GB2444497A

GB2444497A - Positioning wall frames

Info

Publication number: GB2444497A
Application number: GB0624522A
Authority: GB
Inventors: John Window
Original assignee: Henley Consultants Ltd
Current assignee: HENLEY TECHNOLOGY LTD
Priority date: 2006-12-08
Filing date: 2006-12-08
Publication date: 2008-06-11
Also published as: GB0624522D0; WO2008068513A3; WO2008068513A2

Abstract

The invention provides a method of setting out and positioning wall frames of a modular building that is constructed from a number of prefabricated wall frames secured to one another or to upright columns to create a shell framework for the building. The method requires a cast slab concrete floor, prepared over a suitable foundation. Lines are marked on the floor corresponding to centre lines or offset centre lines for the wall frames, and over those lines are positioned rows of metal sole plates to be aligned, in the final building, with the wall frames. The sole plates can be accurately positioned by aligning angular cut-out portions of the sole plates with the lines marked on the floor, and while maintaining this accurate alignment the sole plates are bolted to the floor, using concrete bolts or concrete anchors 5. The wall frames 9 can then be accurately aligned with the sole plates 1 by bringing them into face-to-face abutment with upstanding flanges 29 of the sole plates.

Description

TITLE

Setting Out Wall Frames

DESCRIPTION

Field of the Invention

The invention relates to a method of setting out and positioning the wall frames of a modular building that is constructed from a plurality of pre-fabricated wall frames.

Background Art

In modern building construction it is known to assemble a building from a plurality of factory-formed modular wall frames, each fabricated from cold-formed structural steel. The steel is cold-formed into various profiles to create the necessary rigidity. One well documented profile is a so-called C-profile in which the sheet of steel is folded longitudinally to create a front face, two side faces each in a plane perpendicular to that of the front face, and two inturned flange portions down the longitudinal edges of the side faces remote from the front face. Cold-formed C-section structural steel members can be assembled, generally by bolting or welding together into wall frames which include some vertical members, some horizontal members and optionally one or more diagonal cross-brace members. Each wall frame can be of a size and shape to suit the building being constructed, but is generally room- height and can be the length of the room. Four such wall frames can then be assembled on site to define the four walls of a rectangular room, with door and window openings already created as an integral part of the wall frame.

The assembly on site can involve the securing together of abutting wall frames, or the securing of the wall frames to upright columns, either constructional method creating a shelf framework for the building.

The on-site manoeuvring of the wall frames into their final positions requires a very high precision in the positioning of the individual wall frames. Each frame can be manufactured under factory conditions to a tolerance of as little as 0.1 mm, and a similar precision in the physical location of the individual wall frames before securing them together is necessary if the precision of the initial factory prefabrication methods are not to be compromised. That degree of precision is difficult to achieve, because the wall frames are large and heavy, and therefore unwieldy to manipulate to such a high standard of accuracy. Traditionally the individual wall frames have simply been manhandled into position on a cast concrete flooring slab until they abut a builders line stretched taught to mark out the intended position of the wall frame, and then supported in position for example by a temporary connection to a perpendicular wall frame and bolted to the floor slab using anchorage bolts drilled into the concrete of the floor slab. There is a great need for a rapid and accurate method of setting out and positioning the wall frames on either the ground floor or higher floors of a modular building, and this invention serves to fulfil that need.

and then supported in position for example by a temporary connection to a perpendicular wall frame and bolted to the floor slab using anchorage bolts drilled into the concrete of the floor slab. There is a great need for a rapid and accurate method of setting out and positioning the wall frames on either the ground floor or higher floors of a modular building, and this invention serves to fulfil that need.

The invention The invention provides the method of setting out and positioning identified in claim 1 herein. The sole plates used in the method of the invention are either generally flat metal plates with upstanding locating flanges at precise defined spacings, or L-section or U-section channel members incorporating similar upstanding flanges. An important feature of the sole plates is their angular cut-out portions. Preferably each sole plate is provided with at least one pair of V-shaped notches cut into the base portion of the sole plate at opposite ends thereof, and aligned with a longitudinal centre line of the sole plate or offset from that longitudinal centre line by a precisely measured predetermined distance. The sole plates can be laser-cut under computer control for optimum accuracy of location of the V-shaped notches. Additional angular cut-out portions of the sole plates can be provided, such as poles cut through the base portion of the sole plate and having an internal periphery which includes at least one V-shaped notch precisely aligned with an imaginary line connecting the apices of the pair of V-shaped notches at opposite ends of the sole plate. In addition to the V-shaped notches precisely aligned with a longitudinal centre line of the sole plate, the sole plate may also incorporate pairs of notches and optionally intermediate cut-out portions located at precisely calculated distances and spacings along the length of the sole plate.

