GB2573298A

GB2573298A - A building with a framework

Info

Publication number: GB2573298A
Application number: GB1807096.1A
Authority: GB
Inventors: Paul Bevington Christopher; Christopher Bevington Tim; William Giddings Brian
Original assignee: Framework Design And Construction Ltd
Current assignee: Framework Design And Construction Ltd
Priority date: 2018-05-01
Filing date: 2018-05-01
Publication date: 2019-11-06
Also published as: EP3564456A1; GB201807096D0

Abstract

The building comprises a plurality of mutually spaced apart framework elements 204 each comprising two flanges interconnected by a web, and secured between parallel pairs of said framework elements structural insulated panels (SIPs) 200 each having an insulative core 208 sandwiched between structural facings 210. The building may comprise a foundation defining a datum level from which the framework extends upwards. The structural facings may overlay the flanges of the framework elements to form a continuous cover over the flanges. The core may be recessed to lie snugly between the flanges of the framework element. The framework may be steel coated with zinc phosphate primer. The foundation may be formed by screw piles. The locations of the tops of the piles may be determined by laser levelling. The SIPs may form walls, floors, ceilings, or roofs of the building. The insulating core may be foamed styrene. The structural facings may be oriented strand board (OSB). The framework elements may be C-section or I-section columns. The building may be for use as a domestic dwelling. The building may be for self-build customers or DIY completion.

Description

This invention concerns buildings, particularly but not necessarily exclusively buildings for use as domestic dwellings.

As is well known, domestic dwellings are expensive, notwithstanding repeated calls by campaigners for so-called “affordable housing”. Aside from the high cost of land, exacerbated in many places by a shortage of suitable building sites, one of the main reasons for the expense of domestic dwellings is that traditional building methods (especially the use of bricks and mortar) are slow, and dependent upon resources (materials and trade skills) that are themselves expensive and in short supply.

It is an object of the present invention to enable domestic buildings to be constructed at lower cost than those currently conventional.

Thus according to a first aspect of the invention there is provided a method of constructing a building comprising the steps of:

(a) forming a foundation which defines a datum level for the building;

(b) constructing on the foundation and securing thereto a framework extending upwards of the datum level, which framework comprises a plurality of mutually spaced-apart framework elements each comprising two flanges interconnected by a web; and (c) securing between parallel pairs of said framework elements structural insulated panels each having an insulative core sandwiched between structural facings, said structural insulated panels being (i) dimensioned to lie between the webs of the framework elements of a said pair and (ii) configured and arranged with the structural facings overlaying said flanges of each framework element of a said pair and the insulative core lying between opposed flanges of each framework element of the pair.

Structural insulated panels, commonly known as SIPs, are available from a variety of suppliers including FastHouse of Limavady, Northern Ireland. The insulative core typically comprises a foam - or possibly a slab - of styrene or polyurethane (PUR) or polyisocyanurate (PIR), and the structural facings between which the core is sandwiched are typically formed of oriented strand board (OSB) although they may otherwise be of sheet metal, plywood, cement or magnesium oxide board. SIPs are strong, with little or no tendency to shrink or move in use. Importantly, also, they meet national standards for sustainable building as set out for instance in the UK Code for Sustainable Homes and the USA Habitat for Humanity.

SIPs are available in various sizes up to 6000mm long or more, and can of course be cut to required dimensions, but in Europe at least a common size is 2400mm long by 1200mm (in USA, 8ft by 4ft) and these dimensions can be used as modular spacing for the framework elements of the present invention. It may be noted that around 170 bricks would be required to cover the same area as a 2400mmx1200mm SIP, even as only a single-skin wall, and could take a skilled bricklayer half a day to lay.

SIPs are also available in various thicknesses, mostly in the range from 100mm to 200mm, and it will be understood that the thickness is related to the profile of the framework elements - so that, for instance, the structural facings of the SIP overlay flanges of the frameworks elements between which it is secured. Commonly, SIPs have an overall thickness of 142mm (USA, 6in) but SIPs of other thickness may be used in the invention.

