GB1582653A - Method of impregnating masonry and other porous building materials with a course of damp coursing fluid - Google Patents

Description

(54) METHOD OF IMPREGNATING MASONRY AND OTHER POROUS BUILDING MATERIALS WITH A COURSE OF DAMP COURSING FLUID (71) We, REMTOX (CHEMICALS) LIMITED, of Howison Court, Gillingham, Dorset, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a method of impregnating masonry and other porous building materials with a course of damp coursing fluid.

At present there are two widely used methods of impregnating masonry with damp coursing fluid. In the gravity feed method bottles are placed in holes drilled at pre determined centres in the masonry. The bottles are of such a design that the holes are kept filled with the fluid, and the fluid is slowly absorbed into the masonry. Upon curing, e.g. by reaction with water or carbon dioxide, the active component in the fluid forms a water repelllent barrier. The other current method is similar to the first except that the fluid is injected under pressure into the drilled holes. This latter method is probably the more common.

Both of these known methods have dis advantages. With the gravity feed method the fluid is absorbed slowly by the masonry and the bottles usually have to be left in position overnight. As such it is necessary to make a return trip to remove the bottles, and moreover the exposed bottles are prone to vandalism. These particular disadvantages are not encountered with the pressure injection method, but on the other hand expensive injection equipment is needed. In addition injection often causes the fluid to be forced through fissures in the masonry, resulting in wastage.

The present invention provides a method of impregnating masonry or other porous building material with a course of damp coursing fluid wherein containers containing the fluid are inserted in to holes in the material and the fluid is then allowed to diffuse from the containers. The method requires neither gravity feed bottles nor pressure injection equipment, and usually only one visit to the site will be necessary.

The method provided by the invention can be used for inserting a new damp proof course in a wall or for making good an existing, failed damp proof course. Spacedapart holes are then drilled in the masonry and tubular containers inserted therein. The damp coursing fluid and the material of the containers will usually be selected such that seepage of the fluid occurs within one hour, preferaby within one-half hour of insertion. As such it is thus normally necessary to fill the containers on site immediately prior to insertion.

For most purposes the containers will themselves be' porous, and preferably of porous cardboard, more preferably of a cardboard which has not been filled or otherwise treated to render it water-resistant. A suitable container comprises a length of porous tube and two end-caps.

The damp coursing fluid may be one of the fluids used with the known methods, and is preferably either an aqueous sodium methyl siliconate solution or a solution in an organic solvent of a material based on aluminium stearate. These two particular fluids cure relatively slowly, the former by reaction with carbon dioxide and the latter by reaction with water. Less preferred fluids are those silicone-based materials which cure faster by reaction with water and which do not diffuse far before the onset of curing.

The pattern of the drilled holes, as well as the nature of the fluid and container, will depend principally on the type of porous building material being impregnated, and can be determined by trial drillings. For ordinary brickwork using 5% by weight aqueous sodium methyl siliconate in cardboard containers we find that acceptable results are obtained with holes of 25mm diameter at between 4+" and 6" centres. The holes are drilled to within '" of the opposite face of the brick, and may be horizontal or at an angle thereto, such as between 25 and 45 .

Each hole is then substantially filled with a container containing fluid, or, if the walls are thick and the containers short, with more than one such container. Particularly with horizontal holes it is desirable then to back fill each hole to present loss of fluid. Backfilling e.g. with waterproof cement coloured to match the brickwork or other masonry serves to seal in the containers and gives a neat finish.

While the present invention has been particularly described with reference to the use of 5% by weight aqueous sodium methyl siliconate in cardboard containers for impregnating brickwork, it can be varied. For example it is possible by trial and error to find materials and drilling patterns appropriate to concrete blocks, bath limestone and other porous building materials.

The containers need not be tubular, and may be of other materials. Indeed, by appropriate selection of the container material and damp coursing fluid it may not be necessary to use containers which are initially porous. For example, sodium methyl siliconate is strongly alkaline and will attack and dissolve certain metals such as aluminum. Thin aluminum containers after filling with the siliconate would give the same results as cardboard containers i.e.

controlled release of the fluid.

Moreover while the invention will ordinarily be used to insert a horizontal damp proof course in the walls of a house, it can be used to form other barriers. In particular, it can be used to insert damp proof courses which are vertical and/or in other walls or other constructions.

WHAT WE CLAIM IS: 1. A method of impregnating masonry or other porous building material with a course of damp coursing fluid wherein containers containing the fluid are inserted in to holes in the material and the fluid is then allowed to diffuse from the containers.

2. A method as claimed in Claim 1 wherein the fluid is a solution in an organic solvent of a material based on aluminium stearate.

3. A method as claimed in Claim 1 wherein the fluid is an aqueous sodium methyl siliconate solution.

4. A method as claimed in Claim 3 wherein the containers are of aluminium.

5. A method as claimed in any one of Claims 1 to 3 wherein the containers are themselves porous.

6. A method as claimed in Claim 5 wherein each container comprises a length of porous cardboard tube with end-caps.

7. A method as claimed in any one preceding claim wherein the holes are back filled after insertion of the containers.

8. A method of impregnating masonry or other porous building material with a course of damp coursing fluid, the method employing inserted containers and being substantially as hereinbefore described.

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

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. horizontal holes it is desirable then to back fill each hole to present loss of fluid. Backfilling e.g. with waterproof cement coloured to match the brickwork or other masonry serves to seal in the containers and gives a neat finish. While the present invention has been particularly described with reference to the use of 5% by weight aqueous sodium methyl siliconate in cardboard containers for impregnating brickwork, it can be varied. For example it is possible by trial and error to find materials and drilling patterns appropriate to concrete blocks, bath limestone and other porous building materials. The containers need not be tubular, and may be of other materials. Indeed, by appropriate selection of the container material and damp coursing fluid it may not be necessary to use containers which are initially porous. For example, sodium methyl siliconate is strongly alkaline and will attack and dissolve certain metals such as aluminum. Thin aluminum containers after filling with the siliconate would give the same results as cardboard containers i.e. controlled release of the fluid. Moreover while the invention will ordinarily be used to insert a horizontal damp proof course in the walls of a house, it can be used to form other barriers. In particular, it can be used to insert damp proof courses which are vertical and/or in other walls or other constructions. WHAT WE CLAIM IS:

1. A method of impregnating masonry or other porous building material with a course of damp coursing fluid wherein containers containing the fluid are inserted in to holes in the material and the fluid is then allowed to diffuse from the containers.

2. A method as claimed in Claim 1 wherein the fluid is a solution in an organic solvent of a material based on aluminium stearate.

3. A method as claimed in Claim 1 wherein the fluid is an aqueous sodium methyl siliconate solution.

4. A method as claimed in Claim 3 wherein the containers are of aluminium.

5. A method as claimed in any one of Claims 1 to 3 wherein the containers are themselves porous.

6. A method as claimed in Claim 5 wherein each container comprises a length of porous cardboard tube with end-caps.

7. A method as claimed in any one preceding claim wherein the holes are back filled after insertion of the containers.

8. A method of impregnating masonry or other porous building material with a course of damp coursing fluid, the method employing inserted containers and being substantially as hereinbefore described.