The sole plates are much lighter in weight than the complete wall frames, and can therefore be positioned on a cast slab concrete floor with much greater precision than has been achieved in prior art methods which move the entire wall frame to achieve the initial precisioning.

The method of marking the line or lines on the cast slab concrete floor is also one that should be capable of great accuracy, to take maximum advantage of the accuracy of fabrication of the individual wall frames. Preferably each line is created by stretching a builders line or wire over the cast floor slab, and checking the accuracy and positioning of that wire or builders line very carefully to ensure that its location over the cast floor slab is the final degree of desired accuracy. Paint or a marker dye is then sprayed downwardly onto the floor over the wire, so that when the wire is taken up the shadow of the wire remains as a clearly marked line on the floor. A grid of such lines can be created, corresponding both to the centre lines of the ultimate walls of the building to be positioned on the floor slab, and to predefined positions of transverse lines which define the correct longitudinal position of the sole plates along those centre lines.

The individual sole plates are then placed over the marked lines on the floor slab, and carefully manipulated until they are in the precise position intended.

The sole plates can then be secured to the floor in those precise positions, for example by fixing bolts let into holes drilled in the concrete floor slab, with nuts of the fixing bolts clamping the sole plate firmly to the floor slab.

Preferably the fixing bolts pass through apertures formed in dimpled downwardly swaged mounting points formed in the sole plate, and if desired at this stage metal shims can be inserted between the sole plate and the cast floor, to build up one or more corners of the sole plate until it is on a true horizontal level.

If the sole plates that are used are generally flat metal plates without side flanges, then the method of invention can proceed directly to the installation of the wall frames. If, however, the sole plates are L-shaped or U-shaped in section, then the upstands along the longitudinal edges of those sole plates can be used to define a true edge and level for a screed surface that is spread over the cast floor slab before erection of the wall frames. Preferably a damp-proof membrane is spread across the floor slab between adjacent rows of sole plates, and the floor screed applied and levelled either by pouring it directly onto the damp-proof membrane or by pouring it over an insulating filler such as a flooring grade insulation board laid over the damp-proof membrane. Preferably the damp-proof membrane extends over the sides of the sole plates, in which case the sole plates themselves can be isolated from moisture rising through the concrete floor slab by means of a clear varnish or transparent moisture barrier film applied to the cast floor slab along the lines on which the wall frames will ultimately sit. The application of the floor screed greatly assists the anchorage of the sole plates in their final accurate locations on the floor slab, but an alternative way of stabilising the accurately predefined positions of the sole plates on the floor slab, suitable for flat sole plates as well as for those with longitudinal edge flanges, is to apply a resin grout to the sole plate after its first fixing, under conditions such at the resin grout passes through holes and slots in the sole plate, to bond directly to the concrete below.

The sole plates are now ready for the rapid and accurate location of the wall frames. Each wall frame can be manoeuvred into position over the corresponding row of sole plates, and accurately positioned relative to those sole plates by abutment with the upstanding flanges of the sole plates. This provides a positive location of the wall frames relative to the cast floor, and is achieved at minimal effort during the handling of the large and heavy wall frames. Metal upright columns which typically would be provided at an L-shaped junction between two wall frames can similarly be located by bringing them into face-to-face abutment with upstanding flanges of the sole plates.

Drawings In the drawings, Figure 1 is a perspective view of a sole plate for use in the method of the invention; Figure 2 is a vertical section through a floor showing a cast concrete floor slab, a layer of flooring grade insulation over that floor slab and a top screed, with the sole plate of Figure 1 secured to the floor slab and defining a channel in the finished floor into which a wall slab is located; Figure 2a is an enlarged detail of a central portion of Figure 2; Figure 3 is a plan view of a flat sole plate which is the same as the sole plate of Figure 1 except that it has no side flanges; Figure 4 is an enlarged detail of a cutting pattern used to create the upstanding flanges of the sole plates of Figures 1 and 3; and Figure 5 is a perspective view of a part of a sole plate showing the cut-out flange portion of Figure 4 bent upwardly into a vertical orientation.

Figures 1, 2 and 2a illustrate a generally U-shaped sole plate I for use in the method of the invention. The sole plate 1 comprises a ground-engaging base portion 2 and two longitudinally extending side flanges 3. The base portion 2 is formed with a number of V-shaped notches and cut-out portions precisely as illustrated in Figure 3, which are described in greater detail below. In essence, the sole plate 1 of Figure 1 is exactly the same as the sole plate Ia of Figure 3 except that it has the additional upstanding side flanges 3.

