AU648918B2 - Building construction method - Google Patents

Description

48918 S F Ref: 215988

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIRCATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Christopher Jones 227 Eastern Road Wahroonga New South

AUSTRALIA

Christopher Jones Wales 2076 Actual Inventor(s): Address for Service: o Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Walps, 2000, Australia Building Construction Method Invention Title: ASSOCIATED PROVISIONAL APPLICATION DETAILS [31] Application No(s) [331 Country PL0378 AU [32] Application Date 13 Jan,'ry 1992 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815/3 -2- BUILDING CONSTRUCTION METHOD FIELD OF THE INVENTION The following invention relates to a building construction method.

More particularly, though not exclusively, the Invention relates to a method of constructing residential buildings with sound and fire ratings. It is particularly suited to medium to high density housing.

PRIOR ART There are various methods of constructing single or multi storey domestic dwellings. Taking a two storey building for example, full brick/block construction with an insitu intermediate concrete slab is commonly adopted for homes, units and townhouses, especially where significant sound and fire rating standards are required. It is usual in this construction method to have footings under all internal and external walls. Materials handling of the bricks is slow and labour intensive.

The brick/block workers are usually exposed to the weather during the construction phase. Heavy beams sometimes require lifting and positioning. Traditional timber formwork is usually used to form the intermediate slab and is labour Intensive on site. Difficulties often arise in services Installation within wall thicknesses and, because of limited access, can usually only occur after the formwork is stripped out. Chasing the brick walls for plumbing and electrical services also weakens the structural integrity of the wall. The walls are finished as face brick, painted brick/block, bagged and painted, or rendered and painted. Sometimes walls show foundation settlement cracks, or cracks 25 due to slab shrinkage.

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Another form of residential construction is by way of lightweight steel wall framing to form a a non fire rated brick veneer house. The framing is usually fabricated at a factory and transported to the building site. The framing is erected after the ground slab has been poured and provides the structural strength and stability of the building, and to which cladding and internal linings are fixed. Steel framed residential construction also occurs in medium density housing where a sole occupancy may occupy one or two storeys/floors. Limitations at the moment are that where sole occupancies occupy a space one above the other separated by an intermediate floor and the building contains more than two sole occupants, the significant sound and fire rating KEH:29811 -3standards specified on that floor are such that steel or timber beamsjoists are not suitable. A concrete floor is considered suitable because it provides a fire barrier from both directions. Hence the use of structural steel wall and floor framing (with Base Metal Thickness of about ,75 to 1.2mm) is usually limited to non fire rated buildings.

There are fire rated wall systems using lightweight steel studs and fire-rated plasterboard. These are constructed after the concrete floors and columns etc. are in place i.e. forming lift shaft walls or walls surrounding vertical service ducts or separating hotel rooms etc.

A similar building construction method is to be found In timber framed residential buildings. The construction method is similar to that of steel frame residential brick veneer buildings except, the framing is in timber. In addition to the problems described above in relation to steel framed residential brick veneer buildings, termite attack is a 15 significant problem. Furthermore, warping, twisting and shrinkage causes linings to crack. Poisons to deter termites cause serious risk to the environment.

A further known construction method is that of Autoclave Aerated :Concrete (AAC). This is a light weight cement based construction 20 material produced in block and panel form, workable using standard wood working tools. A problem of this method is the reliance placed on on-site workmanship. Accuracy to take intermediate floor panels is critical to low strength blocks/panels. Stability of building elements using the aerated material is unknown. It is a relatively new material.

25 Footings are required under all walls as compared to no footings being required in the case of internal walls for steel timber framed brick veneer buildings.

l';iere a building has more than two sole occupancies, occupying space one above the other, each occupant requires their own independent fire rated compartment. A concrete intermediate floor slab provides an acceptable barrier, providing protection from fire In either direction.

The current common method of constructing a residential building with intermediate concrete floors Is to construct fire rated continuous brick walls which act as partitions between rooms and provide a fire rated load bearing capacity. The disadvantages of this method of construction are heavy materials handling, the effect of rain during KEH:29811 -4construction hindering work of tradesmen, and for example ccnjested formwork meaning that services can only be installed after the formwork has been stripped out.

For buildings with three or more storeys, the capacity of the brick walls can reach their limit, and the designers usually adopt a reinforced concrete column and slab method. This gives an added benefit to the construction program because, once the temporary formwork is stripped out, it provides the builder with a building transformation of the first order to have large working areas to build in-fill walls and direct other activities, and with floors over, provides for web weather or sun/heat protection.

