GB2252990A - Radon sump - Google Patents

Abstract

A radon sump which can be installed easily by unskilled labour and which is cheap to produce comprises a unit in the form of a box-like housing having one or more walls 54, a floor and a roof 50, and is preferably made from a synthetic plastics material, optionally reinforced with glass fibre or other reinforcing material, the housing having a plurality of inlets 60A in its wall or walls and at least one outlet leading to a pipe spigot 56 which is made in one piece with the housing. Alternatively, the housing is made in concrete, in 3 pieces (floor, wall, roof) with a knock-out portion which can be removed for insertion of an outlet pipe. <IMAGE>

Description

RADON SUMP This invention relates to a radon sump.

Radiation from radon gas emanating from the ground and seeping into dwellings and other buildings poses a threat to the health of the occupants of those buildings, particularly in areas where the bedrock contains relatively high levels of uranium. One approach to counter this danger is the provision of a so-called radon sump immediately beneath a sealed slab forming the ground floor of a building. Radon seeping up through the ground beneath the floor tends to collect in the sump. It can be vented to the exterior using a suction pump if desired.

Up to now, radon sumps have been custom-built from bricks and mortar. Their construction has involved time and expense.

It would be desirable if there were available a radon sump which can be installed easily by unskilled labour and which is cheap to produce.

According to the present invention, there is provided a radon sump comprising a box-like housing having one or more walls, a floor and a roof, the housing either being made in one piece or in two or three parts such that it can be assembled to form said housing, the housing having a plurality of inlets in its wall or walls and at least one outlet leading to a pipe spigot which is made in one piece with the housing.

The box-like housing may have a single wall defining its periphery. That is, the housing may be circular or oval as seen in plan, while being rectangular or square as seen in side elevation. The roof and floor of the box-like housing are preferably flat and may be concrete slabs. Alternatively the housing may be of square or rectangular shape, having four walls, roof and floor preferably all made in one piece. All these parts are preferably made in a single operation from reinforced synthetic plastics.

According to a preferred feature of the invention, the pipe spigot, or at least one of the pipe spigots, is angled so that its axis extends downwardly at an angle of, e.g. 100 to the horizontal. This is a useful factor because it ensures that outlet pipes connected to the boxlike housing have an adequate fall. The housing preferably has several spigots and punch-out covers which block the pipe spigots. This is an advantageous arrangement because a single sump design can then be used in a variety of circumstances. For example, if foundations of the building or the presence of utility supply lines make it possible to run an outlet pipe only in a particular direction from the sump, one would leave the covers in place in the remaining pipe spigots and knock out only the cover from the spigot pointing in a direction clear of obstruction.

A further advantage of a sump according to an embodiment of the present invention is that its wall thickness is small compared to that of a conventional brick-and-mortar radon sump. Consequently to provide a sump of given internal volume, much less excavation is needed. For example, in a brick-and-mortar sump, the space occupied by the sump walls may be about 69% of the total excavated volume; on the other hand, with a sump according to the invention, to provide a sump of the same internal volume, the space occupied by the sump walls may be only about 11% of the total excavated volume. It will be understood that this represents an important cost saving in construction.

The invention will be better understood from the following non-limiting description of examples thereof given with reference to the accompanying drawings in which: Figure 1 is a horizontal cross-section taken on the plane A-A of Figure 2, showing an example of the invention in the form of a substantially square sump; Figure 2 is a front elevation of the sump shown in Figure 1; Figure 3 is a perspective view of the sump shown in Figures 1 and 2; Figure 4 is a side elevation of the sump shown in Figures 1-3; Figure 5 is a front elevation of a second embodiment of the invention constituted by a sump of substantially circular form; Figure 6 is a cross-section taken on a horizontal plane B-B of Figure 5, showing the substantially circular shape of this version of the sump as seen from above;; Figure 7 is a partially broken away perspective view of a radon sump according to a third embodiment of the invention; and Figure 8 is a section taken along the line Il-Il of Figure 7 on an enlarged scale.

Referring firstly to Figures 1-4, the illustrated sump has a roof 50 and a base 52 all made in one piece with walls 54 so forming an integrated box-like housing. The illustrated sump is preferably made from synthetic plastics material optionally reinforced with glass fibre or other reinforcement. In alternative embodiments of the invention, however, the sump may be made of other suitable materials. As seen best in Figures 1 and 3, the illustrated sump has a substantially square configuration as viewed from above and is rectangular as viewed from the side. Four pipe spigots 56A-D extend outwardly from respective walls. Each spigot is closed off by a cover, formed initially integral with the box-like housing but provided with a peripheral line of weakening so that the cover can be broken out of any one or more of the pipe spigots. The covers are shown at 58.

As illustrated in Figures 1-4, each wall of the sump has holes therein to provide a means of ingress for percolating radon gas. As illustrated, the holes 60 are rectangular, but of course they could be of any desired shape. In the illustrated design of sump, there are upper holes 60A and lower holes 60B which permit escape of condensation. If desired, more than one cover 58 may be broken out, and a pipe for conducting away the contents of the sump may be connected to a selected one or more of the pipe spigots 56. It is a feature of the illustrated arrangement that the cross-sectional area of the upper holes 60A, in aggregate, substantially exceeds that of the lower holes 60B.This has been found to be an important feature of the design in that it enhances the ability of the sump to collect radon gas which has a tendency to accumulate just below a sealed floor panel constituting the ground floor radon barrier of the house or other building. As will be seen from Figure 1, the location of the pipe spigots is such that two (56A, 56C) are on a common axis which extends across the centre, as seen in plan, of the sump, whereas the other two pipe spigots (568, 56D) are on a common axis but are both displaced from the sump centre line. This arrangement is included to give the sump design versatility.That is, referring for the moment to Figure 1, if there were obstructions towards the rear of the sump which prevented pipe spigots 56A, 56B and 56D from being used for connection to one or more outlet pipes, then by rotating the sump through 1800 one would have the situation that the pipe spigots 56B and 56D would take up new positions where satisfactory pipe connection could be made.

