GB2489692A

GB2489692A - On site filling of wall cavities of a prefabricated building

Info

Publication number: GB2489692A
Application number: GB1105623.1A
Authority: GB
Inventors: Qusai Abdul Latif Jassim Alani
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-04
Filing date: 2011-04-04
Publication date: 2012-10-10
Also published as: GB201105623D0

Abstract

A method of constructing a building comprises providing a prefabricated building unit (1) having a cavity wall (2) comprising a first skin (3) and a second skin (4) with a cavity (5) in between. The prefabricated building unit (1) is installed on a site, and the cavity (5) of the cavity wall (2) is filled after the unit (1) is installed on site. The cavity may be filled with a settable material such as concrete or with a loose fill material such as sand. Reinforcement and insulation material may be provided in the cavity. The building unit may be provided with services pre-installed in the cavities.

Description

METHOD OF CONSTRUCTING A BUILDING

The present invention relates to a method of constructing a building.

In places which experience long periods of hot weather there are often laws preventing construction workers from working outside during the heat of the day. This consequently extends the length of time to construct a building and costs the developer money.

To lessen the amount of time construction workers would be working outside, a building may be constructed using prefabricated building panels which are formed inside, for example, a factory. These may be formed from precast concrete panels which include reinforcement. The prefabricated building panel may also be a cavity wall with insulation in the cavity. The building panels are transported and installed on site using tower cranes and other heavy machinery. Large building contracts are required in order to make it profitable to construct buildings from such prefabricated building panels due to the investment required in equipment and machinery.

As an alternative, low cost lightweight portable buildings, such as portable cabins, can be formed in factories and transported to site, where they can be used almost immediately. However, these are not designed to form long-term permanent structures. Thus, funding available to developers for long-term buildings would not be available for such portable buildings.

It is an object of the present invention to provide a method to alleviate the above-mentioned problems.

According to one aspect of the present invention there is provided a method of constructing a building comprising the steps of: (a) providing a prefabricated building unit having a cavity wall comprising a first skin and a second skin with a cavity in between; (b) installing the prefabricated building unit on a site; and (c) filling the cavity of the cavity wall when the unit is installed on site.

By providing the prefabricated building unit with a cavity wall, a more permanent structure can be formed for which funding would be available. By not filling the cavity until the building unit is on site, a lighter building unit can be initially provided which would be easier and cheaper to transport than a building unit with a filled cavity wall. The prefabricated building may comprise a plurality of cavity walls which at least partially enclose a space. The prefabricated building may comprise a single wall or a part of a wall.

The method preferably includes the step of providing shuttering for at least one of the first and second skins of the cavity wall before the cavity is filled and removing the shuttering after the cavity has been filled. The shuttering supports the at least one skin as the cavity is filled.

The method may also include the step of preparing a concrete foundation on site for the prefabricated building to be installed on.

Step (a) of the method may include providing the prefabricated building unit with a wall frame, the wall frame being within the cavity of the cavity wall.

The wail frame may be arranged to allow fill material to pass down through the cavity to permit filling of the cavity from a top of the cavity wall. The wall frame may be a steel frame. The wall frame may comprise a portion of a structural steel frame. The wall frame may comprise a wooden frame.

Step (c) of the method may comprise filling the cavity with concrete. The concrete may comprise fibre reinforced concrete. Fibre reinforced concrete is particularly effective at providing protection from explosive blast forces. The cavity may be filled with sand which is well known for its penetration stopping capabilities. The cavity may be filled with debris. The cavity may be filled with any other kind of ballasting material preferably having a relative density of at least 1.4.

The cavity may include insulation and/or steel reinforcement. These are preferably to be within the cavity before the cavity is filled.

The method may include the step of installing at least one metal plate in the cavity before the cavity is filled. The metal plate(s) may be of hardened steel. The metal plate(s) preferably extend over substantially all of at least one wall or wall unit of the building.

The prefabricated building unit may have a roof unit installed on it. The roof unit may be a precast concrete roof unit.

