GB2484543A

GB2484543A - Method for levelling timber floor cassettes and apparatus for levelled floor

Info

Publication number: GB2484543A
Application number: GB201017483A
Authority: GB
Inventors: Douglas Wilson Cullen
Original assignee: Intelligent Wood Systems Ltd
Current assignee: Intelligent Wood Systems Ltd
Priority date: 2010-10-15
Filing date: 2010-10-15
Publication date: 2012-04-18
Also published as: GB201017483D0

Abstract

The method comprises providing two floor cassettes 12, 14 each with respective outer joists 16a, 18a, and respective aligning means 32, 34 on the joists, locating the first cassette and then lowering the second cassette until the aligning means are aligned and then fixing the joists together. Preferably the aligning means is an aperture such as a slot. Once the aligning means are aligned an aligning member 36, such as a pin or bolt may be inserted through the adjacent apertures. The aligning member may be used to fix the joists together. Also claimed is a levelled floor 10 comprising floor cassettes wherein adjacent cassettes have outer joists which abut and are aligned and then an alignment member is inserted through the aligned means of both cassettes. The aligning member may be a pin with a flat upper surface and a tapered end. A floor cassette preferably comprises joists and decking 22, 24

Description

METHOD AND APPARATUS FOR

LEVELLING TIMBER FLOOR CASSETTES

The present invention relates to building construction and in particular, though not exclusively, to a method and apparatus for creating a level surface when constructing a floor from floor cassettes.

One traditional method of constructing floors in a building locates joists in or against the supporting walls. With the joists in place, lengths of timber i.e. floorboards are cut to length, positioned and nailed onto the joists. In order to achieve a level floor, skilled carpenters are required. Use of such skilled workers is expensive and costs to the build are further increased due to the on-site time required by the carpenters to complete each floor.

Developers are looking for ways to speed up the construction time and reduce the associated costs. In this regard, timber frame building systems have been developed. Within these systems the use of cassette floor panels is being adopted.

Floor cassettes are produced off-site in a factory and comprise ready assembled joists and floors. The joists are typically I joists or open web joists and the flooring is a decking of OSB boarding, plywood or chipboard. The cassettes are brought on site and lifted into position where the joists rest on a supporting wall or hanger, and adjacent cassettes are positioned side by side. Low skilled workers can then nail the abutting joists together at the edges of the cassettes and the floor is complete.

While obvious advantages are seen with the use of floor cassettes, the present Applicants' have become aware of a major disadvantage in their use. As the cassettes rest upon supporting walls or hangers and are installed by typically lower skilled workers, then the tolerances on the fitting of the cassettes is not high. As a result, it is guite common for adjacent cassettes to be mismatched such that a step' exits between the upper surfaces of the cassettes, once installed.

This lack of levelling is typically of the order of 3 to 5mm.

Those nailing the joists together from below will not notice the mismatch and consequently the floor is not corrected at the time of erection. If uncorrected, the problem becomes apparent when a floor covering e.g. linoleum, laminate, carpet or tiles, is laid across the cassettes. The mismatch in the heights of the cassettes prevents or at least spoils the appearance of the final finish.

When the floor is inspected and the fault identified, heavy duty sanders need to be brought in to sand out the step' and level up the floor. This is costly, time intensive and requires skilled labour, effectively negating the benefits of using floor cassettes. In addition, sanding reduces the depth of the decking compromising the sound and insulation performance of the floor cassette.

It is therefore an object of the present invention to provide a method and assembly for laying floor cassettes which levels adjacent floor cassettes and thereby obviates or at least mitigates the identified problem with current laying techniques.

According to a first aspect of the present invention there is provided a method of levelling floor cassettes, the method comprising the steps: (a) providing a first floor cassette, having a first outer joist including first aligning means at a predetermined distance from an upper surface of the cassette; (b) providing a second floor cassette, having a second outer joist including second aligning means at the predetermined distance from an upper surface of the cassette; (c) locating the first floor cassette in position and lowering the second floor cassette so that the second joist abuts the first joist in a side-by-side arrangement; (d) as the second floor cassette is lowered, bringing the aligning means into line with each other; and (e) fixing the joists together.