Figures 2 and 2a illustrate how, after securing the sole plate 1 to a cast slab concrete floor 4 using anchorage bolts 5, the space between adjacent sole plates 1 is filled by a layer of floor insulation 6 topped by a cement screed 7.

The bolts 5 are shown very schematically in Figures 2 and 2a as simple screws, but in fact expanding concrete bolts would normally be used, to create a secure and robust anchorage of the sole plate 1 to the cast floor 4.

Although not shown in Figures 2 and 2a, a damp-proof membrane would be provided over the top of the cast floor 4 and up the sides 3 of the sole plate I before laying the insulation 6 and the to screed 7, and a water proof varnish or similar damp-proof barrier would be applied to the floor slab 4 along the lines where the sole plates I are going to sit. If desired the channel formed by the sole plate 1 can be temporarily filled for example with a length of timber or with a metal end cap while the top screed 7 is applied, to prevent screed material from entering and filling the central channel in the sole plate 1 between the upstanding side flanges 3.

Figures 2 and 2a also show the location 8 of securing bolts which pass through the bottom rail of a wall frame 9 and into the floor slab 4 for the final fixing of the wall panel 9 to the floor.

The precise pattern of notches and apertures in the sole plate I will now be described in greater detail with reference to the flat sole plate Ia of Figure 3.

Aligned accurately with the longitudinal centre line of the sole plate Ia are two V-shaped notches 20. Aligned with those V-shaped notches 20 are three square cut-outs 21 formed in the base of the sole plate la, diagonally opposite corners of the square cut-outs 21 forming V-shaped notches accurately aligned with the same longitudinal centre line.

The notches 20 and holes 21 are to be used as described below to align the sole plate la centrally along a marker line created on a cast slab concrete floor of the building under construction. In case it is desired to position the sole plate Ia in an offset position, but still accurately aligned parallel to the marker line, alternative notches 22 and alternative cut-out squares 23 are provided on opposite sides of the axial centre line, each offset by a precise predetermined distance.

Smaller notches 24 and 25 are provided in the longitudinal edges of the sole plate Ia, defining a lateral centre line through the sole plate Ia perpendicular to the longitudinal centre line, and similar lateral lines aligned with the cut-out squares 21 at each end of the sole plate. As the longitudinally aligned notches 20 and 22, the notches 24 are accompanied by similar pairs of notches 25 displaced by the predetermined offset distance, giving greater flexibility in the setting up process. For ease of identification, the notches 20 and 24 are larger than the offset notches 22 and 25, and the cut-out squares 21 are larger than the cut-out squares 23.

At intervals along the length of the sole plate la there are provided recessed dimples 26 at the centre of each of which is a through hole 27. The dimples provide small feet on which the sole plate I a rests in use, as most clearly shown in Figure 2a. They also provide a countersunk housing for the heads of the retaining bolts 5.

Arranged axially down the centre line of the sole plate la is a row of elongate slots 28 the purpose of which is described later.

At precise locations along the axial centre line of the sole plate Ia are upturned flanges which are formed as described below with reference to Figures 4 and 5. In Figure 4 it will be seen that the flanges 29 are created by cutting out a pair of slots 30 from the material of the base of the sole plate Ia.

One of the slots 30 is generally U-shaped, and the other is largely linear.

Between the extremities of the slots, the flange 29 is integral with the remainder of the base portion of the sole plate 1 a through a pair of relatively narrow supporting webs 31. The supporting webs 31 are sufficiently thin that the flange 29 can be pivoted upwardly from the flat position shown in Figure 4 to the upright position shown in Figure 5, and are sufficiently robust that the upstanding flange 29 creates a positive abutment against which the wall frames can be positioned in use.

Use of the sole plates I and I a of Figures 1 to 5 in the setting out method of the invention is as follows. First of all a cast concrete floor slab 4 is laid over suitable foundations. Then the desired outline of the walls of the building (external and internal) is marked on the cast concrete floor slab. That can suitably be achieved by laying out marker lines or wires, by stretching out a flexible line or wire tautly in contact with the surface of the cast floor. Marker paint or a marker dye is then sprayed over the top of the taut line or wire, which when removed leaves a visible line on the concrete in the form of a shadow where the taught line has masked the concrete from the spray paint.

If desired, that marked line can be covered with a transparent moisture resistant barrier such as a varnish or even a transparent sheet of a suitable moisture impervious membrane.

