materials including timber frame. Any embodiment disclosing a sealed junction between wall and floor structures may be used in combination with any embodiment disclosing a sealing element or elements within or upon such structures, and any embodiment may be used independently. The provisions of any embodiment may be combined into any other embodiment, as necessary and as appropriate. Materials and details other than those disclosed may be used. - 21

Services into and out from buildings at risk of flooding may generally be arranged to penetrate the building structure above the level to which flood protection is provided, and therefore not to penetrate the mall and floor membranes. Where this is unavoidable, in the case of drainage pipes for example, a pipe entry seal disclosed in GB2373258B may be used and/or close-fitting sleeves sealably bonded to the pipe either side of the membrane, each sleeve having a circumferential flange sealably joined to the pipe and sealably bonded to the membrane. - 22

Claims

( 1) A means for preventing floodwater from penetrating a building such means resisting fracture or rupture and comprising either: ( I) a sealed junction between the wall structure and the floor structure and/or (2) a sealing element or elements in or on each or either structure such elements being sealably joined to each other, directly or indirectly.

(2) A means for preventing floodwater from penetrating a building as claimed in Claim I having an in-situ concrete floor slab cast into or onto the wall structure with or without reinforcement thereby forming the slab, the wall, and the foundation as a rigid unit eliminating any differential movement between wall and floor structures.

(3) A means for preventing floodwater from penetrating a building as claimed in Claim I having a flexible restraint between wall and floor structures thereby accommodating any differential movement between such structures.

(4) A means for preventing floodwater from penetrating a building as claimed in Claim 3 having the flexible restraint sealably connected to the floor element and/or the wall element, or replace either or both.

(5) A means for preventing floodwater from penetrating a building as claimed in Claim 3 having an interlayer separating wall and floor structures. - 23

(ff) A means for preventing floodwater from penetrating a building as claimed in Claim 5 having the interlayer omitted thereby providing a rigid junction between wall and floor structures or a sealed junction should any movement occur.

(7) A means for preventing floodwater from penetrating a building as claimed in Claim 1 in which the sealing element or elements in the floor structure are sealably joined to the sealing element or elements in the wall structure via a sealed compression joint utilising the weight of overlying construction to increase sealing pressure.

(8) A means for preventing floodwater from penetrating a building as claimed in Claim 7 in which the sealed compression joint comprises an interlayer between the wall and floor element or elements with or without an underlayer and/or an overlayer.

(a) A means for preventing floodwater from penetrating a building as claimed in Claim I in which the wall elerrent or elements is/are sealably terminated around an opening.

( 1 o) A means for preventing floodwater from penetrating a building as clairred in Claim 9 in which the wall element or elements is/are sealably joined directly or indirectly to a door, window or other perimeter frame in an opening or to the receiving frame of an aperture sealing panel.

( I I) A means for preventing floodwater from penetrating a building as claimed in Claim I in which the sealing element or elements in or on the wall - 24 and/or floor structures are sealably jointed or continuous waterproof membranes.

( 12) A means for preventing floodwater from penetrating a building as claimed in Claim I I in which the wall and floor membranes are together a single continuous membrane.

( 13) A means for preventing floodwater from penetrating a building as claimed in Claim I I in which the wall and/or floor membranes are sealed to the wall and/or floor structures.

( 14) A means for preventing floodwater from penetrating a building as claimed in Claim I I having at least one tuck or corrugation in a floor merrbrane adjoining the wall structure.

( 15) means for preventing floodwater from penetrating a building as claimed in Claim I I in which specially adapted wall ties connect together inner and outer leaves of a wall structure via a sealable joint with the wall membrane.

( 16) A means for preventing floodwater from penetrating a building as claimed in Claim 15 having a wall tie in two parts each having mutually engaging features.

( 1 7) A means for preventing floodwater from penetrating a building as claimed in Claire 13 in which each part leas complementary flanges sealably - 25 engaging the wall membrane therebetween as the parts are engaged together.

( 18) A means for preventing floodwater from penetrating a building as claimed in Claim 17 in which either or both flanges have ring-seals or gaskets.

