IE47089B1 - A method for the insulation of hollow walls by filling the space in between said walls - Google Patents

Abstract

The invention relates to a method and apparatus for filling a cavity wall with a heat insulating material. The insulating material is finely granulated flakes of mineral wool which are blown into the cavity through apertures through the mortar in one wall of the cavity wall. The wool flakes have a size of less than 25 mm and the apparatus is provided with means to distribute the flakes evenly within the cavity, such as a deflecting plate 15 of the nozzle 17. The nozzle may be of circular cross section and penetrate at the junction of horizontal and vertical mortar lines or may be rectangular penetrating through a vertical slot in the mortar.

Description

The invention relates to a method of insulating hollow cavity walls by filling the hollow space with an insulating material through an aperture in one wall of the cavity and by subsequently sealing off said aperture.

A method of this general type for the insulation of hollow walls is known.

In this known method small apertures are drilled in the wall, whereafter a liquid composition to be foamed is fed into said hollow space, and subsequently foamed, thereby forming the desired insulating material.

Said method presents the disadvantage that after some time some of the insulating properties of the plastics foam will be lost, due to shrinkage (θ of the plastics material and to moisture absorption.

It has also been proposed to insulate hollow walls by filling the hollow space with an inorganic insulating material in the form of mineral wool flakes. The latter method implies, however, that rather large parts (of the order of 6 cm diameter) have to be removed from the wall, and after the hollow space has been filled with mineral wool flakes, the large apertures have to be closed. Apart from the fact that the removal of such large parts - 2 4 7 08«? out of a wall structure involves much labour, such a method is psychologically unacceptable; when such large parts are removed from a wall, the owners of the house tend to think that their home is going to be damaged.

On the other hand, however, mineral wool flakes offer the advantage that they are not liable to a variety of influences like heat, cold, moisture, and the like, thus causing the insulating properties of the mineral wool flakes within the hollow walls to be very effective and to be unimpaired in time.

The present invention provides a method for the insulation of a hollow cavity wall, which comprises filling the cavity with an insulating material by blowing granulated flakes of mineral wool having a size of less than 25 mm into the cavity through at least one aperture in one brick built wall of the cavity wall and subsequently sealing off the or each said aperture, the or each said aperture through which the mineral wool flakes are blown being drilled in mortar coursing comprising joints between bricks of the brick built wall, the or each said aperture having a size of not more than 25 mm.

Preferably the or each aperture has a size of not more than about 20 mm.

For applying the method of the invention round apertures of e.g. 20 mm diameter may be drilled in the wall and subsequently the granulated mineral wool flakes may be introduced into the hollow cavity through the aperture(s). The application of such a round drilling aperture in the wall is not only more attractive from a psychological point of view, but much less labour expenditure is involved than in removing a brick from a wall.

This is illustrated by the fact that the removal of a brick, redisposal and the final pointing out of the joints with a trowel, requires a period of 10 min., whereas drilling a round aperture of 20 mm diameter, which is sealed off - 3 OS’? after filling the hollow cavity of the wall with insulating mineral wool flakes, only requires 1 minute.

From the above it will be clear that a considerable saving of time is obtained by applying the method according to the invention, even when two to four round apertures are required so as to obtain a good filling of the hollow wall instead of the removal of a brick.

As the drilling of the round hole is only effected in the joint region forming the point of intersection of a horizontal and a vertical joint, said apertures are almost exclusively drilled in the material of the joints and not in the bricks. This simplifies sealing off said aperture(s) by means of a jointing mortar.

The finally granulated mineral woolflakes preferably have a size of less than 25 mm, more preferably less than 20 mm. In particular mineral wool flakes having a size of less than 15 mm, such as 5 to 15 mm or less than 12 mm such as 8 to 12 mm, may be used.

In order to obtain a most effective insulation, the blown in granulated mineral wool flakes are expediently spread out when entering the hollow space. Owing to the latter spreading a very homogeneous layer of mineral wool flakes is produced which leads to optimum insulation.

Blowing the finely granulated mineral wool flakes into the cavity of the hollow wall is preferably performed by means of a pressurised gaseous fluid, preferably having an overpressure of 0.3 to 0.7 atmosphere, more particularly 0.5 atmosphere.

The method of the invention may comprise filling the space of a hollow wall by drilling out a vertical or a horizontal joint, so that a larger filling surface is obtained. The time required for drilling a vertical joint and - 4 47 0&Ϊ for sealing off said joint is 3 minutes. Said period therefore exceeds the period necessary for drilling round apertures, so that this method is less preferred.

The invention will now be illustrated with respect to an embodiment by means 5 of the accompanying drawings, wherein: Figure 1 shows schematically a cavity of a hollow wall, provided with a tube for supplying mineral wool with an outlet opening for spreading the material; Figure 2 shows an apparatus for blowing finely granulated mineral wool 10 flakes into the cavity of the hollow wall by means of an overpressure; Figure 3 shows a variant of a method of filling the cavity of a hollow wall by a supply tube having a slit-shaped outlet; Figure 4 shows a top view of the slit-shaped outlet as shown in Figure 3; and Figure 5 is a cross sectional view through a hollow wall with a supply tube in a further preferred embodiment.

