GB2042605A - Method of Damping-Proofing Masonry Structures - Google Patents

Abstract

A method of adapting a masonry structure (1) for a damp-proofing or rot-proofing treatment, which method comprises boring a set of blind holes (2) into the structure (1) at intervals along a course that intercepts the assumed pathway of dampness into the structure (1), laying along said course a pipe manifold (3, 5, 11) having branch spigots (4) spaced apart along its length, each spigot being adapted to enter a corresponding blind hole in the structure, positioning each spigot in the mouth of a respective blind hole, and sealing the mouth of the hole around the shank of the spigot. The pipe manifold preferably comprises a plurality of hard plastics T-pieces (3) connected together in series by lengths of soft plastics tubing (11) which unite the arms (5) of the T- pieces, the legs (4) of the T-pieces serving as the branch spigots. <IMAGE>

Description

SPECIFICATION Method of Damp-proofing Masonry Structures This invention relates to damp-proofing and rot-proofing masonry structures, such as the walls of buildings. Many older buildings were constructed without damp-proof courses. In buildings which have them, damp-proof courses sometimes fail. It is known to strip the plaster from a damp wall, bore a series of holes deep into the wall at about skirting height, inject a treatment fluid into each hole under pressure, and replaster the wall. This method is vulnerable to fluid losses around the mouth of each hole, since the injecting nozzle does not fit perfectly.

Furthermore, if treatment proves ineffective, one is faced with the major job of stripping the plaster a second time, perhaps boring new holes, if the old ones cannot be found, and replastering afterwards.

It is an object of the invention to provide a method of damp-proofing and rot-proofing masonry structures which is free from the above recited disadvantages, and posesses further advantages as will appear from what follows.

The invention accordingly provides a method of adapting a masonry structure for a damp-proofing or rot-proofing treatment, which method comprises boring a set of blind holes into the structure at intervals along a course that intercepts the assumed pathway of dampness into the structure, laying along said course a pipe manifold having branch spigots spaced apart along its length, each spigot being adapted to enter a corresponding blind hole in the structure, positioning each spigot in the mouth of a respective blind hole, and sealing the mouth of the hole around the shank of the spigot.

The invention also provides a method of dampproofing or rot-proofing a masonry structure, which comprises feeding a liquid damp-proofing or rot-proofing agent through the manifold into the holes in a mansonry structure adapted for such treatment by the method set out above. The liquid damp-proofing or rot-proofing agent is selected from those chemical compositions known for that purpose. Compositions known for damp-proofing, for example, include compositions containing a silicone or silicones, and compositions containing a stearate or stearates.

The pipe manifold is conveniently made from hard plastics T-pieces connected together in series by lengths of soft plastics tubing. The tubing unites the arms of the T-pieces into a continuous run. The legs of the T-pieces serve as the branch spigots mentioned above.

The pipe manifold may alternatively be constructed from hard plastics T-pieces adapted for mutual engagement without the use of connecting tubing between them. In this embodiment the T-pieces have one arm terminating in a socket, the other in a matching spigot, whereby the arms of adjacent T-pieces can interlock in a liquid-tight push fit to form a continuous run, while the legs of the T-pieces serve, again, as the branch spigots mentioned above. In this embodiment also the arms of each T-piece are preferably of unequal length.

If the liquid damp-proofing or rot-proofing agent is to be fed into one end of the manifold, the other end is of course stopped.

The mouth of the hole is sealed around the shank of the spigot for preference by the application of a small quantity of quick-setting cement, mortar or plaster. This can be done manually with a trowel. The seal must not block the spigot. The spigot (e.g. the leg of a T-piece) may be provided with an external circumferential rib, flange or fin at or adjacent the free end thereof, for positive location of the spigot in the mouth of the hole by engagement of said rib, flange or fin with the walls of the hole. This provision has the additional advantage that the rib, flange or fin in situ in the hole provides a foundation or backing for the quick-setting cement, mortar or plaster, which facilitates the application thereof, and prevents it from penetrating so far into the hole as to run the risk of blocking the spigot.

In another preferred embodiment a separate socket element is sealed into the mouth of the hole, using a suitable sealing composition, such as a bitumen composition or quick-setting cement, mortar or plaster. The socket is adapted to receive a branch spigot as a liquid-tight push fit. The outer aspect of the socket in use may include an external flange around the mouth thereof, to predetermine the depth of penetration of the socket into the hole. The inner part of the socket in use must provide communication for fluid flow between the inserted branch spigot and the interior of the blind hole in the masonry, that is to say it must have at least one hole in the wall or the end thereof. A plurality of holes is preferred, so as to reduce the likelihood of the sockets becoming blocked by intruding debris from the drilled masonry.

