GB2545208A - Protecting vaults - Google Patents

Abstract

A vault can be made damp proof by arranging a waterproof membrane 6 adjacent to an internal surface 50 of the vault using a structure of spaced elongate elements 15 to retain it. Preferably, elements 15 are flexible plywood planks which curve to follow the arched or domed vault surface (fig.1,54), with straight, vertical portions along vertical walls with studwork inserted in-between. The structure may be braced against the floor, the internal vault surface or a horizontal rail of the structure with elements joined by glue or screws. An upper portion of the membrane may be held using adjustable props (fig.1,11) braced against a straight upper strip 9 running along the vault apex; the upper strip may have parallel rebates 10, for receiving the curved strips 15. Additional membrane sections, attached to the upper membrane, may be used to cover vertical surfaces. A floor membrane may be provided, with an upstanding membrane (fig.1,3) around the lowermost parts of the internal surface taped to the waterproof membrane covering the vault ceiling or walls. Plasterboard may be attached to the framework, and flooring laid over the floor membrane. The apparatus used in the method is also claimed.

Description

PROTECTING VAULTS Background to the Invention [0001] This invention relates to a method and apparatus for damp proofing a vault. The term "vault" as used herein means a chamber, usually underground, and usually having an arched stone roof; but the invention can also be applied to above-ground buildings and those with flat ceilings.

[0002] In order to prevent moisture from entering a vault, a polymeric membrane can be attached to the walls and ceiling of the vault as a liner. Where the walls and ceiling are stone, anchors in the form of screws or the like can be used to attach the membrane. These anchors extend through holes in the membrane, which can allow moisture to pass through, and can also weaken the stone.

Summary of the Invention [0003] The invention provides a method of damp proofing a vault, comprising: arranging a waterproof membrane adjacent an internal surface of the vault; and forming a structure comprising mutually spaced elongate elements to retain the membrane between the internal surface and the structure.

[0004] The structure can have a shape essentially mimicking that of the vault. The structure may, however, lack a floor. In one embodiment, elements of the structure comprise wooden or wood-based strips or planks, such as strips of plywood. If the elements are flexible, they can be curved to follow an arched or domed surface of the vault.

[0005] The step of arranging the membrane adjacent the surface can include the use of one or more adjustable props braced from the floor, to retain at least an upper part of the membrane against an upper surface of the vault. Simultaneously, an upper elongate element can be placed between the prop(s) and the upper surface. For the common kind of vault having a generally constant arched cross-section, this upper element can comprise a generally straight strip, extending along the apex of the arched upper surface. The upper element can be formed with parallel rebates for receiving curved elements.

[0006] After propping the upper element in place, additional membrane sections can be attached to the upper part, for example with strong waterproof tape. These additional sections can be cut to fit further surfaces of the vault, such as vertical walls.

[0007] Formation of the structure can include the formation of vertical parts to fit vertical walls of the vault, and to retain vertical parts of the membrane. Such vertical parts may include horizontal rails and can usefully support the upper element and/or the curved elements. Alternatively, the curved elements, which may include straight, vertical portions, may also (or only) be supported by being braced against a floor and/ or the internal surface.

[0008] Elements of the structure can be joined together by gluing and/or screwing.

[0009] A preliminary step in the method may comprise laying a waterproof floor membrane on a floor of the vault. An upstanding membrane may extend from the floor membrane around lowermost parts of the internal surface. A suitable floor may be laid on top of the floor membrane. The main waterproof membrane can be taped or otherwise joined to the upstanding membrane.

[0010] After the structure has been formed, additional studwork can be inserted between the vertical elements. An adhesive can be used to bond this studwork to the additional membrane sections and relieve the load on the tape or other attachment between the upper membrane part and the additional membrane sections. Plasterboard can be attached to the studwork and lattice elements to form a smooth wall.

[0011] The invention also provides apparatus for damp proofing a vault, the apparatus comprising a structure including mutually spaced, elongate elements arranged adjacent an internal surface of the vault, and a waterproof membrane retained against the internal surface by said structure. For the common kind of vault having a generally constant arched cross-section, an upper element of the structure can comprise a generally straight strip, extending along the apex of the arched upper surface. The upper element can be formed with parallel rebates receiving curved elements or ribs.