Variations to this procedure have been the use of heavy gauge steel frame multi-storey buildings, like city office blocks, wherein the steel frames are sprayed or concrete encassed to provide the required fire rating. Such a method of construction it seems, is not viable for residential construction.

OBJECT OF THE INVENTION It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

DISCLOSURE OF THE INVENTION There is disclosed herein a building construction method for multi-storey buildings, comprising per storey not being a top storey: erecting temporary support towers; laying corrugated sheeting above and so as to be supported by 25 the towers; during step and/or or thereafter, constructing load .bearing walls beneath and adapted to support the corrugated sheeting; pouring a concrete floor upon the corrugated sheeting; removing the temporary support towers, and 30 erecting a lightweight steel external wall frame before, during or after steps to e p RLF/00761 5 There is further disclosed herein a temporary support tower when used to construct a building as disclosed above, comprising: a frame of steel tubing members, at least some of which are vertically orientated when erected; a plate locater attached to the frame; and a steel plate attached to the plate locater and comprising a raised section adapted to deform said corrugated steel sheet when positioned thereon.

The steel bearing plate may comprise a raised section adapted to deform said corrugated steel sheet when positioned thereon.

Typically during the construction period, stability is provided by the temporary towers, and with vertical and horizontal construction loads on floor support sheeting transferred to the towers.

The new building construction method expands the use of light weight steel framed structures to include sound and fire rated buildings. It is essentially a reinforced concrete column and slab *o *~o *o~e ofo *e* o* *e RL/0* structure. The difference is the method of construction. It uses temporary and permanent steel to facilitate multi-level simultaneous trade construction with wet weather protection by means of the building having a spacial transformation of the second order, i.e. walls overhead are fixed in place with or without services installed before the concrete columns and intermediate floor slabs are constructed.

Also where no fire rating to certain wall sections apply, then steel posts/columns in lieu of brick/concrete block load bearing elements will usually be selected.

It is envisaged that a significant cost saving will result from the construction method disclosed above, as compared to the above described prior art building construction methods.

The above described building construction method nay be ideal for integrated computer design, drafting and manufacturing. Fast and accurate design and the simple detailing may lead to increased design and construction productivity.

Typically, fewer strip footings than are required under the prior art construction methods will be necessary.

Furthermore, a lower material handling burden will be required 20 on-site.

Shorter construction periods are envisaged especially in wet weather conditions.

The method may also provide for accurate building alignment.

Termites should not be a problem. It is also envisaged that a reduction S 25 in floor vibration and noise transmission will be achieved as compared to steel or timber joist floor systems. Standard fire rated lintels may be utilized. Usually, no heavy steel beams require lifting during construction. Usually a flat soffit will be possible.

In accordance with the second form of the invention there is further disclosed herein a method of constructing a building similar to that disclosed for the first form of the Invention except the internal wall framing, and external wall framing not temporarily supporting roof loads, are left out at step and transferred to step as described in the first form, after point The inventor considers the second form of the invention to result in a slower overall construction time, with the trade off being easier and perhaps faster concreting time but most of the multi-level vXC ,1H:29811 4 7 8:simultaneous trade construction benefits are lost. Also installing and manoeuvring the wall framing panels is restricted by concrete floors existing above and below; the activity would have to wait until falsework is stripped out; and the benefits of computer aided design and manufacture of the wall framing controlling accurate building set out is lost. These disadvantages would also be common with other traditional prior art methods especially those described with spatial transformation of the first order.

In accordance with a third form of the invention, there is further disclosed herein a third construction method for multi-storey buildings after completion of the ground/base slab, comprising: setting out and fixing internal and external steel wall framing with or without services partly installed, and external wall framing not passing through slab; erecting temporary support towers; locating first stage bearers supported on towers; laying out the corrugated sheeting usually over this entire floor area for the purpose of: temporarily supporting floor construction loads (but not 20 wet concrete at this stage); (ii) providing lateral support to internal and external wall framing; (iii) providing more clear access for installing or connecting already installed services; 25 (iv) being designed (and usually, but not necessarily, modified with second stage manufacture) to facilitate further slab strips 2 or part of slab strips 2 of same thickness to be formed usually within one length of sheeting, to span compositely with concrete in two directions usually at right angles to each other (see Figs. 3(b) and and supporting and forming wet concrete.

fixing the slab edge formwork; constructing the block/brick/concrete load bearing elements; pouring a concrete floor upon the corrugated sheeting; repeating steps to for each storey.