Since pre-existing plaster is routinely removed from a masonry structure prior to carrying out a damp-proofing or rot-proofing procedure, and the proofed structure is afterwards replastered, it is preferred that the pipe manifold be buried in the new plaster, apart from an end or ends to which access is required for the introduction of the liquid damp-proofing or rot-proofing agent. Such end or ends can be accommodated in one or more terminal or access boxes mounted on the structure or (preferably) recessed thereinto. A terminal box advantageously incorporates a pipe bend, such as a 900 elbow piece mounted therein, having a socket for receiving liquid fed thereinto, and a spigot adapted to engage with an end of the pipe manifold.

The invention will be understood in greater detail from the following description of a particular embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which Fig. 1 is a horizontal section taken through the base of a masonry wall adapted for dampproofing treatment; Fig. 2 is a perspective view of a portion of the manifold shown in Fig. 1, to an enlarged scale; Fig. 3 is an access box for use with the manifold of Fig. 2; Fig. 4 is a section similar to that of Fig. 1 according to a second embodiment of the invention; Fig. 5 is a plan view of a portion of the manifold shown in Fig. 4; and Fig. 6 shows a socket member in (a) front elevation; (b) side elevation, (c) rear elevation and (d) longitudinal section.

Referring now to the drawings, and in particular to Figs. 1 to 3, a masonry wall 1 in need of damp-proofing is bored at intervals along a horizontal course near its base, to yield a set of blind holes 2 penetrating to about three-quarters of its thickness.

Into the mouth of each hole, the leg 4 of a hard plastics tubular T-piece 3 is inserted, the arms 5 being disposed substantially horizontally so as to line up with the arms of adjacent T-pieces in adjacent holes. Each T-piece 3 is moulded with a relatively flexible fin 6 around the leg 4 towards the free end thereof. The fin 6 is deformed by the walls of the hole 2 to locate the T-piece therein, and to form a barrier 7 defining an outer annular region 8 of the hole surrounding the inserted leg 4. The region 8 is sealed with a quick-setting cement composition, applied with a small or painting trowel, to form a solid plug 9 when set, thus firmly locating the T-piece 3.

The arms 5 of the T-piece terminate in hose nipple portions 10. Lengths of soft plastics tubing 11 are cut to fit between adjacent T-pieces 3 in the wall and to receive a respective hose nipple 10 in either end. One end of the resulting manifold is stopped off or plugged, the other end is connected to a terminal or access box 12, similar to an electrical junction box and similarly recessed into the wall so as to present an opening flush with the plaster which will be applied to the wall later.The terminal or access box 1 2 is provided with a hard plastics piping elbow junction piece 1 3, one limb 14 of which presents an access orifice 1 5 and is perpendicular to the face of the wall 1 in use, the other limb 1 6 projecting through a perforation 1 7 in a side wall of the box 12 to link up with the manifold through a further length of soft plastics tubing 11. Both limbs 14, 1 6 terminate in hose nipple portions 10.

The elbow piece 13 is fixed to the back or base of the box 12 for rigidity in use.

Referring now particularly to Figs. 4-6, a masonry wall 1 in need of damp-proofing is bored with a first hole 2a penetrating to about threequarters of its thickness. A socket member 1 8 having a flange 19 around its main orifice 20 is smeared with sealing composition around its neck region where it has circumferential fins 21 and inserted into the hole 2a until the flange 1 9 abuts on the face of the wall 1, and the sealing somposition is allowed to set while work proceeds.

Centered on a piug temporarily inserted in the socket member 18, an arc of predetermined radius R is scribed on the wall surface to provide a locus for boring a second hole 2b. The hole 2b is similarly plugged with a second socket member 18, providing a centre for a further scribed arc to ocate a further hole 2c, and so on. The hole may ve bored anywhere on the arc; thus it may be necessary, in walls of hard stone, to choose a point where the arc intersects a joint in the masonry, and bore the hole there, since hard stone is usually impermeable to moisture and the iamp-proofing is confined in practice to the mortar between the stones. The resulting line of isles accordingly does not necessarily follow a inear course, but may be a zig-zag.It is important however that adjacent holes are spaced apart by the distance R aforementioned, for a reason which will appear.

A hard plastics T-piece 23 is of asymmetrical design, having a long arm 24 and a short arm 25, terminating in a spigot 26 and a matching socket 27 respectively. The spigot and socket are jointing members enabling a plurality of T-pieces 23 to be assembled into a manifold, in which manifold the legs 22 of the T-pieces comprise the branch spigots 22. The spigot and socket 26, 27 are gently tapered and afford a fluid-tight push fit. In the manifold adjacent branch spigots 22 are spaced apart by the distance R aforementioned.