The sole plates I and la can then be positioned accurately, by aligning the lines marked on the concrete with the notches and cut-outs 20 to 25. Each marked line can be located so that it lies directly beneath the angular V of the notches 20, 22, 24 and 25, and with the opposite diagonal corners of the cut-out squares 21 and 23. With the sole plate in position a hole can be drilled in the concreted floor slab through the apertures 27, anchorage bolts 5 dropped into place and the bolts tightened. If there is a small amount of play between the bolts and the apertures 27, then fine adjustment of the position of the sole plates can be achieved prior to full tightening of the bolts 5. As part of the same operation, the sole plate I or Ia can if desired be accurately levelled by placing an appropriate number of thin metal shims beneath one or more of the dimpled feet 26 and the concrete of the floor slab, to compensate for any surface irregularities in the cast concrete floor slab 4 or any departures which that floor slab may have from a true level.

The accurate levelling of the sole plates can be important because in a multi-storey building, a relatively small departure from the true level of the base of the building can result in a significant overhang of some of the outer walls at the top of the building.

Once the floor plates 1 and Ia are accurately secured in position using the fixing bolts 5, the setting out of the wall positions in the building under construction is complete. At that stage the floor can be built up and screeded using insulation boards 6 and screed 7 as previously described, or in the case of sole plates Ia with no longitudinal flanges 3 to support and define the screed depth, the method of the invention can proceed directly to the positioning of the wall frames. The wall frames 9 as shown schematically in Figures 2 and 2a are manoeuvred manually into position, optionally making use of some field lifting equipment to bear the weight of the individual wall panels. Their final position is established by face-to-face abutment of shoulders of the wall frames against the upstanding flanges 29 of the sole plates. It has been possible to align and secure the sole plates I and la with extreme accuracy because they are lightweight and easy to position, and the notches and cut-outs 20 to 25 enable the final positioning of the sole plates to be made without difficulty to accuracies of significantly less than 1 mm. Once the wall frames 9 are in position securely abutted against the upstanding flanges 29, they can be bolted down to the concrete floor slab 4 using bolts 8 which pass through elongate axial slots formed in the bottom bar of the wall frame 9, and aligned axial slots 28 in the sole plate 1 or Ia.

If the wall frames 9 are to be bolted to an upright column of the building under construction, as for example may be desired when the bottom wall has to turn a corner, then the upright columns can similarly be provided with their own sole plates, and positioned exactly as described above for the complete wall frames.

Claims

CLAIMS: 1. A method of setting out and positioning the wall frames of a

modular building that is constructed from a plurality of prefabricated wall frames secured to one another or to upright columns to create a shell framework for the building, comprising the steps of: * creating a cast slab concrete floor over suitable foundations; * marking on the cast slab concrete floor lines corresponding to centre lines or offset centre lines for the wall frames; * positioning over the marked lines rows of metal sole plates to be aligned with the wall frames, the positioning being accurately monitored by aligning angular cut-out portions of the sole plates with the lines marked on the floor; * securing the sole plates to the floor in those precise positions; * aligning the wall frames with the sole plates by bringing the wall frames into face-to-face abutment with upstanding flanges of the sole plates for positive location of the wall frames relative to the cast floor.
2. A method according to claim 1, wherein the angular cut-out portions of each sole plate comprise at least one pair of V-shaped notches cut into the sole plate at opposite ends thereof.
3. A method according to claim 2, wherein the angular cut-out portions of each sole plate further comprise at least one hole cut through the sole plate and having an internal periphery which includes at least one V-shaped notch precisely aligned with an imaginary line connecting the apices of the pair of V-shaped notches at opposite ends of the sole plate.
4. A method according to claim 2 or claim 3, wherein the at least one pair of V-shaped notches includes one such pair precisely located on a longitudinal centre-line of the sole plate.
5. A method according to any preceding claim, wherein each sole plate comprises a base plate portion and a pair of upstanding side flange portions extending longitudinally along the sole plate; and after securing the sole plate to the cast slab concrete floor the floor level between laterally adjacent sole plates is built up using a damp-proof membrane, a flooring grade insulation layer and a finishing screed, leaving one or more recessed channels between the upstanding side flange portions of the sole plates as means for receiving the bottom edges of the wall frames.
6. A method according to any preceding claim, wherein one or more metal shims are inserted at intervals between the sole plates and the cast floor while securing the sole plates and the floor, to achieve an accurate levelling of the sole plates.
7. A method according to any preceding claim, wherein the wall frames are secured to the floor using screws or bolts passing through longitudinal slots in the sole plates.
8. A method according to claim 7, wherein one or more metal shims are inserted at intervals between the bottom of the wall frames and the sole plates, to achieve an accurate levelling of the wall frames.
9. A method according to any preceding claim, wherein the upstanding flanges of the sole plates which provide the positive location of the wall frames are portions of the sole plates which are cut around a substantial proportion of their periphery, remaining attached to the sole plate by two hinge portions only and which are then bent up out of the plane of the sole plate portion from which they are cut, with accompanying bending of the hinge portions.