At least one of the first and second skins of the cavity wall may comprise cement board. At least one of the first and second skins may comprise lightweight concrete or cement board. At least one of the first and second skins may comprise gypsum board. One of the first and second skins may comprise lightweight concrete and the other of the first and second skins may comprise gypsum board. The cavity wall is preferably an external cavity wall. The wall may be covered with a decorative material.

Step (a) of the method may include providing the prefabricated building unit with services accommodated within the cavity. The services may be for electricity and plumbing. The services may include, for example, wiring for lighting, telephones, televisions and computers.

The prefabricated building unit may include a bathroom with a toilet, wash-basin and shower. The prefabricated building unit may have at least one wall and may include at least one floor. Ceramic tiles may be used to cover a said wall and/or floor.

The prefabricated building unit may form an extension to a house or villa.

It may be erected on the roof top of a building. A number of prefabricated building units may be used to form a two or three storey building which may be a house.

An assembly production line may be used to make the prefabricated building units. This produces standardization and reduces costs in materials.

The prefabricated building unit may contain various fittings such as windows, electric wiring, plumbing and tiling which means that there is minimal building work on site which reduces cost. The prefabricated building unit can be used to form superior affordable housing.

According to another aspect of the present invention there is provided a method of constructing a building comprising the steps of: (a) providing a prefabricated building unit having an inner skin of an external cavity wall; (b) installing the prefabricated building unit on a site; (c) building the outer skin of the external cavity wall for the building unit when the unit is installed on site; and (d) filling the cavity of the external cavity wall.

The method preferably includes the step of providing shuttering for the inner skin of the cavity wall before the cavity is filled and removing the shuttering after the cavity has been filled.

The outer skin may be fixed to the inner skin by connectors. The outer skin may be fixed to a wall frame by connectors wherein the wall frame is between the outer and inner skins.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which: Figure 1 is an elevational view of part of a prefabricated building unit for implementing the construction method according to one embodiment of the invention; Figure 2 is a sectional view of a foundation being constructed for the prefabricated building unit; Figure 3 is a sectional view of the prefabricated building unit after the construction method has been completed; Figure 4 is a sectional view of part of a modified prefabricated building unit having a cavity wall prepared to receive filling material; Figure 5 is a sectional view showing the part of the modified prefabricated building unit of Figure 4 after the construction method has been completed; Figures 6 and 7 are opposite side elevational views, respectively, of a structural steel frame box that forms the frame of a modified prefabricated building unit; Figure 8 is an end elevational view of the structural steel frame box; Figure 9 is a plan view of part of a prefabricated building unit implementing the construction method according to another embodiment of the invention; Figure 10 is a sectional view taken along lines 10-10 on Figure 9; Figure 11 is a sectional view of a foundation for the prefabricated building unit of Figures 9 and 10; Figure 12 is an elevational view of part of the prefabricated building unit of Figures 9to 11; Figures 13 and 14 are sectional views taken along lines 13-13 and 14-14, respectively, on Figure 12; Figures 15 and 16 are details of Figures 13 and 14, respectively; Figure 17 is a sectional view of part of a modified prefabricated building unit which includes steel plates; Figure 18 is a sectional view of a modified prefabricated building unit for receiving sand/debris; Figure 19 is a perspective view of a prefabricated building unit for supporting a wall; and Figure 20 is a sectional view of the prefabricated building unit of Figure 19 supporting a wall.

Referring to Figures 1 to 3 of the accompanying drawings, a prefabricated building or cabin unit I includes a plurality of external cavity walls 2 which enclose a space. Each external cavity wall 2 comprises an outer skin of marine plywood panels 3 which may be 18 mm thick and an inner skin of gypsum board panels 4 with a cavity 5 in-between. A steel wall frame 6 is provided within the cavity 5 of the cavity wall 2 and comprises a grid formed from horizontal and vertical steel tubes 7, 8. The top of the frame 6 has an inverted steel angle 9.

