GB2124690A

GB2124690A - Damp proof course

Info

Publication number: GB2124690A
Application number: GB08303731A
Authority: GB
Inventors: Dommelen Dirk Johannes Van; Christopher John Greenup
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-09-14
Filing date: 1983-02-10
Publication date: 1984-02-22
Also published as: GB8303731D0; GB2124690B

Abstract

An elongate inflatable, sealable bag or envelope 1 is provided, fabricated from water impervious flexible film material, for insertion into a slot of a wall to form a new damp proof course. The bag or envelope comprises an elongate inflatable tubular body sealed at both ends, having valve means 5 therein to allow the bag or envelope to be filled under pressure with a quick setting waterproof material, the bag or envelope also having, at one or both ends thereof, flap or pocket 2 integral with or attached to the inflatable body thereof. Once the bag, together with a plurality of similar bags, has been inserted into a slot in a wall in an overlapping fashion, and the bags have been filled with the waterproof material, the bags and waterproof material provide a damp-proof course for the wall. <IMAGE>

Description

SPECIFICATION Sealable bags or envelopes for use in providing a damp-proof course This invention relates to elongate sealable bags or envelopes for use in providing a damp-proof course (DPC) in the walls of buildings, or the like, where DPC has not been provided, or the existing DPC has deteriorated or broken down and no longer provides a physical barrier to rising water.

A damp-proof course (DPC) is a physical barrier to water, which is usually inserted about 150 mm above natural ground level. The barrier is not necessarily horizontal as vertical DPC's are used to prevent the passage of water from adjoining structures.

Any dampness in building is unpleasant and unhealthy and rising damp is no exception. Affected areas are cold, decorations are damaged, moulds may grow and paper peels from the walls. Further, rising damp may cause floor timbers to become damp and to be attached by dry rot, which may spread to other timbers.

Bricks, stone and mortar, and similar materials, are porous and ground water carrying dissolved salts may rise many feet up a wall by capillary action unless preventative measures are taken. Generally, the finer the capillaries, the higher the water will rise against gravity.

In most houses built before the turn of the century, a DPC was not instailed during the construction stage. It is now compulsory to insert some form of DPC during construction and these can take the form of bitumen, epoxy composites, polythene, aluminium, copper or lead sheet, or slate or engineering bricks in cement mortar. However, in many buildings, the DPC has failed due to insufficient laying or deterioration with age; it may have cracked because of settlement or perished because of chemical reaction or beakdown.

Where DPC's have not been laid or have failed, rising damp can be remedied by inserting a new DPC into the affected walls as a physical barrier to the rising water. A DPC can be inserted in walls of existing buildings, and in the past this has been a slow, tedious and relatively expensive procedure.

According to known method, two or three adjacent bricks are removed from the damp effected wall along the line of the proposed new damp-proof course, a new membrane is then laid along the top of the exposed lower bricks and the bricks are then replaced, usually with new bricks because the process of removing the old bricks causes them to become severely damaged. As the new bricks are being replaced the mortar which is to be used to set the bricks into place and which is to fill up the spaces between the bricks must be applied lateraily instead of from the top of each brick as it is when the wall is being built. This means that the mortar invariably slips off the bricks as it is being manoevred into place with the result that the wall does have sufficient vertical support.This invariably results in most walls which have been treated in this manner, subsequently subsiding and causing cracks to appear and window frames or door frames to distort.

In the case of a wall of thickness greater than one brick the problem of applying the supporting mortar in such a manner as to ensure sufficient upward thrust is insurmountable. Pressure grouting of mortar has been attempted in the past in order to ensure that mortar covers the bricks throughout the entire thickness of the wall, but because the space between the new bricks form a slot which is open at the back, the incoming mortar from the pressure device has nothing against which it can build up in order then to commence thrusting upwards and thus providing the necessary support to the wall.

A further objection to the traditional method of installing a new DPC into an existing wall is the fact that it is a time consuming job not oniy because of the need to remove and relay bricks etc., but also the fact that the mortar must be allowed time to set before the next succeeding section of walling can be treated. It is also expensive and creates considerable upheaval in the home or building being treated. In more recent times saws have been used to cut a transverse slot along a line of mortar jointing and a new membrane has been inserted in the slot so formed. The same objections regarding the complete filling of the slot with mortar which will provide an immediate and positive upward thrust apply as described above.

The present invention provides an elongate sealable bag or envelope fabricated from water impervious flexible film material for insertion into a slot of a wall, the bag or envelope comprising an elongate inflatable tubular body sealed at both ends, having valve means therein to allow the bag or envelope to be filled under pressure with a quick setting waterproof material, the bag or envelope also having, at one or both ends thereof, a separate flap or pocket integral with or attached to the inflatable body thereof.

This invention sets out to provide not only a new DPC comprising two layers of waterproof material with a further layer of waterproof material sandwiched between, but more importantly a positive system of providing complete support for the wall above the new DPC so that there is vertical up-thrust almost immediately the new DPC is inserted. This will get over the previous problems in this regard.

Also, by using this method there will be virtually no mess caused in the building, there will be no subsiding of the treated walls, and the work will be completed in a significantly shorter time than by the present methods described above. And at far less labour cost than hitherto.

A specific embodiment of the invention will now be described by reference to the drawings, in which Figure 1 represents a plan view of an elongate bag according to an embodiment of the invention, illustrating the position of the end flaps or insertion pockets, and the filling valve; Figure2 is a side elevational view of the bag illustrated in Figure 1; Figure 3 is a perspective view of the bag illustrated in Figure 1; and Figure 4 is an illustration of several bags, in position as a DPC between two courses of bricks in a wall structure.

