EP0043120A1 - Method of restoring used or deformed floor surfaces particularly of wood, such as stair steps - Google Patents

Abstract

1. A method for refurbishing worn and/or deformed floor surfaces, particularly of wood, such as stair treads, by depositing a cold setting filler compound on the worn surface, characterized in that it comprises the following stages : - the surface to be treated is prepared by increasing its roughness, in particular by slightly lifting the fibres when the surface is made of wood ; - formwork (7) is placed round the free edges of the surface being treated, with one or more formwork sides (8, 8c) placed above the level of the least worn portions of the surface being treated so that the formwork is made suitably leaktight ; - the above-mentioned filler compound comprising a cold setting synthetic material and being sufficiently fluid to fill the formwork volume, is poured into the above-mentioned formwork and by gravity forms a free horizontal surface (14) and then can gel rapidly in no more than 5 to 10 minutes : - and then the formwork sides are removed.

Description

The present invention relates to a method of repairing worn or deformed ground surfaces, in particular wooden surfaces and for example stair treads. The method of the invention makes it possible to restore the floor surfaces and in particular the stair treads, to their original geometric shape by relining "in situ" without requiring the disassembly of the surface to be treated such as the treads old staircase.

The traditional repair of staircases, in new wood, whether it is total or that it only interests the nose of the step, as it is practiced in a conventional manner, is extremely expensive. Furthermore, when the structure of the staircase to be restored has played out as a result of a settlement, all the steps are poured out so that their replacement does not correct the defect in the staircase.

There are techniques borrowed from floor coverings such as vitrification, bonded plastics or the use of fitted profile stair noses as described for example in Belgian patent 551,387 or in German patent 1,683,405. Repair techniques are also known in which a mass can be used which can be applied and leveled with a spatula, for example based on epoxy resin reinforced by a profile placed on the stair nosing as described in German patent 1,659,941. All these film repair techniques, if they are effectively capable of restoring the aesthetics of an antiquated staircase by masking the flatness defects, do not however remedy the main defects and in particular the cant of an old staircase. In addition, these techniques are complex and require long-term intervention. Furthermore, such a coating of plastic material limited to a portion of the wooden stair step gives rise to variations affecting the flatness of the latter and the solidity of the wood-coating connection.

The object of the present invention is to solve all the problems linked to the repair of worn or deformed ground surfaces and in particular the repair of old wooden stair treads. The present invention overcomes the defect level or slope due to compaction of the struc- _tu re of stringers that appear over the length of the steps and across the latter. Flatness defects due to irregular and pronounced wear at the right of way are eliminated. In addition, damaged nosings are integrally redone with the same material that is used to re _- cover the entire surface to be treated. This surface is therefore covered with a homogeneous, resistant material which is one with the old worn step.

The method of the invention therefore resolves by a single operation all of the structural and aesthetic defects of the floor surfaces and in particular of the worn stairs.

• On prépare tout d'abord la surface à traiter en augmentant sa rugosité. Dans le cas d'une surface en bois et en particulier d'une marche d'escalier usée, ce traitement initial paut être fait de manière à soulever légèrement les fibres. Il peut être fait par rabotage grossier puis léger, en croisant les passages, au moyen d'une rape et d'une tronçon- _neuse à deux rangées de gouges convenablement émoussées pour éviter tout danger de découpe. Les fibres étant ainsi conve- nablcment soulevées ou en saillie, on améliore considérablement l'accrochage de la matière de rechargement.

The procedure for repairing worn and / or deformed floor surfaces, in particular wooden, such as in particular the stair treads, according to the invention, comprises the following sequence of steps:

• First of all, the surface to be treated is prepared by increasing its roughness. In the case of a wooden surface and in particular a worn stair step, this initial treatment can be done so as to slightly raise the fibers. It can be done by planing coarse and light, crossing the passes, by a rape and an honest tronçon- _No two rows of blunt cutters properly to avoid any danger of cutting. The fibers thus being properly lifted or protruding, the attachment of the filling material is considerably improved.

One or more formwork edges are then fitted around the free edges of the surface to be treated so that the upper edges are substantially in a horizontal plane and above the level of the most worn portions of the surface to be treated. The fixing of the formwork edges is also done so as to ensure a suitable seal to the formwork thus produced.