In order to install the prefabricated building unit 1 on a site, a concrete foundation 10 is prepared. It initially comprises a trench 11 dug below ground level 12 and then filled with concrete. Blackboard shuttering 13, 13' (see Figure 2) is used to form a ridge 14 above the filled trench 11. The shuttering 13, 13' may be 18 mm thick. Shuttering 13' on the inner side of the ridge 14 is removed and space within the ridge 14 is filled with compacted soil 15. A concrete floor slab 16 is formed above the ridge 14 and compacted soil 15 and the top of the floor slab 16 is covered in concrete and ceramic tiles 17.

The prefabricated building unit 1 is transported to the site and is installed on the foundation 10. Shuttering is placed against the outer surface of the outer skin of marine plywood panels 3 and the inner surface of the inner skin of gypsum board panels 4. The cavity 5 of each external cavity wall 2 is then filled with concrete 18 from the top of the cavity wall 2 by a pump. After the concrete 18 has set the shuttering is removed and a skirting wall board 23 is placed adjacent the bottom of the gypsum board panels 4.

The concrete 11,14 of the foundation 10 may comprise bar (or British) reinforced concrete (BRC) which includes a mesh 23 of steel bars which may be is welded diagonally. This mesh 23 may also be in the cavity 5.

A roof 19 for the prefabricated building unit 1 comprises a precast concrete slab 20 and is placed on top of the concrete filled cavity walls 2. The slab 20 is supported particularly by the steel frame 6 in each wall 2 and rests on top of the inverted steel angle 9 of each wall 2. A layer of bitumen 21 for waterproofing is placed above the precast concrete slab 20 at a slight incline with concrete 22 beneath. The bitumen layer 21 may be 2 to 3 mm thick.

Referring to Figures 4 and 5, a modified prefabricated building unit 30 includes cavity walls 31 which each include an outer skin of cement board panels 32 and an inner skin of gypsum board panels 33. Block board or steel shuttering 34 is placed against the outer surface of the cement board panels 32 and the inner surface of the gypsum board panels 33. Holes 35 are made in the cement board panels 32 and the gypsum board panels 33 and tubes 36 span a gap between the cement board panels 32 and gypsum board panels 33 and are positioned between the adjacent holes 35. Battens 37 are placed on the outside of the shuttering 34 and they are fixed by nuts 38 and bolts 39 where the bolts pass through the holes 35 and tubes 36 so that the cement board 32 and the gypsum board 33 are held firmly and strengthened before the cavity 40 between the panels 32, 33 is filled. Concrete 41 is then poured into the cavity 40 and after it has set, the nuts 38 and bolts 39, battens 37 and shuttering 34 are removed. The holes 35 in the cement and gypsum board panels 32, 33 are made good and the wall 31 can then be painted. The bolting is particularly needed where a wider wall is required.

Referring to Figures 6 to 8, a wall frame 50 comprises a portion of a structural steel frame box 51 that forms the frame of another modified prefabricated building unit 52. The steel frame box 51 is designed to cope with structural forces comprising dead and live loads. These prefabricated building units 52 in the form of boxes can be placed alongside each other or stacked above one another to form a building. Such a prefabricated building unit 52 can contain doors 53, windows 54, electric wiring, plumbing and tiles. The boxes 51 are preferably 12 metres long and 4 metres width in order that they may be comply with traffic requirements when they are transported by truck to site. The site has a 10 to 20 cm deep concrete trench foundation to receive the boxed prefabricated building unit(s) 52 and the foundation has sufficient steel reinforcement to cope with the load of the building unit(s). The external cavity walls of the building units 52 are filled with concrete on site and fixings, such as steel strips, are used to connect the walls to the foundations.

In another embodiment illustrated in Figures 9 to 16, a prefabricated building unit 60 includes a plurality of external walls 61 which enclose a space.

Each wall 61 comprises a steel wall frame 62 comprising a grid of horizontal and vertical steei tubes 7, 8 and covered on one side by gypsum board panels 63.