As the distance between the alignment means and the surface of the floor on each cassette is set and can be checked in the factory, by bringing the joists together at the alignment means, the floor will automatically be level across the adjacent cassettes.

Preferably, the method includes the step of inserting an aligning member through the first joist and into an aperture of the second joist. This assists in bringing the two joists into alignment.

Preferably also, the method includes the step of using the aligning member to hold the cassettes in alignment while fixing the joists together. Alternatively, the aligning member may also be the fixing member, thus a step may include inserting the aligning member and fixing the joists with the aligning member.

Preferably the method includes the step of bringing alignment means, spaced out along the joists, into alignment.

Advantageously, alignment means are brought together at the ends of the joists and at least one location egually spaced from the ends of the joists.

According to a second aspect of the present invention there is provided a levelled floor, the floor comprising: a first floor cassette, having a first outer joist including first aligning means at a predetermined distance from an upper surface of the cassette; a second floor cassette, having a second outer joist including second aligning means at the predetermined distance from an upper surface of the cassette; the first joist abutting the second joist in a side-by-side arrangement with the aligning means in line with each other; and fixing means to join the joists together once aligned.

As the distance between the alignment means and the surface of the floor on each cassette is set and can be checked in the factory, by fixing the joists together at the alignment means, the floor will automatically be level across the adjacent cassettes.

Preferably alignment means are arranged along a length of the joist. The alignment means may be arranged at either end of the joist and at one or more locations along the joist depending upon it's length. In this way, those fitting the cassettes need only monitor a few set positions along the joist as the second cassette is lowered beside the first cassette.

Preferably the alignment means comprises an aperture located through the joist, perpendicularly to it's length. In this way alignment of the joists can be done by sight, looking for a clear path through the adjacent joists.

Preferably the aperture is a slot. Such an arrangement provides an upper level surface which can act as a datum to ensure the distance between the upper level surface and the surface of the decking is fixed. Additionally the slot provides for lateral movement of the joists relative to each other to ease positioning and alignment.

More preferably, an aligning member is pushed through the apertures. The aligning member may be an elongate member.

This serves the dual purpose of bringing the joists into alignment and can be used as the fixing means.

In a preferred embodiment, the elongate member is a pin. More preferably, the pin has an upper surface which is planar to lie adjacent the upper level surface of the aperture. In this way, the joist is levelled on the pin. Preferably also, the pin has a tapered end. Such a tapered end allows easy initial location of the pin through the apertures. Advantageously, the pin has a head opposite the tapered end. The head provides a surface against which a hammer can be impacted to drive the pin into position. The head may also be used to grasp against, so that the pin may be removed once the joists are aligned.

Where the elongate member is a pin, the fixing means may be nails, located through the joists, when the pins are in place.

In this way, the pins can be removed and reused after the fixing means is in place.

In an alternative embodiment, the elongate member is a bolt.

Preferably the bolt has a head at a first end and a threaded spindle towards an opposing end. There may be a tapered section at the opposing end to assist in locating the bolt through the joists.

Preferably the joists are solid timber joists. Alternatively the joists may be I joists or open web joists as are known in the art.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which: Figure 1 is a schematic illustration of two adjacent floor cassettes prior to alignment; Figure 2 is a schematic illustration of the floor cassettes of Figure 1, in alignment according to the present invention; Figure 3 is a schematic illustration of two joists of adjacent floor cassettes, according to an embodiment of the present invention, prior to alignment; and Figure 4 is a cross-sectional view of an aligning member.

Referring initially to Figure 1 of the drawings there is a floor, generally indicated by reference numeral 10. Floor 10 includes two floor cassettes 12,14. Each cassette 12,14 includes joists l6a,b,18a,b. The joists 16,18 are of solid timber but could be of any type. Affixed to an upper surface of the joists 16,18 is a decking 20,22. Decking 20,22 is a sheet of OSE boarding, plywood or chipboard, which provides a surface 24,26 to the floor 10.