The construction of foundations for domestic dwellings is conventionally slow and expensive. Detailed plans have to be prepared in advance before groundwork can begin; and then the depth of excavation must be agreed on site with a building inspector, according to the perceived state of the ground. This can hold up the groundworks timetable, meaning that expensive plant and skilled operatives are used inefficiently and, often, neighbours of the site suffer inconvenience for longer than scheduled. Thus, whilst the framework of the present invention - possibly with the SIPs already fitted - can be laid on a foundation of essentially conventional form, with trench/strip footings or concrete rafts/pads, it is preferred to use screw piling.

A screw pile has drive plates extending from a central shaft and arranged in a generally helical formation so that the pile can be driven into the ground by being rotated, using a hydraulic torque head. Screw piles are driven into the ground to a required depth, determined by ground conditions and the building load to be supported by the piles. For the present invention a plurality of piles are driven into the ground at locations defined by the dimensions and footprint of the building being constructed and in relation to core samples obtained eg by a specialist piling contractor, until their tops lie in a common horizontal plane which is the datum level for the building. Those skilled in the art will understand that the screw piles may be in sections joined together as piling proceeds.

In a second aspect the invention extends to a building comprising a framework formed of a plurality of mutually spaced apart framework elements each comprising two flanges interconnected by a web and, secured between parallel pairs of said framework elements, structural insulated panels each having an insulative core sandwiched between structural facings.

Preferably the framework elements are of steel, which is strong and inexpensive. And the SIPs may be used for floors and ceilings, walls and the roof of the building.

Other aspects of the invention will be apparent from the following description, which is made by way of example only with reference to the accompanying drawings which are purely schematic and in which Figure 1 is a simplified isometric view of the configuration of a single storey house embodying the invention, as seen from above and the front;

Figure 2 is a simplified isometric view of a screw piled foundation for the house of Figure 1;

Figure 3 is a simplified isometric view of a steel framework for the house of Figurel.

Figure 4 is an isometric view of a front part of the steel framework as at A in Figure 3, to an enlarged scale relative to Figure 2 and illustrating the way in which SIPs are applied to the framework;

Figure 5 is a plan view in cross-section of a corner of the steel framework as at B in Figure 3, to the same scale as Figure 3 and similarly illustrating the way in which SIPs are applied to the framework above a lower ring beam thereof;

Figure 6 is an isometric view corresponding to Figure 4;

Figure 7 is a perspective view illustrating the construction of an upper ring beam of the framework, as at C in Figure 3 and to an enlarged scale;

Figure 8 is an end elevation illustrating the construction of a ridge of the framework in cross-section;

Figure 9 shows an end elevation of framework elements for the roof;

Figures 10 and 11 are perspective views from opposite ends of the roofing framework; and

Figures 12 and 13 are perspective views illustrating the construction of the roof.

Referring first to Figure 1, the configuration of the house 100 shown therein is simplified in as much as doors, windows and other features are omitted for ease of illustration. The external walls 102 (which may be covered with appropriate cladding, not shown) comprise 2400mmx2400mm SIPs mounted on a steel framework to be described in more detail hereinafter. The internal walls (not shown) also comprise SIPS of smaller dimensions; and in fact, but not shown in Figure 1 for simplicity, the external walls may comprise SIPS 2400mm high by 1200mm wide. Like the walls, the roof comprises SIPs mounted on the steel framework.

For simplicity of description, the height H of the house 100 to its eaves is a nominal 2400mm, its length L is a nominal 9600mm and its depth D is a nominal 4800mm. Actual houses constructed by means of the invention are expected to be substantially larger than these nominal dimensions, and the house may have two or more storeys, and it does not have to have a simple rectangular footprint.

Turning to Figure 2, the house 100 has a foundation formed of screw piles 106 with heavy bearer plates driven into the ground at selected locations set using the Global Positioning System (GPS). As illustrated by Figure 2, the screw piles are located just within the planned footprint 108 of the house, spaced apart at 2400mm intervals. There may well be more screw piles than the nominal number shown purely for illustration in Figure 2 (generally they are spaced apart by an amount equal to three or four times the diameter of the pile helix) and they may be arranged differently from those shown in Figure 2, eg to support a house with a non-rectangular footprint.