As is best seen from Figures 1 and 3, the covers 58 are located at the outer ends of the pipe spigots 56.

A second embodiment of the invention is illustrated in Figures 5 and 6. The radon sump illustrated in Figures 5 and 6 is a box-like housing, made of reinforced synthetic plastics material, or other suitable material such as concrete, and is similar in design to the embodiment of Figures 1-4 except that the roof and base are both substantially circular.

In Figures 5 and 6, the roof and base are shown at 70 and 72 respectively, the substantially cylindrical wall is shown at 74, pipe spigots are shown at 76A-D, and removable covers (or covers which may be punched out) at 78. The sump as shown in Figures 5 and 6 has upper holes of rectangular shape 80A and lower holes also of rectangular shape 803.

Of course these holes may be of other shapes if desired.

A radon sump 1 according to the embodiment of the invention shown in Figures 7 and 8 comprises a box-like structure having a side wall member 2 precast in one piece from reinforced concrete and opposite walls constituted by separate concrete slabs 3, 4 which are at the top and bottom in use. The side wall member 2 is essentially in the form of a square. It has a series of crenellations or notches 5 along its opposite edges. These notches 5, together with the slabs 3, 4 define inlet apertures for admitting radon to the interior chamber of the sump 1 in use.

Each side face of the side wall member 2 also has a region of reduced thickness constituting a punch-out portion 6 which can be removed to form an outlet aperture for connection to a ventilation duct (not shown) through which the radon collecting in the sump can be evacuated. In the embodiment illustrated in Figures 7 and 8, each punchout portion 6 has an inverted U-shape and extends about halfway up the side face of the member 2 from the lower edge in the position of use.

The outlet aperture opened up by the removal of a punch-out portion 6, is larger than an individual inlet aperture 5 but the total crosssectional area of all the inlet apertures is at least ten times greater than that of the one outlet aperture opened in use of the sump 1.

In both embodiments, the inlet apertures 5 are adjacent opposite edges of the respective side wall members 2, 12 rather than along a median line thereof. This is for ease of manufacture in the case of the precast concrete embodiment, whilst in the plastics embodiment the position of the apertures allows an optimum number of apertures to be formed without the strength of the side wall member 12 being compromised. Moreover, the apertures 5 and punch-out portions 6, on opposite sides of the sump 1, may be offset relative to each other or aligned with each other as appropriate.

In use, a sump according to the invention is placed in a substantially horizontal position in the substrate immediately below the level at which the ground or lowermost floor of a building is to be laid, the sump is entombed by the substrate and the overlying floor. Prior to the laying of the floor, a ventilation duct, usually connected to an extractor fan, is laid from an exterior wall of the building to the sump and the punch-out portion in the most appropriate orientation relative to the duct is removed to open up an outlet aperture for connection thereto.

The floor itself is then laid as a sealed slab or is sealed after laying, whereby any radon seeping up from the ground below cannot enter the building through the floor but rather is drawn into the sump from whence it is vented or evacuated to the exterior of the building for dispersal in the atmosphere.

The side-wall member 2 and slabs 3, 4 of the sump 1 of Figures 7 and 8 are usually kept in position by their own weight and by the constraint of the surrounding substrate.

A sump according to the invention for use in a private dwelling may have sides 600 mm long and a height of 225 mm. These dimensions may vary considerably in dependence on the size of the building to be served.

In a case where the radon sump according to any of the illustrated embodiments is made in concrete, it may be necessary, to facilitate the concrete moulding procedure, to construct the sump housing with a separate roof or base and attach this to the remainder of the sump before it leaves the factory, but after the concrete moulding has been completed.

Although not visible in the Figures, the pipe spigots 56A-D and 76A-D are constructed so that their axes are angled a few degrees downwardly from the horizontal plane, so that any straight pipes fitted thereto will have the necessary "fall" in order to facilitate clearance of condensation or radon gas or other sump contents.

Claims (11)

1. A radon sump comprising a box-like housing having one or more walls, a floor and a roof, the housing either being made in one piece or such that it can be assembled to form said housing, the housing having a plurality of inlets in its wall or walls and at least one outlet leading to a pipe spigot which is made in one piece with the housing.

2. A sump according to claim 1 in which the box-like housing has a single wall defining its periphery and precast slabs which form its floor and roof.

3. A sump according to claim 1 or 2 in which the roof and floor of the box-like housing are flat.

4. A sump according to claim 1 in which the housing is of square or rectangular shape, having four walls, roof and floor, these parts being made from a reinforced synthetic plastics material.

5. A sump according to any one of claims 1-4 in which the housing is circular or oval as seen in plan, and rectangular or square as seen in side elevation.

6. A modification of the sump according to claim 3 when dependent on claim 2 in which the pipe spigot is omitted and in which the single wall and the floor and roof slabs are made of precast concrete.

7. A sump according to claim 1 in which the pipe spigot, or at least one of the pipe spigots, is angled so that its axis extends downwardly at an angle of, e.g. 100 to the horizontal.

8. A sump according to claim 5 in which the wall has therein respective upper and lower series of holes, and the aggregate cross sectional area of the upper holes substantially exceeds that of the lower holes.

9. A sump according to claim 4 which is made in one or more moulding operations from a reinforced synthetic plastics material.

10. A radon sump substantially as herein described with reference to any one of the particular embodiments illustrated in the accompanying drawings.

11. Any novel combination or sub-combination of features disclosed and/or illustrated herein.