Then poured into the aforementioned formwork a filling composition comprising a curable synthetic material. At the time of pouring, the reloading composition is in a state of fluidity sufficient to completely fill the volume of the formwork and present by gravity a perfectly horizontal free surface. In this way, and thanks to the principle of fluid casting between formwork flanges, compensation is made automatically for any possible slope of the worn surface to be treated. The recharging composition is also capable of undergoing rapid gelation, in less than approximately 5 to 10 minutes and preferably in less than 5 minutes. In this way, the repair is done very quickly and any risk of settling of any charges contained in the reloading composition is avoided.

The formwork edges are then removed after a relatively short waiting time, the new surface being able to be opened to the movement of people very quickly in general after 1 hour.

In a first embodiment, the formwork flanges used are produced in the form of angles or flexible profiles having a flat or curved profile as appropriate. These profiles can be cut to the desired length. They can be made for example of synthetic plastic material which can be nailed such as polyvinyl chloride. These formwork edges are preferably fixed on at least a portion of the free edge of the surface to be treated in a zone below the level of said surface. In this case, the flanges have a profile deviating from the aforementioned lower zone so that the filling composition comes, at the time of casting, to wrap the free edge portion considered below the level of the surface to be treated. In the case of repair of stair treads, it is thus possible to wrap with the reloading composition, the stair nosing, so as to reconstitute it and to oppose any detachment effort thanks to the enveloping effect of the new stair nosing forming an integral part of the monolithic covering of the new step.

To promote the formwork, preferably applied before casting, on the projecting internal face of the formwork edges, a product reducing the adhesion with the gelled filling composition. It is possible, for example, to use soluble polyvinyl chloride, silicones or suitable waxes.

In a particularly interesting variant, the formwork flanges used comprise a semi-rigid and deformable adhesive strip. For example, plastic fabrics, plastics or laminated aluminum can be used. Such an adhesive strip is provisionally glued partially projecting around the free edges of the surface to be treated and can in certain cases, if necessary, be stiffened from the outside by means of a support profile by wooden example. The use of such adhesive strips makes it possible to further facilitate the production of the formwork by adapting it to any particular shape of the edges of the surface to be renovated.

As we have seen, one of the essential characteristics of the process of the invention is the use of a filling composition that is sufficiently liquid to be poured into a formwork with projecting edges in order to achieve automatic compensation for the slope and redo the flatness of the worn surface at the same time. To ensure proper pouring, it has been found that the reloading composition should preferably be maintained at the time of casting at a temperature of between 20 and 27 ° C. approximately depending on the ambient temperature at the time of casting and preferably between 22 and 27 ° C approx. In this way, the reloading composition has, during the casting, which lasts a few minutes, a viscosity which is of the order of 10 Poise at the start of the operation and does not exceed 100 Poise at the end of the casting so that automatic slope compensation is effectively obtained by means of a perfectly horizontal free surface before gelation.

The curable liquid recharging composition for carrying out the process of the invention comprises beforehand a synthetic resin which can be polymerized cold by the addition of a catalyst, loaded with glass fibers. These glass fibers are preferably cut and have a length of between 1 and 5 mm and preferably around 3 mm.

In most cases where it is desired to obtain a flame-retardant surface, the resurfacing composition also comprises mineral flame retardant fillers These fillers which usually have a density greater than the density of the resin in the liquid state at the time of casting, are used in combination with floating fillers with a density lower than the density of the resin. In this way, it is avoided that the settling which can occur during the short time interval between the start of the casting and the gelation does not lead to a migration of the charges unfavorable to the homogeneity of the cured composition.

As floating fillers, hollow microbeads of mineral material such as silica or alumina can be used, which also have the advantage of making it possible to nail the renovated surface obtained without causing the hardened material to burst. As floating charges, it is also possible to use aggregates of mineral or vegetable matter such as the corn rachis.

To improve the wear resistance of the renovated surface, it is possible to add to the reloading composition of the invention a particulate material such as glass beads with a diameter between approximately 0.4 and 1 mm.

Among the curable resins which can be used, mention may generally be made of catalyzed setting resins such as epoxy resins, polyurethanes and polyesters. It should be noted however that the epoxy resins exhibit slow hardening which can be a drawback for the process of the invention while the polyurethanes are not very compatible with wood which may still have a certain moisture content. On the other hand, polyester resins such as unsaturated liquid polyester have given excellent results in applications for repairing worn wooden stair treads.

