GB2028905A - Roof Construction - Google Patents

Abstract

A method of constructing a roof for a building comprises in erecting a plurality of pairs of columns 11, spanning a roof frame member between each pair of columns, providing a displaceable connecting 13 between each end of each roof member and its adjacent column, hauling means 16 being arranged to enable the roof framework to be raised, using the columns as guides, until the roof is at the desired height, whereafter the displaceable connections are secured in position on their respective columns as by bolting, welding or pivoting. <IMAGE>

Description

SPECIFICATION Roof Construction for Clear Span Roofs The present invention concerns building units and more especially the roof construction for clear span roofs.

In known constructions the columns are erected, the roof members mounted thereon and secured thereto. When the framework is in position the roofing material is laid and secured thereon.

The disadvantage of this type of construction resides in the fact that all the roofing materials have to be hauled to a substantial height and the roofing labour also has to work at this elevation.

An object of the present invention is to provide a system whereby the roofing work can be carried out substantially at ground level.

According to the present invention a method of constructing a roof for a building comprises in erecting a plurality of pairs of columns, spanning a roof frame member between each pair of columns, providing a displaceable connection between each end of each roof member and its adjacent column, hauling means being arranged to enable the roof framework to be raised, using the columns as guides, until the roof is at the desired height, whereafter the displaceable connections are secured in position on their respective columns. Conveniently, the roofing material is secured to the roof framework prior to the raising of the roof.

In one embodiment of the invention the displaceable connection comprises a hollow sleeve having a cavity of similar shape as that of the column but of a larger cross section to enable the smooth sliding of the sleeve on the column.

Sleeves of about two feet in length have proved suitable in practice. These are provided with top and bottom flanges to enable connection with cooperating flanges similarly provided at the end of each roof truss.

The columns can be of any suitable crosssection, for example round, square, C-shaped, Ushaped etc., the sleeves being of a similar crosssection but larger. In large buildings universal beams of I-cross section are used as support columns. In this case the sleeve can be of box shaped construction, the main load carrying parts of which are at the four corners and strapped together. Any material having a satisfactory strength can be used, for example, steel, aluminium, plastics material etc. If desired the sleeves can be interfaced with a protective material for smooth running.

In a preferred embodiment of the invention, the sleeves are provided with holes or slots near their upper ends to co-operate with similar apertures in the upper portions of the columns. When the sleeves carrying the roof framework are in their desired upper positions, the sleeves can be bolted through the corresponding apertures in the columns.

Pulleys may be provided at the upper ends of the columns over which cables can pass for the purpose of hauling the roof upwardly by means of small hand winches. Such winches can be placed at all or alternate columns. After erection, the pulleys and other lifting gear can be removed.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figs. 1 a and 1 b together form a perspective view of a roof structure during the course of construction and prior to lifting; Fig. 2 is a detail showing the erection of the column with the sleeve in its lowermost position; and Fig. 3 is a detail of a sleeve surrounding a column and attached to a roof truss.

In Fig. 1 four pairs of columns 11 are shown erected on a base 12 which may be formed of a reinforced concrete slab or individual concrete pads under each column. Sleeves 13 are shown associated with each column and attached each to a roof truss 14 and an eaves beam 1 5 at right angles thereto. Pulley units 16 are arranged at the top of alternate pairs of columns 11.

Fig. 2 shows a detail of the sleeve 1 3 positioned over the column 11 when the column is lying at a small angle to the ground against a pair of upright flanges 1 7 provided on a column base plate 1 8. After emplacement of the sleeve 13 over the column and of the pulley unit 1 6, if the column is destined to carry one, the column is swung into the upright position and its lowermost portion bolted to the flanges 1 7.

Each sleeve 13 has a pair of flanges 19 adapted to co-operate with corresponding flanges 20 provided at the end of each roof truss 14. Each sleeve 1 3 also has a flange 21, adapted to receive the end of an eaves beam 15, the flange 21 being on the face of the sleeve 1 3 which is at right angles to the flanges 1 9. The sleeves 13 also have a further flange 22, positioned on the same surface as the flange 21 but at a lower level, adapted to receive one end of a bracing member 23, the other end of which is secured to the eaves beam 1 5. inside columns 11 each have a further flange 21 a and a flange 22a placed on the surface of the sleeve 1 3 opposite the flanges 21 and 22 respectively; these are for the attachment of another eaves beam 1 5 and another bracing member 23. Where a pulley unit 1 6 is provided on the top of a column, a cleat 24 is secured to the column 11 to receive a winch 25. Optional gutters 26, 26a can be fitted to the eaves beam if desired, prior to lifting the roof to its final position.

After erection of the columns, sleeves and beams, roofing material 27 can be emplaced when the roof structure is substantially at ground level.

If roof insulation is required, the whole roof structure can be lifted to a convenient height so that workmen can work thereunder. When the roof is complete it is lifted to the final height by the winches and co-operating pulley units and the sleeves bolted or otherwise secured into their final positions at the top of the columns. The pulley units can then be removed.

In the drawings, the sleeves are shown bolted but the connection can be of any other equivalent means such as welding, riveting etc. In this way the sleeves remain an integral part of the roof framework structure after it has been lifted and secured in position.

Claims (9)

Claims

1. A method of constructing a roof for a building which comprises the steps of erecting a plurality of pairs of columns, spanning a roof frame member between each pair of columns, providing a displaceable connection between each end of each roof member and its adjacent column, subsequently raising the roof to a desired height and securing the displaceable connections in position on their respective columns.

2. A method as claimed in claim 1, in which each displaceable connection is mounted on its column prior to lifting the column into a vertical position and clamping the column to its respecrive base plate.

3. A method as claimed in claim 1 or 2, in which the roofing material is secured in position prior to raising the roof.

4. A method as claimed in claim 1,2 or 3, in which the roof is raised to an intermediate height to permit working on the underside thereof.

5. A roof structure comprising a plurality of pairs of columns, each column having a displaceable sleeve mounted thereon, each sleeve being connected to one end of a roof frame member and lifting devices being provided at least at alternate pairs of columns.

6. A roof structure as claimed in claim 5, in which each displaceable sleeve is connected to at least one end of one eaves beam.

7. A roof structure as claimed in claim 5 or 6, in which the lifting devices comprise a pulley removably mounted at the top of the column cooperating with a winch removably housed on the corresponding sleeve.

8. A method of constructing a roof for a building substantially as herein described.

9. A roof structure constructed and arranged substantially as herein described with reference to an as illustrated in the accompanying drawings.