This form provides more clear access for pouring the concrete (with .9811 no obstructions such as towers or steel wall framing). The trade off for this benefit is more exposure to sun/heat and wet weather, and much less trade independence, not continuous trade work unless the project is large enough for builder/project manager to direct trade work to other areas.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a part sectional elevational view of a building during construction, Fig. 2 is a schematic sectional elevatlonal view of a building being constructed at Fig. 1 showing load bearing block elements, Fig. 3a is a schematic cross sectional view of bearers supporting metallic sheeting above a temporary support structure in a building under construction, OO• Figs. 3b and 3c are cross sectional views showing sheeting after second stage manufacture, Fig. 4 is a schematic elevational view of a temporary support frame, Fig. 5 is a schematic plan view of a load bearing plate, 20 Fig. 6 is a cross sectional elevational view taken at X-X in Fig.

and Fig. 7 is framing details of internal walls, Fig. 8 is a schematic cross sectional elevational view of an intermediate floor slab supported by block work.

25 DESCRIPTION OF THE PREFERRED CONSTRUCTION PROCEDURE A general construction procedure is as follows: Sieel framing are fabricated off-site during the site clearing interval. The steel corrugated sheeting is cut to length to usually cover width of building in one piece and then passed through second stage manufacture. Footings and ground slab are then prepared while steel fabrication continues, Once fabrication is complete, the steel framing may be erected and fixed.

Brick or block load bearing elements can then be constructed or left until later. After erection of the temporary steel support frames, bearers and/or brick or block work, the Bondek sheeting or similar may be laid and fixed. Upon laying of the Bondek sheeting or similar, a I -SK 29811 IYT 9 concrete slab may be poured thereon, or left until later. It is possible to often temporarily support roof trusses on external wall framing without any intermediate concrete floor slabs being poured.

Typically plumbing and electrical services fixed to walls may now commence much earlier because steel sheeting, requires less support than conventional formwork, and, when combined with two stage propping, facilitates more clear access.

Roof coverings may be placed upon the roof trusses/framing before or after pouring of the intermediate concrete slabs.

Once steel framing erection is complete, external cladding may commence. Internal linings may then be fixed after service installation is complete. Any finishes may be effected as the last step of the i procedure. SO In the drawings various aspects of the construction are depicted.

Bondek or other corrugated steel sheeting 10 is shown supported by temporary load bearing elements or support frames 12. External cladding 11 may be laterally supported by a steel frame 12 and can be vertically supported (from ground level only or at each level). Steel frame 12 may support lintel beams etc. Brick or block load bearing element 13 extend 20 between slabs 10 and between the first floor slab and the ground floor.

The construction of walls between may comprise steel studs plus plaster board or other lining. Dry in-fill may be fixed between the plaster board sides to reach sound and other building code requirements.

Alternately Autoclaved aerated concrete blocks can be used and finished 25 with O10mm plasterboard each side. Prior art options can also be used.

S" Reference shall now be made to the individual drawings accompanying the application.

Fig. 1 shows a three storey dwelling under construction.

Separatirg each floor is a Bondek or other corrugated steel reinforcing sheet. Supporting each sheet is a temporary support tower 12 which is to be removed once the brick, concrete, or block wall elements 13 are in place to support the full load of the dwelling. The temporary support towers usually have tie rods fixed to ground slab to enhance stability.

With particular reference to Fig. 3, a steel channel section 30 supports, by way of timber packing 31, extra bearers to support the Bondek sheeting At the vicinity of the support tower 12, the Bondek ribs are )0 flattened. Flattening of the Bondek ribs allows decking to cover right across the building in one piece to shut off rain water. It also allows the 3ondek slab to be designed to span in two directions within one sheet length. Conventionally, Bondek is designed to span one direction for the length of the sheet, then loads are transferred on to a steel/concrete beam or strengthened slab strips. Reference should be made to Figs. 3B and 3C for details of several existing corrugated steel sheet products after second stage manufacture.

Either the timber packing 31 or U heads 32 may support wooden bearers 33 upon which the decking 10 is supported. A U-bolt 34 may aid in securing the various components together.