The concrete foundation 64 (see Figure 11) for the prefabricated building unit 60 is prepared on site and initially comprises a trench 65 filled with concrete. An outer row 66 and an inner row 67 of lightweight concrete blocks with concrete 68 in-between are placed above the filled trench 65. Space within the inner row 67 of blocks is filled with compacted soil 69. A concrete floor slab is then installed above the rows 66, 67 of blocks and compacted soil 69.

The prefabricated building unit 60 is transported and installed on the foundation 64. A wall 71 of lightweight concrete stone blocks is constructed in relation to the gypsum board panels 63 50 that the wall 71 of blocks form an outer skin of the wall 61 and the gypsum board panels 63 form the inner skin of the wall 61. Hence, the wall 61 becomes a cavity wall. Steel connectors 72 are used to connect the wall 71 of blocks to the steel frame 62. The cavity 73 between the inner faces of the wall 71 of blocks and the gypsum board panels 63 forms an air gap which is 5 to 30 cm wide. Insulation (not shown) may be included in the cavity 73. Shuttering is placed against the gypsum board panels 63. The cavity 73 of the external cavity wall is then filled with concrete 74 from the top of the cavity wall 61. After the concrete 74 has set the shuttering is removed.

In a specific example of the above embodiment, the lightweight concrete stone blocks are 600 mm long, 100 mm wide and 200 mm high, the gypsum board panels 63 are 12.5 mm thick and the steel tubes 7, 8 are 40 mm x 40 mm.

The wall 71 of lightweight concrete stone blocks may be instead of brick or concrete blocks.

In a modification, the cavities 5, 40, 73 of the cavity walls 2, 31, 61 of the prefabricated units 1, 30, 60 are filled with fibre reinforced concrete such as that described in GB2134556 which is particularly effective at providing protection from explosive blast forces wherein the fibres form 4 to 5 percent by weight of the concrete and comprise CEMFIL® glass fibres or similar. A prefabricated building unit with the cavities filled with such fibre concrete will comprise fire resistant materials. The building unit may be used to form a shelter, bunker or house that provides protection from explosive blast forces. It may be placed by an airport runway.

In another modification, the cavities 5, 40, 73 may be filled with sand or it may be filled with any debris which may be in the vicinity of the site.

In a further modification, hardened steel plates are included in the cavity before the cavity is filled with sand. Such an arrangement would be particularly suitable for buildings that need to have protection from explosives and bullets such as check points. Referring to Figure 17, a steel or wood frame wall 90 has a layer of steel plates 91, 91' on the inner and outer surfaces of the wall 90 and the steel plates 91, 91' are 8 to 25 mm thick. The steel plates 91 on the outer surface are covered by cement board panels 92 and the steel plates 91' on the inner surface are covered by gypsum board panels 93. The distance of the gap between the cement board panels 92 and the gypsum board panels 93 is 20 to cm wide. Sand/debris 94 fills the frame 90 between the plates 91, 91'.

io Referring to Figure 18, the prefabricated building unit 100 may comprise a wood frame wall 101 having cement board 102 on an outer surface and gypsum board 103 on an inner surface. The lowermost portion 104 of the inner surface 102 of the wall 101 inclines away from the rest of the wall. The wood frame wall 102 is filled with sand and/or debris 105.

Referring to Figures 19 and 20, a unit 110 for strengthening an existing wall 111 comprises a vertical side 112 to be placed against the wall 111 and has an opposite side 113 that is inclined away from the vertical side 112 so that the base of the unit 110 is larger than the top of the unit 110. Sand bags 114 are placed inside the unit 110.

Whilst particular embodiments have been described, it will be understood that various modifications may be made without departing from the scope of the invention.

Claims

CLAIMS: 1. A method of constructing a building comprising the steps of: (a) providing a prefabricated building unit having a cavity wall comprising a first skin and a second skin with a cavity in between; (b) installing the prefabricated building unit on a site; and (c) filling the cavity of the cavity wall when the unit is installed on site.
2. The method as claimed in claim 1, including the step of providing shuttering for at least one of the first and second skins of the cavity wall before the cavity is filled and removing the shuttering after the cavity has been filled.
3. The method as claimed in claim I or 2, including the step of preparing a concrete foundation on site for the prefabricated building unit to be installed on.