Each branch spigot 22 is inserted into a respective socket member 1 8 in which it, too, is a fluid-tight push fit, both branch spigot 22 and socket member 1 8 being tapered in matching fashion. The flexibility of the arms 24, 25 compensates for any non-linearity in the layout of the holes 2a, 2b etc.

One end of the manifold is stopped off or plugged, and the other end is connected to an access box similar to the one described above, except that the contained elbow piece terminates in a suitable jointing member (other than a hose nipple) for connection to the manifold.

The socket member 1 8 is pierced by slots 28 in its sides and end wall, to allow the treatment fluid to penetrate to the interior of the associated hole 2a, 2b etc. Its fins 21 heip to provide a grip in the mouth of the hole until the sealing composition has set.

Treatment fluid is pumped under pressure into the manifold via the elbow piece in the access box, in both embodiments described. Losses of treatment fluid are minimised since there is only one pump-to-manifold connection point.

Treatment can be repeated after a lapse of time, if it proves necessary, notwithstanding that the entire manifold (except the access box cover) is buried in a coat of plaster. The expense normally attending a repetition of a damp-proofing treatment is dramatically reduced, and the procedure therefor simplified almost to vanishing point. There is no need to depend on contractors guarantees, which have often tended to have a lifespan greater than that of the firm issuing them.

Slow feed of treatment fluid, including gravity feed without pumping, is feasible, and works well, because of the slow penetration of the treatment fluid into mortar and masonry, a factor that robs conventional pressure injection of much of its effectiveness.

It will be appreciated that the method of the invention can be applied to the damp-proofing of structures in which the dampness arises from lateral ground moisture penetration as well as structures in which it rises from the ground. A manifold can be applied to follow a vertically extending course as easily as a horizontal one.

This procedure is specially suitable for dampproofing partially or completely sub-ground basements. In such cases it may not be practicable to remove the external earth work, but whether it is practicable or not, the invention removes the necessity of doing it.

It will also be appreciated that the method of the invention can be applied to extended areas of masonry, by providing an extended network of manifolding instead of a manifold which follows a simple linear course. In such cases the manifold can be provided, for example, with connecting elements between one horizontal run and the next.

Claims (13)

Claims

1. A method of adapting a masonry structure for a damp-proofing or rot-proofing treatment, which method comprises boring a set of blind holes into the structure at intervals along a course that intercepts the assumed pathway of dampness into the structure, laying along said course a pipe manifold having branch spigots spaced apart along its length, each spigot being adapted to enter a corresponding blind hole in the structure, positioning each spigot in the mouth of a respective blind hole, and sealing the mouth of the hole around the shank of the spigot.

2. A method as claimed in claim 1 wherein the pipe manifold comprises a plurality of hard plastics T-pieces connected together in series by lengths of soft plastics tubing which unite the arms of the T-pieces, the legs of the T-pieces serving as the branch spigots.

3. A method as claimed in claim 1 wherein the pipe manifold comprises a plurality of hard plastics T-pieces adapted for mutual engagement by direct connection of each T-piece to the next, each T-piece having a first arm terminating in a socket, a second arm terminating in a matching spigot and a leg serving as a branch spigot, whereby the arms of adjacent T-pieces can interlock in a liquid-tight push fit to form a continuous run of manifold.

4. A method as claimed in claim 3 wherein the first arm of each T-piece differs in length from the second arm thereof.

5. A method as claimed in any of claims 1-4 wherein the spigot is provided with an external circumferential rib, flange or fin at or adjacent the free end thereof, for positive location of the spigot in the mouth of the hole by engagement of said rib, flange or fin with the walls of the hole.

6. A method as claimed in any of claims 1-5 wherein a separate socket element is sealed into the mouth of the hole, the socket being adapted to receive a branch spigot as a liquid-tight push fit.

7. A method as claimed in claim 6 wherein the socket is provided with an external circumferential flange at or adjacent the free end thereof for positive predetermination of the depth of penetration of the socket into the hole.

8. A method of damp-proofing or rot-proofing e masonry structure, which method comprises carrying out the method claimed in any of claims 1 to 7 on the structure, and then feeding a liquid damp-proofing or rot-proofing agent through the manifold into the holes in the masonry structure.

9. A method of damp-proofing or rot-proofing E masonry structure which has been adapted by a method as claimed in any of claims 1-7 which comprises feeding a liquid damp-proofing or rot proofing agent through the manifold into the holes in the masonry structure.

10. A method as claimed in claim 8 or 9 'wherein the agent comprises a silicone or silicones.

11. A method as claimed in claim 8 or 9 wherein the agent comprises a stearate or stearates.

12. A method as claimed in any of claims 1, 8 and 9, substantially as herein described with reference to or as illustrated in Figs. 1-3.

13. A method as claimed in any of claims 1, 8 and 9, substantially as herein described with reference to or as illustrated in Figs. 4-6.