With particular reference to Fig. 4 a single temporary support tower 12 is depicted. Tower 12 may have a plate locater 40 held by a technician against it to accurately locate the plate 50 (Fig. 5) beneath 15 the Bondek sheet 12. Plate 50 comprises a circular hollow section 51

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.welded centrally thereon. The outside diameter of the raised circular hollow section 51 is smaller than the internal diameter of the vertical support frame leg 62. Reference should be made to Fig. 6 which shows a Bondek sheet 12 being deformed by the hollow section 51 and providing a 20 convenient visual identification from above of the correct location for support frame leg 62. The deformation of the Bondek sheet 12 serves as a mechanical means to laterally transfer horizontal loads from external framing which may be carrying temporarily roof loads, and other horizontal construction loads to support frame 12.

25 Figure 7 shows typical internal wall framing. The bracing shown and then cut later, is used to stabilize some frames when chaired and fixed to corrugated sheeting prior to pouring concrete. The third form of the invention would also norn.ally have the external stud framing detailed in a similar way.

Turning now to Fig. 8, a portion of the finished structure is depicted. Shown is a concrete slab 71 formed by Bondek 12, the edge of slab 71 being sunported by block wall elements 13. The external cladding 11 may be located in a conventional manner about the constructed dwelling. Fire rated plasterboard 72 is shown connected by way of fire rate sealant 73 to the block wall elements 13.

Several construction procedures shall now be described; In a first optional construction procedure, after completion of the fi H:29811 .9' ground slab 15, steel wall framing 12 is delivered to site, sorted, and an approved shutter release agent applied to the studs for a length of at least 500mm up from each Intermediate floor slab level. This will advantageously allow easier removal of any concrete splatter for fixing wall linings.

The external wall studs can temporarily support roof trusses 16, and polystyrene blocks, are wrapped with an approved plastic membrane, for the depth of slab at intermediate floor levels.

Internal and external wall frames 12 are located and fixed for a particular storey.

Th internal walls are temporarily braced and supported on chairs, and fixed to the decking. The exter'al wall studs pass through the slab often to the roof.

False work/temporary support towers 12 are erected.

Bearers 33, joists and packs are located and fixed.

Bondek (or equivalent) sheeting is laid out and fixed.

Each level is finished including forming the slab edge along external stud framing, providing stud restraint by fixing connector plate 1.0mm thick between studs to the Bondek edge.

20 The above procedure is repeated for each level up to the roof level.

The builder now hs an accurate building skeleton allowing for multi-level simultaneous trade work with sun and wet weather protection to install electrical, mechanical and plumbing services at all levels, to construct block load bearing elements and external brick walls, to 25 construct stairs and balcony formwork, to pour intermediate floor slabs, to apply fire sealant, remove polystyrene blocks and plug holes with fire pillows and/or sealants, and to fix wall and ceiling linings etc.

For the first form of the invention/construction method the inventor forsees a 50% saving in construction time.

As an advantage, no footings under internal walls are usually required. Only pad footings under concrete block wall elements are usual, depending on ground conditions. Accordingly, plumbing installation and electrical services installation are made easier.

Light weight building materials may be used. The wall framing sections typically, have a base metal thickness between 0.75mm to 1.2mm.

Accordingly, a typical 6mm long wall panel can be carried by two persons. The Bondek sheeting is lightly propped.

a- The inventor forsees no set out and levelling problems in forms one ard three. It is envisaged that the wall framing be computer generated and fdbricated with dimensional accuracy. Therefore, the total building skeleton is rapidly erected, levels are built in, and setting out services is easier prior to or after concrete pouring.

Usually, iio external permanent scaffolding is required.

As a most Important advantage, more clear floor access on each floor level is provided. The Bondek sheets require less propping/formwork than conventional formwork. The propping/falsework for the new system is erected in two stages. That is, the temporary support towers 12, bearers, Bondek, wall framing, and slab edge formwork at external stud wall framing is erected to provide early trades access, and the builder add extra props below the level immediately prior to pouring concrete.

15 This two stage falsework is forseen as allowing better access for as long as possible. Also the common walls betvaen units are often only constructed after the concrete has been poured.

As a further advantage, there is usually no interrupted service installation. The multi-level trade construction allows early access for trades work at all levels. This construction method creates less trade interdependence, reducing downtime or breaks and time lost during construction.

Fewer wet weather and heat days lost are expected. After the building skeleton has been erected, the roof can often be clad. With early planning and with engineer approval, a prevailing wind side wall :can also be clad to improve water tightness during construction.

As a further advantage, reduced formwork handling and strippin, out on each floor is achieved using Bondek, which also usually acts as bottom reinforcement for the concrete slab.

Accurate set down in wet areas are easier to achieve because wall framing is in place.

Consistent slab thickness and ceiling level can usually be achieved throughout the entire building.

set downs in wet areas can be achieved without adjusting overall intermediate floor/ceiling thickness.