Figures 1 and 5 show an outer wall 1 consisting of bricks which are united with each other by vertical joints 3 and horizontal joints 4.

A round aperture 5 having a diameter of about 20 mm is drilled in the jointing 20 material at the point where the vertical joint 3 and the horizontal joint 4 across each other. The diameter of the round aperture 5 may also be smaller than 20 mm, for example 10-15 mm. When such a type of aperture is drilled the bricks 2 are hardly damaged, since the width of the vertical and horizontal joints 3 and 4 is mostly such that the aperture can be drilled exactly in the jointing material of said joints which facilitates sealing off of said aperture 5 later on by means of mortar. - 5 4‘?oaw In order to fill cavity 6 of the hollow wall behind a layer of bricks 2, a supply tube 7 for supplying insulating material is slid through aperture 6, the diameter of said supply tube being about 16 mm.

So as to obtain effective spreading of the supplied finely granulated mineral 5 wool flakes within the cavity, it is preferred to accommodate the end of the supply tube flush with the surface of the bricks forming the inner wall of the space (see Figure 3).

According to another embodiment the end 8 of the supply tube is provided with a chamfer 9 at its free end, also causing the entering finely granulated mineral wool to be spread extremely well. It seems that better spreading is obtained if the free end of the supply tube for supplying the mineral wool material does not extend into the space between the walls.

Through a truncated conical transition 10 the tube 7 for supplying insulating material merges into a tube 11 having a larger diameter. In this case the tube 11 is a hose comprising an inlet 12 for insulating material and a gas inlet 13. Through gas inlet 13 gas is blown into the supply tube, whereby the finely granulated mineral wool flakes are entrained into the supply tube 7.

Finely granulated mineral wool flakes of a size of about 15 nm are used for forming the desired insulating layer 14 within the cavity 6 of the hollow wall. Preferably mineral woolflakes of a size of 8‘to 12 mm are used.

Pressurised gaseous fluid supplied through gas inlet 13, preferably having an overpressure of 0.3 to 0.7 atmosphere, conveys the finely granulated mineral wool flakes into the cavity space of the hollow wall. An over25 pressure of 0.5 atmosphere appears to give extremely good results. - 6 4-7 0 gq Figures 3 and 4 show a further embodiment of an apparatus for filling the cavity of a hollow wall. As can be seen expediently a larger filling surface is provided.

Through the longitudinal slit 15 which is formed by the longitudinal walls 16 5 and 16a and the sides 18 of the supply tube 17, insulating material is supplied; instead of a supply through the supply tube 7 having a rounded cross section, as shown in Figure 2. However, these slits are less preferred than the round apertures.

Said supply tube 17 also adjoins a hose 11, similar to the arrangement shown in Figure 2.

A longitudinal wall extension part 16c being an extension of the longitudinal wall 16a, extends towards the direction of the other longitudinal wall 16, the latter extension provides improved effective spreading of the insulating mineral wool flakes material in the cavity of the hollow wall. The longitudinal wall extension part 16 extends to beyond the free end 19 of the longitudinal wall 16, and forms triangular extension parts 18a and 18b, thus avoiding an accumulation of mineral wool flakes at the location of the blowing end.

When an aperture through which mineral wool flakes are blown into the cavity extends along a mortar course comprising a vertical and/or horizontal joint of the cavity wall, as illustrated in Figures 3 and 4, it will be understood that by a size of the aperture of not more than 25 mm there is meant the width of the aperture across the mortar coursing.

Claims (10)

1. A method for the insulation of a hollow cavity wall, which comprises filling the cavity with an insulating material by blowing granulated flakes of mineral wool having a size of less than 25 mm into the cavity through at least 5 one aperture in one brick built wall of the cavity wall and subsequently sealing off the or each said aperture, the or each said aperture through which the mineral wool flakes are blown being drilled in mortar coursing comprising joints between bricks of the brick built wall, the or each said aperture having a size of not more than 25 mm. 10

2. A method as claimed in Claim 1, wherein the or each said aperture has a size of not more than about 20 mm.

3. A method as claimed in Claim 2, wherein the size of the granulated mineral wool flakes is 5 to 15 mm.

4. A method as claimed in any foregoing claim, wherein the granulated 15 mineral wool flakes spread out, when entering the cavity.

5. A method as claimed in any foregoing claim, wherein the aperture(s) are rounded.

6. A method as claimed in any foregoing claim, wherein the or each aperture through which mineral wool flakes are blown into the cavity extends 20 along mortar coursing comprising a vertical and/or horizontal joint of the cavity wall.

7. A method as claimed in any foregoing claim, wherein the granulated flakes of mineral wool are blown into the cavity by means of a pressurised gaseous fluid having an overpressure of 0.3 to 0.7 atmosphere. -

8. 8. A method as claimed in any foregoing claim, wherein the mineral wool flakes are fed into the cavity by means of a supply pipe not extending into the cavity.

9. A method for the insulation of a hollow cavity wall, substantially as 5 herein described with reference to the accompanying drawings.

10. A wall insulated by the method of any of Claims 1 to 9.