GB2105772A

GB2105772A - Damp proofing walls

Info

Publication number: GB2105772A
Application number: GB08127457A
Authority: GB
Inventors: Peter Treanor
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-09-11
Filing date: 1981-09-11
Publication date: 1983-03-30
Also published as: GB2105772B

Abstract

A method of inserting a damp-proof membrane in a wall comprising removing the mortar bed between courses of building elements to form an aperture of a length such that the structural stability of the wall or any dependent structure is not impaired, laying a damp-proof membrane 4 continuously in the aperture to overlie the lower course of the wall, inserting spacing elements in the aperture at suitable intervals to inhibit or prevent closing of the aperture and filling the aperture with mortar. <IMAGE>

Description

SPECIFICATION Improvements in or relating to the damp-proofing of walls A major problem in older buildings having no damp course is that of rising damp caused by differential capillary pressure in porous materials where the capillary water migrates from wet to dry areas.

Typically where a wall is subject to wet conditions in the ground and drying conditions above ground vertical movement of moisture is caused within the capillary pores of the wall material.

This is a known phenomenon and provisions for the elimination of the effects are provided in the design and construction of modern buildings. Such provisions include for example the use of nonporous material such as waterproof concrete, an impermeable barrier between the wet and dry zones such as damp proof material or the complete detachment of the wall from the source of wetness by means such as tanking.

There are however, many buildings which do not have any such provisions for the suppression of rising damp. Many methods are available to provide means for damp suppression within such buildings.

Most of these methods depend on making the transition zone between wet and dry areas impermeable to moisture. A completely effective method is to insert an impermeable membrane in this transition zone. A commonly used and often preferred method in the case of brick and block walls is to remove the mortar bedding between a line of bricks in the transition zone and replace it with such a membrane.

There are however, many difficulties in the executiion of this method, primarily due to the weight of the surrounding structure, and the need to prevent collapse or damage to a structure of which a wall to be treated may form a part. Conventional methods of re-packing the space created by removal of the mortar course with, for example, slate, do not restore completely the structural rigidity of the wall after completion. Additionally, it is very difficult and sometimes impossible to carry out such methods in thick walls or where only one side of the wall is accessible.

Another difficulty is that according to the known methods only small sections of a wall may be treated at a time before it is necessary to re-pack the joint where bedding has been removed, it is thus not possible to achieve a continuous process.

The invention provides in one of its aspects in the insertion of a dampproof membrane in a wall by cutting out a portion of a mortar course to provide an aperture and inserting the membrane into the aperture, the steps of inserting space elements at suitable intervals in the aperture to prevent or inhibit the closing of the aperture, and filling the aperture with mortar.

The invention provides in another of its aspects a method of providing a damp proof membrane in a wall comprising removing the mortar bed between courses of building elements to form an aperture of a length such that the structural stability of the wall or any dependent structure is not impaired, laying a damp proof membrane continuously in the aperture to overlie the lower course of the wall, inserting spacing elements in the aperture at suitable intervals to inhibit or prevent closing of the aperture and filling the aperture with mortar.

The spacing elements may optionally be removed before filling the aperture with mortar.

The mortar is preferably applied by a nozzle from a pressurised supply of uncured mortar.

The removal of mortar from a course is preferably carried out by means of a power saw having handles by which it may be guided from both sides of a wall if both sides are accessible.

The provision of spacing elements allows the method to be executed continuously, one or more first operatives removing mortar, second operative laying the damp proof membrane, third operative inserting spacing elements and fourth operative filling the aperture with mortar.

The spacing elements which may be slightly shorter than the width of the aperture (i.e. wall width) and are preferably of cross section having a first dimension less than the depth of the aperture and a second dimension equal to the depth of the aperture minus the thickness of the damp proof membrane. The spacing elements may thus be inserted in the aperture with the first dimension parallel to the depth of the aperture and pivoted to bring the second dimension bridging the space between the roof or the aperture and the damp proof membrane. Desirably the spacing elements are of rectangular cross section.

The invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a schematic three dimensional view of a part of a wall being treated according to the method of the invention; Figure 2 is a cross sectional view on line ll-ll of Figure 1 showing a mortaring nozzle about to apply mortar in an aperture in the wall; Figure 3 is a longitudinal cross-sectional view of a nozzle of the type shown in Figure 2; Figure 4 is a cross section on line IV-IV of Figure 3; Figure 5 is a schematic three-dimensional view of a spacing element being positioned in an aperture in the wail shown in Figure 1; and Figure 5A is a view similar to Figure 5 showing the spacing element having been turned through 90" to abut the roof of the aperture and also the dampproof membrane.