The screw piles are driven into the ground by means of rotary hydraulic powerheads to a depth at which it is calculated (in relation to ground conditions) they will support the weight of the house 100. They are then adjusted using a laser so that their tops lie in a common horizontal plane which defines a datum level for the building

The steel framework 110 of the house 100 comprises, as illustrated by Figure 3, the following framework elements: upright girders (ie columns) of the kind generally designated as universal columns (UC) each having two flanges interconnected by a web; horizontal girders (ie beams) of the kind generally designated as UB and each similarly having two flanges interconnected by a web; and inclined UB beams serving as rafters, ridge beams and other components of the roof. The framework elements are of l-section or C-section according to their function and location in the framework, but it should be understood that details of the sections are not shown in Figure 3, for simplicity of illustration. The framework is mostly bolted together, for strength and longevity, but as noted hereinafter welded connections are used in places.

The steel framework 110 is coated with zinc phosphate primer.

As illustrated first of all now by Figure 4, which relates to the part of the framework indicated at A in Figure 3, a SIP 200 (along with other SIPs) is secured in the steel framework, which comprises at its lower end a lower ring beam 202 made from 254x146 UB 37 girder of l-section with a 152x152 Usection column 204 bolted to it by way of a welded end plate 206.

The SIP 200 comprises an insulative styrene core 208 160mm thick sandwiched between opposed structural facings 210 formed of OSB and each 11 mm thick. As indicated at 212, the core 208 is routed or otherwise recessed to lie snugly between the flanges of the column 204 (that is, the flanges extending leftwards as seen in Figure 4). The flanges are spaced apart by an amount (ie 160mm) such that they lie snugly between the overlaying structural facings 210 of the SIP 200, to prevent cold spots and thermal transmission through the assembly. It will be understood that another SIP not shown in Figure 4 is similarly engaged with the flanges of the column 204 that extend rightwards as seen in Figure 4.

Figure 4 does not show the framework elements of the SIP completely. In practice, both the SIP 200 and the column 204 extend upwards from the ring beam by 2400mm, and the SIP 200, preformed as indicated above, is slid down between two parallel columns with their webs spaced apart so that the SIP fits snugly between them widthwise. The SIP is then secured in position.

Sections of 254x148 UB girders such as the framework element 202 are joined together around the periphery of the framework 110 to form a complete lower ringbeam 114 as shown in Figure 3. The lower ringbeam 112 is configured and arranged to sit on and be secured to the tops of the screw piles 106 (Figure 2) to support the house 100. SIPs are slid horizontally between lower crossbeams 114 of the framework 110 (Figure 3) conveniently, while the ringbeam is being constructed - to form a floor for the house 100.

Figure 5 relates to a corner of the framework 110 as indicated at B in Figure 3. It shows, in cross-section as viewed from above, two SIPs 300 and 302 disposed at right angles to form the corner and engaged respectively with a 152x152 UC 23 l-section corner column 304 and a 150x90x24 PFC Csection column 306 welded to it using 150mm hit 300mm miss stitch welding. Each of the SIPs 300 and 302 has an insulative core 308 of styrene foam sandwiched between OSB structural facings 310.

The insulative cores 308 are recessed as hereinbefore described to fit snugly between the flanges of their respective steel columns 304 and 306, which flanges are overlaid by the OSB structural facings 310. The space between the flanges of the l-section corner column 304 that does not receive the recessed portion of the SIP core 308 is filled with insulative material 312 similar to that of the cores 308 and the OSB facing is extended as indicated at 314 to cover the material 312 and provide a continuous OSB cover around the steel framework, to counter cold spots and thermal transmission through the structure. Joints, at corners and elsewhere in the OSB can be secured and sealed with an MS-polymer adhesive, which is also used for securing the insulative filling 312 in place.

For additional clarity, Figure 6 shows the corner at B in perspective, with reference numerals the same as those of Figure 5. It should be noted that the lower ringbeam, which carries the columns 304 and 306, is not shown in Figure

6.