• la fig. 1 montre la première étape d'un procédé de réfection de marches d'escalier usées en bois;
• la fig. 2 illustre la deuxième phase de l'étape de prépa- . ration de surfaces de la marche selon le procédé de l'invention;
• la fig. 3 est une vue en coupe schématique des gouges de la tronçonneuse utilisée dans l'étape illustrée sur la fig. 2;
• la fig. 4 montre la marche après installation des rebords de coffrage;
• la fig. 5 illustre l'étape de coulée de la composition de rechargement;
• les fig. 6 et 7montrent en coupe la marche après réfection;
• les fig. 8 et 9 montrent une variante dans laquelle une bande anti-dérapante a été.ultérieurement collée sur le bord extrême de la marche rénovée.

The invention will be better understood from the study of a few embodiments described by way of non-limiting example and illustrated in particular by the appended drawings, in which:

• fig. 1 shows the first step in a process for repairing worn wooden stair treads;
• fig. 2 illustrates the second phase of the preparation step. ration of walking surfaces according to the method of the invention;
• fig. 3 is a schematic sectional view of the gouges of the chainsaw used in the step illustrated in FIG. 2;
• fig. 4 shows the operation after installation of the formwork edges;
• fig. 5 illustrates the step of casting the reloading composition;
• fig. 6 and 7 show in section the step after repair;
• fig. 8 and 9 show a variant in which a non-slip strip has been subsequently bonded to the extreme edge of the renovated step.

In the embodiment illustrated in the figures, the method is suitable for repairing and treating the surface of stair treads made of hard wood, worn and the structure of which may have partially subsided over time . The wooden surface saturated with wax or encrusted with dust from step 1 is first prepared by means of a coarse planing then light executed using a hand rape 2 in the direction of the wood fibers, in this case, depending on the width of the step 1. Next, planing is carried out using a chainsaw 3 as can be seen in FIG. 2 this time in a direction overlapping with that of the wood, that is to say perpendicular to the previous operation. The chainsaw 3 is equipped with a double row of alternating gouges 4 and 5 as can be seen in FIG. 3. The two operations allow you to partially lift the fibers 6 on the surface thus creating a very rough peeled upper face subsequently allowing the material of the reloading composition to become one with the upper surface of the step. Thanks to this careful preparation of the upper surface of the step, an excellent attachment is indeed obtained, avoiding any risk of subsequent detachment.

After delimiting the area of the surface to be renovated, a formwork is formed all around the free edges of the step 1 consisting of several formwork edges 7 made of profiles made of flexible plastic material of polyvinyl chloride. These profiles are cut to the appropriate length and fixed by nailing on the one hand along the stair nosing for the formwork profile 8 and on the other hand on the side of the stringer for the formwork profile 9. The profile or flange of formwork 9 visible in FIG. 4 is flat and protrudes with respect to the prepared upper surface of the step 1. The profile 8 cooperating with the worn or deformed step nose 9 has a flat portion used for fixing by nailing on the lower step 8a and an outwardly curved profile portion 8b which is capable of reconstituting a new stair nosing. In this way, a suitable sealing formwork is formed, formed by the rim 9, the rim 8, the wall of the stairwell 10 and the riser 11, these last two surfaces playing the role of complementary part for the formwork.

The volume to be relined delimited by this formwork is then filled by gravity in a single pour as illustrated in fig. 5 where we see the container 12 containing the liquid filling composition which is poured all at once into the volume delimited by the formwork. It will be noted that the upper edges of the two formwork edges 8 and 9 are arranged so as to be substantially in a horizontal plane and of course above all above the level of the most worn portions of the upper surface of the step 1. The reloading composition 13 which is advantageously a cold-polymerizable synthetic resin added with a hardener immediately before pouring, is distributed inside the formwork by gravity, its free surface 14 becoming strictly horizontal given its viscosity similar to that of a liquid.

The ingredients of the composition as well as the maintenance of a suitable temperature of the order of 22 to 27 ° C. make it possible to carry out such a casting before gelation of the composition and to obtain gelation in a very rapid time as a general rule. less than 5 minutes, complete hardening being obtained after about 1 hour. Beyond this duration, it is possible to move again on the renovated step after formwork removal by removing the formwork edges 8 and 9, this operation being facilitated by the application on the internal face of said edges of formwork products which can be composed, for example, of emulsions of soluble polyvinyl chloride, of silicones or of waxes.

As can be seen in fig. 6 and 7, the renovated step is perfectly horizontal and the reloading material envelops the step nose over the entire length by means of a new step nose 15 which comes to hang under the initial step nose 9. This characteristic improves still the detachment resistance of the renovated monolithic coating.

The safety of the renovated step can be further improved by adding a deposit of non-slip material consisting of to the hardened reloading composition. for example by carborandum or solid glass beads, this material being applied by dusting and bonded with a resin of the same nature, pure and free of fillers. It is also possible, for the same purpose, to have in the vicinity of the edge of. walking an anti-slip adhesive strip 16.

