GB2575773A

GB2575773A - Roof aperture surrounds

Info

Publication number: GB2575773A
Application number: GB1809330.2A
Authority: GB
Inventors: Boyt Paul; Boyt Alan
Original assignee: Nicholson Sts LLP
Current assignee: Nicholson Sts LLP
Priority date: 2018-06-06
Filing date: 2018-06-06
Publication date: 2020-01-29
Also published as: GB201809330D0

Abstract

A plurality of kerb section wall units 3 assembled together to form a boundary kerb or wall structure, each unit having means to attach the unit to the upper surface of a flat roof and to attach each unit to adjacent units, each unit consisting of a box-like structure formed of a metallic outer skin and being filled with thermally insulating material. The metallic outer skin may be formed of a C-section member whose edges are attached to a flat plate via a non-heat transmissible material or thermal break formed of a strip of thermally insulating plastics 16. Each unit may have a flange 11 extending from one edge to enable fixation to a flat roof. Also claimed is a roof aperture surround formed of a plurality of the kerb section wall units connected to one another by straps fixed as bridges between the inner walls of adjacent units. the external and top faces of the surround may be covered by a water impermeable or waterproof membrane 6. The metallic outer skin may be aluminium.

Description

ROOF APERTURE SURROUNDS

This invention relates to roof aperture surrounds for use in building and construction and for location around apertures in usually horizontal flat roofs.

In many buildings constructed with flat roofs, the roof area may have one or more apertures in it, for example to enable pipework or ducting to pass through the roof between plant or equipment mounted on top of the flat roof and plant or other installations within the building itself. Another example is when access from within the building to the roof area is desired to enable work to be carried out on the roof or to enable access for other purposes.

It is common practice to mount mechanical plant such as air-conditioning units, chillers and solar energy capture devices on roofs, and these need to be connected to equipment within the building.

It is important to prevent rain water or melt water entering in the building via such an aperture. In order to avoid this, it is well-known practice to surround the aperture with a kerb or upstand, the external periphery of which is customarily covered with a waterproof membrane being usually an extension of the waterproof membrane sealing the roof itself against ingress of water.

Construction of such a kerb is carried out, in the case of a cast concrete roof, by casting the roof itself about a former shaped as desired and slightly larger than the eventual aperture and through which reinforcing bars which will be set in the concrete project a short way from the edges of the aperture formed when the concrete sets. After the concrete has set, it is necessary to cast a concrete kerb using customary form work to define an annular channel of shape corresponding to the aperture and where the projecting ends of the reinforcing bars are near the base of the channel. Concrete is then poured to the desired level in the channel and left to set. Once setting has been achieved, the formwork can be removed and subsequent customary finishing activities, which often include the application of a heat insulating material to the exterior of the kerb, can be carried out.

This procedure to provide an in-situ cast concrete kerb requires substantial expenditure of time and labour which is undesirable.

We have now found that effective kerbs or upstands can be installed quickly and easily by the provision of a modular arrangement of wall units which can be assembled together to form a complete surround and where the individual wall units can be simply fixed in position on the surface of the flat roof prior to the provision of a waterproof membrane sealing the entire structure against ingress of water.

The present invention accordingly provides a plurality of kerb section wall units which may be assembled together to form a boundary kerb or wall structure, each unit being provided with means to attach the unit to the upper surface of a flat roof and to attach each unit to each adjacent unit, and where each unit consists of a box-like structure formed from a metallic outer skin and being filled with thermally insulating material. Preferably the metallic outer skin is formed of a C-section member and a flat plate member and means are provided to attach the flat plate member to the edges of the Cshaped member but via a relatively non-heat transmissible material. The non-heat transmissible material constitutes a thermal break between the two portions of the thermal insulation-containing box-like structure. Because of the thermal break, the conduction of cold from the outside to the inside of the interior of the finished aperture is limited and will not give occasion for condensation of water vapour arising within the building to any material extent, even if the external weather conditions are sufficiently cold, and possibly wet and windy, such as to cool the exterior of the kerb or upstand substantially.

The way in which the individual sections are fixed to the roof is preferably by providing each of them with a flange extending from one edge which may be fixed to the flat roof surface using conventional means, for example by drilling holes in the roof surface and bolting the individual sections down using expansion bolts.

The units may conveniently be connected to one another by means of simple straps which are fixed as a bridge between the inner walls of adjacent sections.