[0012] The membrane can comprise overlapping membrane sections, joined to each other by tape. The structure can comprise additional vertical studwork elements, bonded to vertical ones of the membrane sections, for example by a foamed adhesive.

Brief Description of the Drawings [0013] Specific embodiments of the invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which: [0014] Figure 1 shows an upper element and an upper membrane part propped against the ceiling of a vault; [0015] Figure 2 shows a stage in the formation of a structure; and [0016] Figure 3 shows a completed structure, with an initial plasterboard section. Detailed Description of Particular Embodiments [0017] Figure 1 shows a vault of the kind often constructed underground in former times, having a vertical side walls 50 and end walls 52 and an arched ceiling 54, formed from stone or brick. As a preliminary step, a lower damp proof membrane (not visible) has been laid on the floor of the vault. The lower membrane is of a suitable polymeric material such as high density polyethylene (HDPE). In this example, the lower membrane is DELTA® MS20 from Delta Membrane Systems, a heavy gauge membrane comprising frustoconical dimples with a height of approx. 20 mm. Measures are taken to protect the perimeter of the floor. In this example, one or more strips of a further polymeric membrane 3, such as DELTA® MS-500, a medium gauge dimpled HDPE material, provides an upstand around the perimeter and is sealed to the lower membrane using a strong tape such as butyl rubber sealing tape 4. A screed 5 or a floating floor is then laid over the lower membrane.

[0018] The next stages of the method involve placing a further waterproof membrane against the ceiling 54 and the walls 50, 52, and constructing a framework to hold this membrane in place. A convenient material for the framework is plywood, but it is also possible to use other wooden, wood-based, metallic or plastics materials.

[0019] A ceiling membrane 6, here of DELTA ® MS-500 is cut to fit at least a central part of the ceiling 54 of the vault. If necessary, the ceiling membrane 6 is assembled by taping more than one membrane part together.

[0020] An upper frame element 7, best seen in Figure 2, has a length equal to the length of the vault. In this example, the upper element 7 comprises a wide upper strip 8, attached to a narrow lower strip 9 to provide a rebate 10 at the junction of the strips 8, 9. Both strips 8, 9 can be formed from 9 mm thick plywood, and the strips 8, 9 can have widths of 200 mm and 100 mm respectively.

[0021] Temporary props 11 are used to prop the upper element 7 in place along the apex of the ceiling 54, trapping the ceiling membrane 6 in place between the upper element 7 and the ceiling 54.

[0022] In some vaults, the ceiling membrane may be large enough to cover the walls of the vault as well as the ceiling. In the example shown here, however, additional side membrane parts 12 and end membrane parts 13 are required. Upper edges of the membrane parts 12, 13 are taped to the ceiling membrane 6, vertical edges of the parts 12,13 are taped to adjacent such parts, and lower edges of the parts 12,13 are taped behind the upstand 3. In all cases, joined membrane parts have a sufficient overlap to ensure a waterproof seal.

[0023] A lower retaining strip 14, e.g. of plywood, which can be placed along the lower edges of the walls 50 and/ or 52. Partially-curved frame members 15 are then installed, to retain the side membrane parts 12 against the side walls 50. In one example, the frame members may be spaced 400 mm apart center-to-center.

[0024] In this example, each curved member 15 is formed from overlapping layers of plywood, each layer being formed from more than one strip as necessary. The outermost layer can be installed first, terminating in the rebate 10 and braced against the floor 5. In the example shown in Figure 2, two further layers are then attached, e.g. by gluing and/or screwing, to the outermost layer, these further layers extending across the upper element 7. All three layers may be of 9 mm thick plywood. In wider vaults, at least the outermost layer may be thicker than this, e.g. 12 mm, whilst in smaller vaults and arched doorways, four layers in total may be used, e.g. 6 mm thick, to allow for the tighter curves.

[0025] After installation of the curved frame members 15, the temporary props 11 are removed. At this point the framework is self-supporting, despite not being attached to the walls 50, 52 or the ceiling 54.

[0026] As shown in Figure 3, end studwork 16 is installed at the ends of the framework. Also, in this wider part of the vault, side studwork 17 supports horizontal rails 18, which brace additional curved members 19 against the upper element 7.

[0027] Fixer foam 20 is placed on a rear side of the studwork 16,17, fixing the side and end membrane parts 12,13 to the studs so as to take their weight off the tape holding them to the ceiling membrane 6.