The DPC used in this embodiment of the invention comprises an elongate bag or envelope 1 of a width to suit the wall thickness and of a length to suit the length of a slot which has been cut transversally through the wall along the mortar course where the new DPC is to be inserted. The bag is manufactured in such a manner as to have included in its length two end pockets or flaps 2 suitable to be laid upon or under the adjacent end flap of the next succeeding bag (not illustrated) in order to provide a continuously waterproof layer on top of the lower brick course 4. Alternatively, the bags can be inserted into the slots cut into the wall, laid end to end without overlap, as shown at 3 in Figure 4, and the gaps inbetween infilled with a suitable waterproof mortar.

The bag consists of an impervious material such as polyethylene, or polyvinyl chloride (PVC), or the like, said bag being provided with means such as a non-return valve 5 for filling the bag with a quick setting waterproof material which is also capable of withstanding high compression loads. The bag with end pockets 2 is preferably formed by heat sealing of the bag material such that the separate compartments in the bag (two end pockets and central compartment inbetween) are formed by means of the seams so produced. The bag together with its filling material forms the new DPC comprising a layer of the set waterproof material sandwiched between two PVC film layers beween adjacent courses of bricks.If desired, the upper and lower surfaces of the bag may be coated with a suitable adhesive material which, when the bag is filled will be pressed hard against both upper and lower brick surfaces to provide additional adhesion and ensuring there will be no possibility of slipping between the layers of brickwork in the event of any future earth tremors or other vibrations. The quick-setting material may be any suitable material which is capable of withstanding high compressive loads. In some instances, depending upon client or official preferences, it may be a quick-setting epoxy mix, in other cases a quick-setting cement mortar mix containing water-proofing additives. In the case of epoxy mixes the filling valve also forms the mixing chamber wherein the two separate epoxies are mixed thoroughly prior to entering the bag.In either case the filling materials are injected under pressure from suitable pumps or pressure vessels.

The method of inserting the new DPC comprises cutting a horizontal slot transversally through the wall at the new DPC level, preferably for a distance of approximately 800 to 1000 mm. The two end pockets of each bag are preferably provided with push-rod insertion holes 6 in the same edge of the bag which houses the filling valve.

Suitable rods 7 are inserted through the holes 6 to facilitate insertion of the bag 1 into the pre-cut slot in the wall. The flaps 2 of adjacent bags 1 are either arranged in close juxtaposition or are made to overlap to provide a continuous layer. The bag at this stage would lie perfectly flat having had any inside air completely exhausted. The bag is then filled under suitable pressure either from a pump or pressure vessel with the waterproof material which has been selected.

The immediate effect of the bag being filled is to provide an upward thrust where it is most needed.

When the bag is completely full, the hardening process continues until the waterproof material has set solid and is immediately able to support the wall above thus enabling the operator to proceed to the next succeeding transverse cut along the new line of DPC.

The second and succeeding bags should be inserted in such a manner that adjacent end flaps are in close juxtaposition, or such that there is an effective overlapping of the flaps of adjacent bags.

After the whole length of wall has been treated the plastic valves can be cut off and if desired the exposed edges of the now inflated bags can be covered with a waterproof mortar to form a neat seam along the entire length of the new DPC. As a variation of this finishing off process, the bags can be manufactured to a slightly wider width than the wall which is to be treated and the extra width of bag be allowed to overhang the brickwork on each side of the wall. After the work has been completed the bags which are now filled with solid set mortar and which are overhanging the brickwork can be sheared off flush with the faces of the bricks to form a neat mortar seam. Any gaps between adjacent bags or between the bags and the wall can be filled with a suitable waterproof mortar. The slotting of the walls is preferably carried out by means of specially adapted chain saw equipped with diamond or carbide teeth suitable for cutting into masonry such as brick, cement blocks or stone or a newly developed ring saw. Either method of cutting may be provided with means of extracting dust or chipping to eliminate mess caused by the cutting process.

The invention is not restricted to the details of the foregoing embodiment.

Claims

1. An elongate sealable bag or envelope fabricated from water impervious flexible film material for insertion into a slot of a wall, the bag or envelope comprising an elongte inflatable tubular body sealed at both ends, having valve means therein to allow the bag or envelope to be filled under pressure with a quick setting waterproof material, the bag or envelope also having, at one or both ends thereof, a separate flap or pocket integral with or attached to the inflatable body thereof.

2. A bag or envelope as claimed in claim 1, wherein said valve means includes means to allow mixing of seperate components of a settable epoxy material with which the bag is to be filled.

3. A bag or envelope as claimed in claim 1 or claim 2, in which the flap or pocket is of sufficient proportions to overlap the end of another similar bag or envelope.

4. A bag or envelope as claimed in any one of claims 1 to 3, wherein said flap or pocket includes an opening for insertion of elongate means to facilitate insertion of said bag or envelope into a slot cut into a wall.

5. A bag or envelope as claimed in any one of the preceding claims, wherein said bag or envelope is fabricated from polyethylene PVC material.

6. An elongate sealable bag or envelope constructed and arranged substantially as herein described with reference to the accompanying drawings.

New claims or amendments to claims filed on 6th October 1983 Superseded claims 1 New or amended claims:

1. An elongate sealable bag or envelope fabricated from water impervious flexible film material for insertion into a slot of a wall, the bag or envelope comprising an elongate inflatable tubular body sealed at both ends, having valve means accessible from an elongate edge thereof, to allow the bag or envelope to be filled under pressure with a quick setting waterproof material after the bag or envelope has been inserted laterally into the slot, the bag or envelope also having, at one or both ends thereof, a flap or pocket integral with or attached to the inflatable body thereof, but separated from the interior of the bag or envelope so as not to be inflatable therewith.