The roof aperture surround system according to the present invention provides a number of advantages. In particular, once the dimension of the intended aperture is known, as well as the desired height of the upstand or kerb above the surface of the roof, a set of units may be manufactured off site and then delivered in disassembled form to the site as and when required. A soon as the roof with an aperture has been constructed, the individual units can be fixed to the top of the roof, fixed together and the surround left in place fixed to the roof ready for subsequent finishing. Installation is substantially quicker than pouring concrete into a mould, and there is no setting time. By using wall unit sections as described above, the kerb or upstand itself has much improved thermal insulation capacity compared to a concrete upstand, and the normal step of applying thermal insulation to the exterior of the concrete upstand is avoided.

The weight of the unit is also substantially less, so reducing the stress on the roof and its associated support structure in the area around the aperture.

The invention is illustrated by way of example with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic perspective view of a roof with an aperture in it surrounded by a kerb constructed in accordance with the invention;

Figure 2 is a vertical section through one edge of the aperture;

Figure 3 is a part-vertical section on an enlarged scale showing the connection between the roof structure and the kerb unit;

Figure 4 is likewise a section on an enlarged scale showing the top of the kerb;

Figure 5 is a diagrammatic section of a kerb component; and

Figure 6 is an exploded view of a single wall unit.

Referring to the drawings:

Figure 1 is a diagrammatic perspective view of an installed aperture surround in accordance with the invention. The surround is installed on top of a flat concrete roof which has had an aperture 2 cast in it. Fixed to the concrete slab 1 are a number of wall units 3, each of which is formed of a metallic skin, e.g. of an aluminium alloy and which is filled with thermal insulation material 4. As shown in Figure 1, the units 3 at the comers are mitred to provide a simple joint fitting system at each corner of the rectangular kerb formed by the units 3. As shown in Figure 1, a waterproof membrane 6 is laid on top of the concrete roof and it extends up the outer walls of the units 3 and across the top. In order to finish the roof and to provide adequate thermal insulation, a set of blocks of insulating material 7 are laid on top of the membrane 6 and spacers 8 are inserted into the top surface of blocks 7. The top of each spacer 8 is divided into four sectors, each receiving a comer of a set of paving blocks 9.

Figures 2 to 4 show the vertical section through one of the units 3. The units consist of an outer skin of aluminium, formed of two parts, a C-section portion shown on the right in the figures and a plate portion shown on the left. The base of the plate portion is bent at a right angle to form a flange 11. The plate portion is attached to the C-section portion by means of a plurality of rivets or low profile fasteners 12 so forming a stable rectangular box with open ends. The flange 11 may be held down on to the concrete roof by a set of expansion bolts 13 once holes are drilled in the appropriate positions around the perimeter of the aperture 2.

As shown in Figures 2 to 4, the water-impermeable membrane 6 extends over the heads of the bolts and across the top of each unit 3.

As can be seen in Figures 5 and 6, each unit 3 carries a number of joint pieces 15 attached to the metal skin, each one being connected by means of a simple penetrating screw fixing.

As can be seen in Figures 5 and 6, between the two portions of the metal casing, there is located a thermal break element, for example a strip of thermally insulating plastics material 16.

The specific embodiment described and illustrated above shows the surround on a concrete roof. However, the system may also be applied to roofs or roof decks of other construction, for example of metal or wood, where the advantages of low weight, offsite manufacture and quick installation are still achieved.

Claims

1. A plurality of kerb section wall units which may be assembled together to form a boundary kerb or wall structure, each unit being provided with means

5 to attach the unit io the upper surface of a flat roof and to attach each unit to each adjacent unit, and wherein each unit consists of a box-like structure formed of a metallic outer skin and being filled with thermally insulating material

10

2. A plurality of kerb section wall units in accordance with Claim 1 wherein the metallic outer skin is formed of a C-section member and a flat plate member and means are provided to attach the flat plate member to the edges of the C-shaped member via a relatively non-heat transmissible material,

3. A plurality of kerb section wall units in accordance with Claim 1 or 2 wherein each individual section is provided with a flange extending from one edge to enable the section to be fixed to a flat roof surface

20

4. A roof aperture surround formed of a plurality of kerb section wall units in accordance with any of Claims 1 to 3 where the units are connected to one another by means of straps fixed as bridges between the inner walls of adjacent sections.

25

5. A roof aperture surround in accordance with Claim 4 wherein the external surfaces and top surfaces of the surround are covered by a waterimpermeable membrane.