• des fibres de verre coupées ou non, des microbilles de verre pleines, du carborandum pulvérulent ou granulé, des microbilles creuses composées de silice ou d alumine, des pigments susceptibles de conférer une coloration convenable à la surface rénovée et des agents d'ignifugation.

The compositions used in the present invention for carrying out the repair process require the preparation of a mixture comprising on the one hand a cold hardening resin such as a polyester added with a catalyst and a suitable accelerator, epoxy resin added with a hardener, a phenolic resin or a polyurethane resin with fillers chosen from one of the following fillers alone or as a mixture:

• cut or uncut glass fibers, solid glass microbeads, powdered or granulated carborandum, hollow microbeads composed of silica or alumina, pigments capable of imparting a suitable coloring to the renovated surface and flame retardants.

The use of flame retardants such as alumina hydrates and antimony trioxide supplemented with trichlorethyl phosphate present the difficulty that these fillers are of density much higher than those of the curable resins envisaged. To avoid any difficulty in settling during the casting operation and before gelling, provision is therefore made to add floating fillers to the composition, that is to say having a density lower than that of the resin. These fillers can be hollow microbeads, for example carbon ash microspheres having a density of 700 g / l, which is to be compared with the density of curable resins close to 1.1 kg / l. Such a composition can then be nailed, which allows the fixing, for example, of a carpet on the renovated stair treads, the loading material not likely to burst, taking into account the existence of hollow microbeads.

When it is not essential to provide for the possibility of nailing the final coating obtained, the hollow microbeads can be replaced by other floating charges comprising low density particulate materials such as for example corn aggregates obtained from corn spine recovery.

The composition is advantageously loaded by means of glass fibers which can be incorporated into the woven or non-woven strip coating or cut and incorporated into the mixture before casting. Glass fibers of short length cut to about 3 mm are preferably used, which substantially improve the mechanical strength of the hardened mixture.

The non-slip nature of the final surface obtained can be improved by incorporating into the mixture of solid glass beads of dimension between 0.4 and 1 mm, this addition further improving the wear resistance of the final surface.

Finally, the mixture can be colored in the mass with pigments reproducing the appearance of wood, stone or a usual coating placed for example on a staircase. One can at will incorporate other pigments such as luminescent or phosphorescent pigments in the mass or located at certain places on the surface.

Some non-limiting examples of compositions which can be used in the context of the process of the invention will be given below.

EXAMPLE 1

The following constituents are mixed in the proportions indicated:

The viscosity of this mixture is approximately 4 Poise.

After having suitably prepared by planing increasing the roughness, the surface of a stair tread of dimensions 1 mx 0.25 m worn in the center of 3 cm, two nailed edges are formed on the stair nosing and the edge of the stringer by a polyvinyl chloride profile. A non-stick product consisting of an emulsion of liquid polyvinyl chloride is applied to the internal surface of the profile.

10 g of catalyst and 10 g of accelerator are added to the mixture previously prepared and maintained at the temperature of 25 ° C. and immediately poured into the formwork thus prepared. The pouring takes place in a few minutes and the mixture is gelled after 5 minutes, the surface obtained being perfectly horizontal. One hour after the formwork edges can be easily removed and it is possible to move on the new surface of the renovated step. It will be noted that thanks to the choice of the sufficiently high temperature, the gelation takes place very quickly so that the various charges of the composition do not have time to migrate in the thickness of the coating before gelation.

EXAMPLE 2

For the renovation of a worn staircase including wooden steps we prepare the following mixture

The steps are prepared as in the previous example and an accelerator and a catalyst are added immediately before pouring for each individual step in proportions each time less than about 2%. The temperature of the composition before casting is maintained at around 23 ° C. Each individual casting operation takes approximately 2 minutes, complete gelation being noted after approximately 5 minutes. It is noted that the viscosity at the start of each casting is 10 Poise and that it does not exceed 100 Poise at the end of casting. The free surface after casting is perfectly horizontal.

We obtain a completely renovated surface that can be nailed thanks to the existence of hollow microbeads.

EXAMPLE 3

The same mixture is prepared as in Example 2, however replacing the hollow microbeads with corn aggregates of size 40 to 200 microns in the same proportions of 3 kg.

The coating obtained has excellent surface qualities, it is resistant to wear and its non-slip characteristics can be improved by bonding to the edge of the step, after hardening of a carborundum adhesive strip or by dusting, also after hardening; of carborundum grains in the vicinity of the edge of the step, these grains being bonded by means of pure resin and without fillers.