( I a) A means for preventing floodwater from penetrating a building as claimed in Claim 17 having a threaded stud on one flange engaging with a threaded hole in the other.

(20) A means for preventing floodwater from penetrating a building as claimed in Claim 16 either part having a sharp annular lip punchingthrough the membrane whilst engaging the other.

(21) A means for preventing floodwater from penetrating a building as claimed in Claim 16 in which a hole is formed in the membrane prior to engaging the two parts.

(22) A means for preventing floodwater from penetrating a building as claimed in Claim 19 in which the threaded hole extends into a cylinder fixably joined to the flange or forming an integral part thereof.

(23) A means for preventing floodwater from penetrating a building as claimed in Claim 22 in which the external surface of the cylinder may have flat to enable the sealing pressure between the flanges and the membrane to b controlled.

(24) A means for preventing floodwater from penetrating a building as - 26 claimed in Claim 16 having a tail on either or both parts, either or both of which may be rotationally free-to-move to allow fixing of such tail onto or into the inner and outer leaves.

(25) A means for preventing floodwater from penetrating a building as claimed in Claim 16 incorporating a feature on either part to allow insulation batts to be restrained in position in or upon tire wall structure.

(26) A means for preventing floodwater from penetrating a building as claimed in Claim 17 in which each or either opposing face of the flanges may have an annular groove or cavity into which adhesive or expanding foam may be injected.

(27) A means for preventing floodwater from penetrating a building as claimed in Claim 26 in which adhesive is retained in as opposed to injected in either or both annular grooves or cavities.

(28) A means for preventing floodwater from penetrating a building as claimed in Claim 27 in which the adhesive is released by the action of engaging the parts of the tie together.

(29) A means for preventing floodwater from penetrating a building as claimed in Claims I 1-28 (excluding 12, 14 and 20) in which waterproof tiles sealably joined together are substituted for either or both waterproof membrane(s) in or on the wall and floor structures.

(30) A means for preventing floodwater from penetrating a builder, as - 27 claimed in Claim 29 having a jointing strip sealably joining the tiles to any feature.

(31) A means for preventing floodwater from penetrating a building as claimed in Claim I in which the sealing elements in or on the wall and/or floor structure(s) are sealably jointed glazed bricks or blocks or dense engineering bricks or blocks.

(32) A means for preventing floodwater from penetrating a building as claimed in Claim 31 in which such bricks or blocks replace conventional materials in a solid or cavity wall.

(33) A means for preventing floodwater from penetrating a building as claimed in Claim 31 having a jointing strip sealably joining the bricks or blocks to any feature.

(34) A means for preventing floodwater from penetrating a building as claimed in Claims 1 1-28 in which a bituminous or cementitious layer or layers is/are substituted for either or both waterproof membrane(s) in or on the wall and floor structures.

(35) A means for preventing floodwater from penetrating a building as claimed in Claim 34 having a jointing strip sealably joining the bituminous o cementitious layer or layers to any feature.

(36) means for preventing floodwater from penetrating a building as - 28 claimed in Claims I 1, 29 and 34 having an annular scrim or scrims reinforcing the joint between the special wall tie and either the membrane the tile or the layer(s).

(37) A means for preventing floodwater from penetrating a building as claimed in Claim I in which the sealing element in the wall structure is closed- cell expanding foam injected into the wall cavity.

(38) A means for preventing floodwater from penetrating a building as claimed in Claim 37 in which the foam self-seals to any feature it contacts.

(39) A means for preventing floodwater from penetrating a building as claimed in any preceding claim such elements assuming any position within or upon such structures and supplementing replacing or subsuming the role of any feature within or upon such known structures.

(40) A means for preventing floodwater from penetrating a building as claimed in any preceding claim used in combination with any other claim.

(41) A means for preventing floodwater from penetrating a buildin substantially as described herein with reference to Figures 1-9 of the accompaning drawings.

(42) The use of a means for preventing floodwater from penetrating a building as claimed in any preceding claim substantially as hereinbefore described.