Figure 7 illustrates the framework 110 as at C in Figure 3. An upper ringbeam 116 (Figure 3) is constructed from sections of 178x102 UB girder 400 secured by M16 8.8 bolts 402 to a plate 404 fillet welded to the top of a column 406, and similarly to other columns of the framework 110. Trusses 118 (Figure 3) interconnect the front and rear parts of the upper ringbeam 116 and are secured to the columns by welding and bolting to provide a moment connection., and whilst the upper ringbeam/truss assembly is being constructed SIPs with their insulative cores recessed as aforedescribed are slid between the flanges thereof to form a ceiling for the house.

A ridge for the house 100 is constructed as shown in Figure 8. A 178x102 UB 19 ridge beam 500 is secured to the top of a 152x152 UC column 502 having its top end cut and capped with an end plate 504 at an angle to the horizontal, which thereby defines the inclination of the ridge beam 500. SIPs are fitted, in the manner previously described herein, between mutually parallel ridge beams 500, and each such SIP has a solid timber insert at its outer edge to provide or receive a fascia.

Figure 9 shows framework elements for the roof in end elevation. Front and rear ridge beams in the form of rafters 500f and 500r are each set at a defined inclination and joined together at their apex. At the apex, each ridge beam has a 100mm x 170mm x 8mm end plate 506 secured to it (at an angle to the respective ridge beam so that the end plates are vertically disposed in use) by 6mm fillet welding, and the end plates are then bolted together by way of M18 holes through both the rafters 500f and 500r and press braked. 300mm x 8mm press braked plates form an angled section and are bolted back to form the roof ridge.

Figure 10 and 11 show other details of the roof structure. At opposite ends of the 4800mm long section shown are pairs of 178x102 UB rafters 500 arranged as in Figures 8 and 9. The apex of the roof is formed of two 2400mm long girders 508 joined together at their proximal ends by way of two 150x150x8 rolled steel angles (RSA) 510 welded together back to back.

Referring now to Figures 12 and 13, these use the same reference numerals as Figures 10 and 11. SIPs 200 (of which only one is shown in Figures 12 and 13) like those used to form the floor, ceiling and walls of the house 100 are also used to form the roof. They are located between the flanges of the rafters 500, where they are held in place by the vertical webs of the RSA framework elements 510, and they rest on the lateral webs of the RSA framework elements. The assembled roof is covered by cladding such as the Colorcoat Urban (Registered Trade Mark) system supplied by Tata Steel Europe Limited, headquartered in London.

Those skilled in the art will now appreciate that the main features of the invention in its preferred form are as follows.

Floor cross-beams are welded to an array of GPS-positioned screwbored piles with heavy bearer plates. Each pile is designed and installed to support a load of up to 20,000kgf, and the building including framework plus SIPs and building fittings weighs about 10,000kgf.

Deep, heavy-duty l-section girders are used to construct a peripheral ring beam. SIPS having a 160mm thick insulative core of styrene foam sandwiched between two 11mm OSB structural facings are installed between the webs of the cross-beams to form a floor. The floor is covered with particleboard flooring such as the CaberDek (Registered Trade Mark) flooring available from Norbord Europe Limited of South Molton, UK, which flooring has a wear-restant, water-resistant and slip-resistant coating.

An upper ringbeam is constructed to complete a box-like structure for the steel framework.

Walls of the building are formed of SIPs 2400mm high and either 1200mm or 2400mm wide, with made-to-measure or cut-to-size end panels. The SIPs completely enclose the girders, to prevent cold spots, and are themselves enclosed by 25mm cavities and membranes, within inner and outer finishing cladding. The inner cladding may be skimmed plasterboard or, like the outer cladding, to choice. Double-cladding - to a total thickness of about 240mm- offers U-values better than 0.17W/m²K, exceeding current targets such as the norm of 0.21 W/m²K adopted by the European Mineral Wool Manufacturers Association (EURIMA). It also provides good results in airtightness, for passive housing.

According to customer choice, windows and doors may be sealed double- or triple-glazed units.