The method of the invention can be applied to the repair of worn wooden stairs that are encountered in most old buildings, whether residential or public use such as those of schools and administrative buildings such as stations, post offices, town halls, etc ...

It will also find interesting applications in wooden floor coverings such as damaged parquet floors or to protect against the action of water for example during the modernization of hotel rooms which can thus be fitted with a bathroom corner. Although the application of the process of the invention has been illustrated in examples of renovation of wooden stair treads, it will be understood that the process can be applied to the repair of larger surfaces, in particular of storey landings. Furthermore, the method can also be applied to the repair of stone or other material floor surfaces insofar as said material is relatively homogeneous from the heat point of view so as to ensure uniform gelling of the filling composition.

The implementation of the process of the invention can be carried out by an artisan applicator working alone who uses portable tools such as a light chainsaw, a grater, a jar of ready-to-use reloading material, jars of catalyst and accelerator, plastic profiles or adhesive tape for the production of formwork and portable heated mixer.

Claims (15)

1. A method of repairing worn and / or deformed floor surfaces, in particular of wood, such as in particular stair treads, characterized in that it comprises the following steps: - The surface to be treated is prepared by increasing its roughness, in particular by slightly lifting the fibers when the surface is made of wood; - one or more formwork edges are fitted around the free edges of the surface to be treated so that the upper edges are arranged above the level of the most worn portions of the surface to be treated and so as to ensure a suitable seal the formwork thus produced; - A filling composition is poured into the aforementioned formwork comprising a cold-hardenable synthetic material and which is, at the time of casting, in a state of fluidity sufficient to completely fill the volume of the formwork and present, by gravity, a free surface horizontal and capable of undergoing rapid gelation, preferably in less than about 5 to 10 minutes; - and the formwork edges are removed. 2. Method according to claim 1, characterized in that the formwork flanges used are made in the form of angles or flexible flexible profiles or of suitable profile, which can be cut to the desired length. 3. Method according to claim 1 or 2, characterized in that the formwork flanges used are made of synthetic plastic material which can be nailed such as polyvinyl chloride. 4. Method according to one of the preceding claims, characterized in that the formwork flanges are fixed on at least a free edge portion of the surface to be treated, in a zone below the level of said surface, the flanges moving away from said zone so that the reloading composition envelops the free edge portion considered below the level of the surface to be treated. 5. Method according to one of claims 2 to 5, characterized in that one applies before casting on the projecting internal face of the formwork edges, a product facilitating the formwork by reducing the adhesion with the gelled filling composition , such as soluble polyvinyl chloride, silicones or waxes. 6. Method according to claim 1, characterized in that the formwork edges used comprise a semi-rigid and deformable adhesive strip such as plastic sheeting, plastics and laminated aluminum, provisionally glued partially projecting around the free edges of the surface to be treated and optionally stiffened on the outside by a support profile. 7. Method according to one of the preceding claims, characterized in that the surface to be treated, when it is made of wood, is treated with a view to improving the bonding by coarse then light planing by crossing the passages by means of 'a grater and a chainsaw with two rows of gouges. 8. Method according to one of the preceding claims, characterized in that the recharging composition is maintained at the time of casting at a temperature between approximately 20 and 27 ° C and preferably between approximately 22 and 27 ° C . 9- Method according to one of the preceding claims, characterized in that one uses a filling composition having during the casting, a viscosity between 10 and 100 Poise approximately. 10. Method according to one of the preceding claims, characterized in that part of the treated surface is made non-slip by depositing or applying a pulverulent product after hardening, on the final surface. 11. curable liquid composition for recharging for the repair of surfaces for the implementation of the method according to one of the preceding claims, characterized in that it comprises a cold-polymerizable synthetic resin by addition of a catalyst, loaded with glass fibers of length between 1 and 5 mm and preferably about 3 mm. 12. Composition according to claim 11, characterized in that it also comprises mineral fire retardant fillers with a density greater than the density of the resin, in combination with floating fillers with a density less than the density of the resin. 13. Composition according to claim 12, characterized in that the floating fillers are hollow microbeads in mineral material such as silica and alumina or aggregates of mineral or vegetable materials such as the corn rachis. 14. Composition according to one of claims 11 to 13, characterized in that it further comprises solid glass beads of 0.4 to 1 mm in size approximately to improve the resistance to wear. 15. Composition according to one of claims 11 to 14, characterized in that the resin used is an unsaturated liquid polyester resin.

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