Joists 16a,18a are located at the edges 28,30 of the decking 20,22. Each joist 16a,18a has an aperture 32,34 arranged perpendicularly through it. The apertures 32,34 are located at a predetermined distance from the surfaces 28,30. This distance is precise as the cassettes 12,14 are produced in a factory where tolerances can be checked. The apertures 32,34 are slots having dimensions suitable to accommodate a bolt 36.

In use, the floor cassettes 12,14 will be assembled in a factory and brought on site with a load of cassettes. Each cassette will be systematically lifted into position with the joists 16,18 typically resting on hangers (not shown) which are already in the building. When a first cassette 12 is in position, the second cassette 14 is lowered beside it so that the cassettes sit side-by-side. Workers will be available situated under the cassettes 12,14 to ensure the joists 16a,18b are positioned as close together as possible.

In the present invention, as the second cassette 14 is brought alongside the first cassette 12, from above, a workman will look through aperture 32 and note when he sees light coming through aperture 34. At this time, a bolt 36, is located through aperture 32 and forced through aperture 34. The bolt 36 will therefore bring the apertures 32,34 into alignment.

Reference is now made to Figure 2 of the drawings which illustrates the floor 10, now in alignment. As can be seen the bolt 36 is located through the joists 16a,18a. A washer and nut 38 are fitted so that the joists 16a,18a are fixed together. Nails and other fittings can also be applied between the joists to assist in securing the cassettes 12,14 together.

With the bolt 36 in position, the surfaces 24,26 of the decking 20,22, are coplanar, providing a level surface to the floor 10. Additionally the edges 28,30 are brought together in alignment, so that there is no gap between the cassettes 12,14 at the joists 16a,18a.

A floor cassette 12,14 will typically have a number of apertures 32,36 arranged along the length of the outer joist l6a,l8a. In this way, each pair of apertures are used to level the entire surface 24,26 of each sheet of decking 20,22 with respect to the decking 22,20 of the adjacent cassette 14,12. In a preferred embodiment there will be apertures towards the ends of the joists 16a,18a and at the midpoint along the edge of the cassette. This should provide sufficient alignment to level the floor 10.

Reference is now made to Figure 3 of the drawings which illustrates two joists, 40,42 being brought into alignment in accordance with an embodiment of the present invention. Joists 40,42 each have an aperture 44,46 located therein. Each aperture 44,46 is in the form of a slot having rounded ends.

This provides an upper edge 48,50 to each slot. The edge 48,50 is used as a datum to provide a precise measurement between the slot and the upper surface 52,54 of each joist 40,42 respectively. It also provides a level surface against which the aligning member can rest. The slots allow for lateral movement without affecting the alignment. This lateral movement can help in positioning the cassettes where tolerance in the location of hangers is low. In a further embodiment the slot can have a tapered entrance to further assist in locating the aligning member through the aperture.

Reference is now made to Figure 4 of the drawings which illustrates an aligning member, generally indicated by reference numeral 60, suitable for use in the present invention. Aligning member 60 is in the form of a pin. The pin has an elongate body and may be of any cross-sectional shape in the vertical plane, but must include a planar upper surface 62 on the horizontal plane. The surface 62 will abut with the upper edges 48,50 of the slots and assist in providing levelling of the joists 40,42. At a first end 64 is a head 66, providing a face 68, perpendicular to the surface 62. The face 68 is of sufficient dimensions so that a hammer may be used to drive the member 60 through the slot in the second joist 42. Member 60 may require to be forced through the aperture of the second joist as the member may be taking the weight of the joist during alignment. To aid this, the distal end 70 of the member 60 is angled to provide a taper below the surface 62. Once the member 60 is located through both joists 40,42, nails and/or other fastenings are used to fix the joists together in their now aligned position. The member 60 can then be removed and re-used for alignment of other cassettes. A rear surface 72 is provided to the head 66 to assist in the removal of the member 60.