In the brick wall shown in Figure 1 a course of mortar has been removed to form an aperture along a line above a damp part 3 of the wall 1 to separate the damp part 3 from a dry part 2. Typically the damp part 3 will be in contact with a source of moisture, e.g., the ground, whilst dry part 2 will be above ground. A moisture impermeable membrane 4 is laid in the aperture overlying the damp part 3, i.e., the lower courses of bricks. Spacing elements as shown in Figures 5 and 5A are inserted at suitable intervals along the aperture. The spacing elements are of rectangular cross-section, the longer dimensiion D being substantially equal to the distance between the roof of the aperture and the membrane 4. Each spacing element is inserted into the aperture sideways as shown in Figure 5 and then twisted through an angle of 90" to fullfil its spacing function.

The interval between adjacent spacers is determined in known manner by the load on the wall and the materials from which it is made.

Leaving the spacing elements 6 in position the aperture is filled with cement mortar by means of a flattened tubular nozzle (see Figures 3 and 4). The mortar is cementitious mortar and is supplied from a reservoir under pressure in known manner. If necessary or desirable, any portion of the spacing elements protruding from the wall may be removed with a grinder before the mortar is supplied.

It is to be understood that any suitable mortar may be employed in the method of the invention and this need not necessarily be cementitious in nature.

The invention is applicable to mortar courses at any angle and not only horizontal mortar courses.

Any kind of modular block built wall may be modified according to the invention provided that it has removable lengths of straight course to enable rapid application of the method of the invention.

The spacers may be of any suitable shape.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features herein before referred to whether or not particular emphasis has been placed thereon.

CLAIMS (Filed on 20 Aug 1982) 1. In a method of inserting a damp-proof mem brane in a wall by cutting out a portion of a mortar course to provide an aperture and inserting the membrane into the aperture the steps of inserting spacing elements at suitable intervals in the aperture to prevent or inhibit the closing of the aperture, and filling the aperture with mortar.

2. A method of providing a damp-proof mem brane in a wall comprising removing the mortar bed between courses of building elements to form an aperture of a length such that the structural stability of the wall or any dependent structure is not impaired, laying a damp-proof membrane con tinuously in the aperture to overlie the lower course of the wall, inserting spacing elements in the aperture at suitable intervals to inhibit or prevent closing of the aperture and filling the aperture with mortar.

3. A method of providing a damp-proof mem brane in a wall as claimed in claim 2 in which the spacing elements are removed before filling the aperture with mortar.

4. A method of providing a damp-proof mem brane in a wall as claimed in claim 2 or claim 3 in which the mortar is applied by a nozzle from a pressurised supply of uncured mortar.

5. A method of providing a damp-proof mem brane in a wall as claimed in any of claims 2 to 4 in which removal of mortarfrom a course is preferably crried out by means of a power saw having handles by which it may be guided from both sides of a wall if both sides are accessible.

6. A method of providing a damp-proof membrane in a wall as claimed in any of claims 2 to 5 which is carried out continuously, one or more first operatives removing mortar, second operatives laying the damp-proof membrane, third operatives inserting spacing elements and fourth operatives filling the aperture with mortar.

7. A method of providing a damp-proof membrane in a wall as claimed in any of claims 2-6 in which the spacing elements are shorter than the width of the aperture are are of cross-section having a first dimension less than the depth of the aperture and a second dimension equal to the depth of the aperture minus the thickness of the damp-proof membrane.

8. A method of providing a damp-proof membrane in a wall as claimed in any of claims 2-7 in which the spacing elements are of rectangular cross-section.

9. A method of providing a damp-proof membrane in a wall as claimed in any of claims 2-8 in which the spacing elements are made of metal.

10. A method of providing a damp-proof membrane in a wall as claimed in claim 2 or any of claims 4-9 in which the spacing elements are not removed from the aperture in the wall and any portion of the spacing elements projecting from the walls is removed by a grinder before the mortar is supplied.

11. A method of providing a damp-proof membrane in a wall substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 4. Each spacing element is inserted into the aperture sideways as shown in Figure 5 and then twisted through an angle of 90" to fullfil its spacing function. The interval between adjacent spacers is determined in known manner by the load on the wall and the materials from which it is made. Leaving the spacing elements 6 in position the aperture is filled with cement mortar by means of a flattened tubular nozzle (see Figures 3 and 4). The mortar is cementitious mortar and is supplied from a reservoir under pressure in known manner. If necessary or desirable, any portion of the spacing elements protruding from the wall may be removed with a grinder before the mortar is supplied. It is to be understood that any suitable mortar may be employed in the method of the invention and this need not necessarily be cementitious in nature. The invention is applicable to mortar courses at any angle and not only horizontal mortar courses. Any kind of modular block built wall may be modified according to the invention provided that it has removable lengths of straight course to enable rapid application of the method of the invention. The spacers may be of any suitable shape. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features herein before referred to whether or not particular emphasis has been placed thereon. CLAIMS (Filed on 20 Aug 1982)

1. In a method of inserting a damp-proof mem brane in a wall by cutting out a portion of a mortar course to provide an aperture and inserting the membrane into the aperture the steps of inserting spacing elements at suitable intervals in the aperture to prevent or inhibit the closing of the aperture, and filling the aperture with mortar.