A key aim of the invention is to offer, at an extremely competitive price, a house with a build time of only three to five weeks which is especially suitable for DIY completion. The house as delivered would include basis first-fix facilities for water, sewage and electricity. And it would be ready for purchasers to choose and fit out their own kitchens, bathrooms, and utility areas with appliances. (This has a particular advantage in the self-build market. The house as delivered is adequate for a purchaser to move into it - not into a caravan or tent on site - and complete the house within their own timescale and budget).

However, whilst the invention is particularly suitable for self-build customers, who can complete it to their own particular requirements and to their own timescale, the plain vanilla structure it delivers is likely to be attractive also to developers, local authorities and housing associations

The invention allows a wide variety in design, even within the modular configurations using standard 2400mmx1200mm SIPS. Beyond that, SIPs of longer length can be used, with no need for jointing; and SIPs can be cut to a required length.

The building may have a single-pane flat roof or a pitched roof which may be covered by cladding such as the Colorcoat Urban (Registered Trade Mark) system supplied by Tata Steel Europe.

Claims

CLAIMS The invention claimed is:

1. A method of constructing a building comprising the steps of:

(a) forming a foundation which defines a datum level for the building;

2. A method of constructing a building as claimed in Claim 1 characterised in that said framework elements are formed of steel.

3. A method of constructing a building as claimed in Claim 1 or Claim 2 characterised in that said framework elements are mutually spaced apart by a modular distance defined by the length and breadth of the structural insulated panels.

4. A method of constructing a building as claimed in any preceding claim characterised in said foundation is formed by a plurality of screw piles driven into the ground at the site for the building., to form said to a depth where their tops lie in a common horizontal plane said tiles are secured to an existing deck to cover the same.

5. A method of constructing a building as claimed in Claim 4 characterised in that the screw piles are driven into the ground to a depth at which their tops lie in a common horizontal plane representing said datum level.

6. A method of constructing a building as claimed in Claim characterised in that the location of the tops of the screw piles is determined by laser levelling.

7. A method of constructing a building as claimed in any preceding claim characterised in that some of said structural insulative panels are secured between said parallel pairs of framework elements vertically disposed so as to form walls of the building.

8. A method of constructing a building as claimed in any preceding claim characterised in that some of said structural insulative panels are secured between said parallel pairs of framework elements horizontally disposed so as to form a floor and a ceiling of the building.

9. A method of constructing a building as claimed in any preceding claim characterised in that some of said structural insulative panels are secured between said parallel pairs of framework elements inclined to the horizontal so as to form a roof of the building.

10. A building comprising a framework formed of a plurality of mutually spaced apart framework elements each comprising two flanges interconnected by a web and, secured between parallel pairs of said framework elements, structural insulated panels each having an insulative core sandwiched between structural facings.

11. A building as claimed in Claim 10 characterised in that framework elements are formed of steel.

12. A building as claimed in Claim 11 characterised in that the framework is coated with zinc phosphate primer.

13. A building as claimed in any of Claims 10 to 12 characterised in that insulative cores of the structural insulated panels are recessed to receive flanges of the framework elements, with the cores fitting snugly between the flanges and the structural facings overlaying the flanges.

14. A building as claimed in any of Claims 10 to 13 characterised in that insulative cores of the structural insulated panels are formed of foamed styrene.

15. A building as claimed in any of Claims 10 to 14 characterised in that the structural facings of the structural insulated panels are formed of oriented strand board.

16. A building as claimed in any of Claims 10 to 15 characterised in that the structural insulated panels secured to the framework form a floor, internal and external walls, a ceiling and a roof of the building.

17. A building as claimed in Claim 16 characterised in that the floor is covered with particleboard having a wear-resistant, water-resistant and slipresistant coating.

18. A building as claimed in Claim 16 or Claim 17 characterised in that the internal walls are covered with skimmed plasterboard.

19. A building as claimed in Claim 16 of Claim 17 characterised in that the external walls are sealed and covered with weatherproof cladding.

20. A building as claimed in any of Claims 16 to 19 characterised in that the roof is covered with weatherproof cladding.

21. A prefabricated kit of parts for a building as claimed in any of Claims 10 to 20, which kit comprises framework elements cut to length to form said framework and accommodate said structural insulated panels to form a floor, internal and external walls, a ceiling and a roof of the building.