In a preferred embodiment the alignment member 60 is a pin having a body with a thickness of 12mm, tapering to 5mm at the distal end. The height of the slots in the joists is 12.2mm.

The principle advantage of the present invention is that it provides a method and apparatus for creating a level surface when constructing a floor from floor cassettes so that steps or mismatches are not present.

A further advantage of the present invention is that it provides a method and apparatus for creating a level surface when constructing a floor from floor cassettes which does not require skilled tradesmen.

A yet further advantage of the present invention is that it provides a method and apparatus for creating a level surfaoe when oonstructing a floor from floor cassettes which does not impede the thermal or acoustic performance of the floor.

It will be appreciated by those skilled in the art that modifications may be made to invention herein described without departing from the scope thereof. For example, the apertures and aligning members may be of any dimensions which allow the member to pass into the apertures.

Claims

CLAIMS1. A method of levelling floor cassettes, the method comprising the steps: (a) providing a first floor cassette, having a first outer joist including first aligning means at a predetermined distance from an upper surface of the cassette; (b) providing a second floor cassette, having a second outer joist including second aligning means at the predetermined distance from an upper surface of the cassette; (c) locating the first floor cassette in position and lowering the second floor cassette so that the second joist abuts the first joist in a side-by-side arrangement; r (d) as the second floor cassette is lowered, bringing 0 the aligning means into line with each other; and (e) fixing the joists together.
2. A method of levelling floor cassettes according to claim 1 wherein the method includes the step of inserting an aligning member through the first joist and into an aperture of the second joist.
3. A method of levelling floor cassettes according to claim 2 wherein the method includes the step of using the aligning member to hold the cassettes in alignment while fixing the joists together.
4. A method of levelling floor cassettes according to claim 2 wherein the aligning member is also the fixing member, and the method includes the step of inserting the aligning member and fixing the joists with the aligning member.
5. A method of levelling floor oassettes aooording to any preoeding claim wherein the method inoludes the step of bringing alignment means, spaoed out along the joists, into alignment.
6. A method of levelling floor oassettes aooording to olaim 5 wherein alignment means are brought together at the ends of the joists and at least one location egually spaced from the ends of the joists.
7. A levelled floor, the floor comprising: a first floor cassette, having a first outer joist including first aligning means at a predetermined distance from an upper r surface of the cassette; a second floor cassette, having 0 a second outer joist including second aligning means at the predetermined distance from an upper surface of the cassette; the first joist abutting the second joist in a r side-by-side arrangement with the aligning means in line with each other; and fixing means to join the joists together once aligned.
8. A levelled floor according to claim 7 wherein the alignment means are arranged along a length of each outer joist.
9. A levelled floor according to claim 8 wherein the alignment means are arranged at either end of the joist and at one or more locations along each outer joist.
10. A levelled floor according to any one of claims 7 to 9 wherein the alignment means comprises an aperture located through each outer joist, perpendicularly to the joists length.
11. A levelled floor according to claim 10 wherein the aperture is a slot.
12. A levelled floor according to claim 10 or claim 11 wherein an aligning member is pushed through the apertures.
13. A levelled floor according to claim 12 wherein the aligning member is an elongate member.
14. A levelled floor according to claim 13 wherein the elongate member is a pin.r
15. A levelled floor according to claim 14 wherein the pin 0 has an upper surface which is planar to lie adjacent the upper level surface of the aperture.
16. A levelled floor according to claim 14 or claim 15 wherein the pin has a tapered end.
17. A levelled floor according to claim 16 wherein the pin has a head opposite the tapered end.
18. A levelled fioor according to any one of claims 14 to 17 wherein the fixing means is nails, located through the joists, when the pins are in place.
19. A levelled floor according to claim 13 wherein the elongate member is a bolt having a head at a first end and a threaded spindle towards an opposing end.
20. A levelled floor aocording to claim 19 wherein the bolt has a tapered seotion at the opposing end to assist in locating the bolt through the joists.
21. A levelled floor according to any one of claims 7 to 20 wherein the joists are solid timber joists. r C) r