[0028] Services, such as pipes and electric wires 21 can be arranged behind the studs and/or curved members. Figure 3 also shows an initial section of plasterboard 22. The framework is completed by plasterboard, screwed, nailed and/or glued to the elements 7 and 15 to 19, to form a smooth plasterboard surface covering the walls 50, 52 and the ceiling 54 in their entirety, the framework being completely hidden. This surface can then be skimmed or covered with a faux stone-effect sheet to give an appearance similar to the original stone vault.

[0029] The invention thus provides a waterproof lining for a vault, securely held against the vault surfaces, which may be porous, without any mechanical fixing to those surfaces.

[0030] Modifications may be made to the specific embodiments described above without departing from the scope of the invention as set out in the claims. For example, the lower retaining strips may be formed with a rebate, the lower ends of the partially-curved frame members being braced against this rebate instead of the vault floor.

Claims (24)

1. A method of damp proofing a vault, comprising: arranging a waterproof membrane adjacent an internal surface of the vault; and forming a structure comprising mutually spaced elongate elements to retain the membrane between the internal surface and the structure.

2. A method according to claim 1, wherein the structure has a shape essentially mimicking that of the vault.

3. A method according to claim 1 or 2, wherein the elongate elements comprise wooden or wood-based strips or planks.

4. A method according to claim 3, wherein the elements comprise strips of plywood.

5. A method according to any preceding claim, wherein the elements are flexible, and are curved to follow an arched or domed surface of the vault.

6. A method according to claim 5, wherein after installation, the curved elements include straight, vertical portions.

7. A method according to claim 5 or 6, wherein the curved elements are braced against at least one of a floor of the vault, the internal surface of the vault, or a horizontal rail of the structure.

8. A method according to any preceding claim, wherein the step of arranging the membrane adjacent the surface includes the use of one or more adjustable props braced from the floor, to retain at least an upper part of the membrane against an upper surface of the vault.

9. A method according to claim 8, wherein an upper elongate element is placed between the prop(s) and the upper surface.

10. A method according to any preceding claim, wherein the vault has a generally constant arched cross-section, and an upper element or the upper element comprises a generally straight strip, extending along the apex of the arched upper surface.

11. A method according to claim 10, wherein the upper element is formed with parallel rebates for receiving curved elements.

12. A method according to any preceding claim, wherein an upper part of the membrane or the upper part of the membrane is retained against the upper surface of the vault, and subsequently, additional membrane sections for covering vertical surface of the vault are attached to the upper part.

13. A method according to any preceding claim, wherein formation of the structure includes the formation of vertical parts to fit vertical walls of the vault, and to retain vertical parts of the membrane.

12. A method according to any preceding claim, wherein elements of the structure are joined together by gluing and/ or screwing.

13. A method according to any preceding claim, comprising a preliminary step of laying a waterproof floor membrane on a floor of the vault.

14. A method according to claim 13, wherein an upstanding membrane is attached to the floor membrane around lowermost parts of the internal surface, and the waterproof membrane arranged adjacent the internal surface is taped or otherwise joined to the upstanding membrane.

15. A method according to claim 13 or 14, comprising laying a suitable floor may on top of the floor membrane.

16. A method according to any preceding claim, wherein, after the structure has been formed, additional studwork is inserted between vertical ones of the elements.

17. A method according to claims 12 and 16, comprising bonding the studwork to the additional membrane sections.

18. A method according to any preceding claim, wherein, after the structure has been formed, plasterboard is attached thereto to form a smooth wall.

19. Apparatus for damp proofing a vault, the apparatus comprising a structure including mutually spaced, elongate elements arranged adjacent an internal surface of the vault, and a waterproof membrane retained against the internal surface by said structure.

20. Apparatus according to claim 19, for use in a vault having a generally constant arched cross-section, wherein an upper element of the structure comprises a generally straight strip, extending along the apex of the arched upper surface.

21. Apparatus according to claim 20, wherein the upper element comprises parallel rebates receiving curved elongate elements.

22. Apparatus according to claim 19, 20 or 21, wherein the membrane comprises overlapping membrane sections, joined to each other by tape.

23. Apparatus according to any one of claims 19 to 22, wherein the structure comprises additional vertical studwork elements, bonded to vertical ones of the membrane sections.

24. Apparatus for damp proofing a vault, substantially as described herein with respect to the accompanying drawings.