Accurate concrete level markers are provided during the pour by screeding to: S KEl: 29811 o' 0'} 13 under side of the steel wall framing, and (ii) marks on PVC sleeves on each leg of the towers.

Usually, no concrete beams/llntels need t, formed up, only a flat concrete Bondek floor is required.

No temporary perimeter handrails are usually required for safety.

The light weight steel studs at 600mm centers and nogging around the building provides the barrier. Some handrails may be required where framing is interrupted.

Overall, reduced overheads as a result of early completion are expected.

A second optional construction procedure may be possible. The second optional procedure comprises; After completion of the ground slab 15, the steel wall framing 12 is delivered to site and sorted.

15 The external studs do generally pass through the slab so the studs do need plastic wrapping.

external wall frames 12 are located and fixed for the particular storey current.

temporary support towers 12 are erected.

bearers 33 and packs are located and fixed.

metal decking 12 is laid out and fixed.

slab edge formers are fixed.

repeat steps to often to roof level.

the load bearing elements 13 are then constructed.

second stage propping is added one floor at a time.

concrete is poured over the Bondek sheeting one floor at a time.

steps and are repeated up to roof level.

During the repeated steps, the builder has access to the lower stories to complete wall framing, services and fit out.

A third optional construction procedure is similar to option 2 except, the external studs do not generally pass through the slab to temporarily support the roof. So plastic wrapping and polystyrene is not needed on the studs. Such a procedure is suitable in good weather conditions, and where the project is large enough to minimise trade independence by redirecting activities to other areas.

It should be appreciated that modifications and alterations obvious KEj' 29811 wNT to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, the steel framing discussed herein may be replaced with wooden framing for example.

A building construction method for sound and fire rated residential multi-storey buildings, comprising three forms of the invention using almost the same details but different sequence of activities to achieve the same end result is disclosed. The three sets of sequences also achieve different overall times taken for total building completion with the first form forseen as the fastest. The second form is anticipated to be the second fastest (weather permitting) with easier (no obstructions) concrete pouring, trading off against reduced spatial transformation to facilitate maximum multi-level simultaneous trade construction. All three forms are considered by the inventor to have optimum material costs versus speed of construction (and associated cost savings) than any other 15 prior art method to achieve an acceptable sound and fire rated residential buildings.

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Claims (9)

1. A building construction method for multi-storey buildings, comprising per storey nct being a top storey: erecting temporary support towers; laying corrugated sheeting above and so as to be supported by the towers; during step and/or or thereafter, constructing load bearing walls beneath and adapted to support the corrugated sheeting; pouring a concrete floor upon the corrugated sheeting; removing the temporary support towers, and erecting a lightweight steel external wall frame before, during or after steps to

2. The method of claim 1 wherein external cladding is erected about said external wall frame.

3. The method of claim 1 or claim 2 further comprising applying internal linings to the lightweight sheet frame and/or load bearing wall elements.

4. comprising

5. constructed (g) step The method of any one of the preceding claims further applying finishes. A method of constructing a top storey of a building 1 according to any one of the preceding claims, comprising: erecting temporary support towers upon the floor produced in S. 5 S S. applying roofing; erecting internal walls during step or thereafter; and removing the temporary support towers.

6. A temporary support tower when used to construct a building in accordance with the method of any one of the preceding claims, comprising: a frame of steel tubing members, at least some of which are vertically orientated when erected; a plate locater attached to the frame; and a steel plate attached to the plate locater and comprising a raised section adapted to deform said corrugated steel sheet when positioned thereon.

7. The support tower of claim 6 wherein the raised section is circular and of external diameter less than the internal diameter of the steel tubing members. A FTO7< LF/00761 16

8. A building construction method substantially as hereinbefore described with reference to the accompanying drawings.

9. A temporary support tower when used to construct a building in accordance with claim 8, the support tower being substantially as hereinbefore described with reference to the accompanying drawings. DATED this TWENTY-THIRD day of FEBRUARY 1994 Christopher Jones Patent Attorneys for the Applicant SPRUSON FERGUSON a. a o BUILDING CONSTRUCTION METHOD ABSTRACT OF THE DISCLOSURE A building construction method comprises erecting temporary support towers 12, laying corrugated sheeting 10 above and so as to be supported by the towers 12, erecting load bearing walls 13 beneath the corrugated sheeting 10 and removing the temporary support towers. Figs. 1 and 2. S:* S* 5* *oo 0.: KEH:29811