0
4. The method as claimed in claim 1, 2 or 3, wherein step (a) includes providing the prefabricated building unit with a wall frame, the wall frame being O within the cavity of the cavity wall.
5. The method as claimed in claim 4, including arranging the wall frame to allow fill material to pass down through the cavity to permit filling of the cavity from a top of the cavity wall.
6. The method as claimed in claim 4 or 5, wherein providing the prefabricated building unit with a wall frame comprises providing the prefabricated building unit with a steel frame.
7. The method as claimed in claim 4 or 5, wherein providing the prefabricated building unit with a wall frame comprises providing the prefabricated building unit with a portion of a structural steel frame.
8. The method as claimed in claim 4 or 5, wherein providing the prefabricated building unit with a wall frame comprises providing the prefabricated building unit with a wooden frame.
9. The method as claimed in any preceding claim, wherein step (c) comprises filling the cavity with concrete.
10. The method as claimed in any one of claims 1 to 8, wherein step (c) comprises filling the cavity with fibre reinforced concrete.
11. The method as claimed in any one of claims 1 to 8, wherein step (c) comprises filling the cavity with sand. c\J
12. The method as claimed in any one of claims I to 8, wherein step (c) comprises filling the cavity with debris.
13. The method as claimed in any one of claims 1 to 8, wherein step (c) O comprises filling the cavity with ballasting material having a relative density of at least 1.4.
14. The method as claimed in any preceding claim, including providing insulation in the cavity.
15. The method as claimed in claim 14, wherein the insulation is provided in the cavity before the cavity is filled.
16. The method as claimed in any preceding claim, including providing steel reinforcement in the cavity.
17. The method as claimed in claim 16, wherein the steel reinforcement is provided in the cavity before the cavity is filled.
18. The method as claimed in any preceding claim, including the step of installing at least one metal plate in the cavity before the cavity is filled.
19. The method as claimed in claim 18, wherein the step of installing the at least one metal plate comprises installing the at least one metal plate of hardened steel.
20. The method as claimed in claim 18 or 19, wherein the at least one metal plate is installed so as to extend over substantially all of at least one wall of the prefabricated building unit.cxi
21. The method as claimed in any preceding claim, including the step of installing a roof unit on the prefabricated building unit.O
22. The method as claimed in claim 21, wherein the step of installing a roof unit comprises installing a precast concrete roof unit.
23. The method as claimed in any preceding claim, wherein step (a) includes having at least one of the first and second skins to comprise cement board.
24. The method as claimed in any one of claims 1 to 22, wherein step (a) includes having at least one of the first and second skins to comprise lightweight concrete.
25. The method as claimed in any one of claims 1 to 22, wherein step (a) includes having at least one of the first and second skins to comprise gypsum board.
26. The method as claimed in any one of claims 1 to 22, wherein step (a) includes having one of the first and second skins to comprise lightweight concrete and the other of the first and second skins to comprise gypsum board.
27. The method as claimed in any preceding claim, wherein step (a) includes providing the prefabricated building unit with an external cavity wall.
28. The method as claimed in any preceding claim, including covering the cavity wall with a decorative material.
29. The method as claimed in any preceding claim, wherein step (a) includes providing the prefabricated building unit with services accommodated within the cavity.cxi
30. The method as claimed in any preceding claim, wherein step (a) includes providing the prefabricated building unit with a plurality of cavity walls.O
31. The method as claimed in any preceding claim, wherein step (a) includes providing the prefabricated building unit with a floor.
32. The method as claimed in claim 31, wherein step (a) includes covering the floor with ceramic tiles.
33. The method as claimed in any preceding claim, wherein step (a) includes covering the cavity wall with ceramic tiles.
34. The method as claimed in any preceding claim, wherein step (a) includes providing the prefabricated building unit with a bathroom with a toilet, wash-basin and shower.