GB2474543A

GB2474543A - Damp-proof course for a threshold

Info

Publication number: GB2474543A
Application number: GB201015053A
Authority: GB
Inventors: John Louis Shillabeer
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-10-15
Filing date: 2010-09-09
Publication date: 2011-04-20
Anticipated expiration: 2030-09-09
Also published as: GB201015053D0; GB2474543B; GB0918131D0

Abstract

An opening in a wall, particularly a cavity wall 10, 12, 14, has a threshold with an L shaped damp-proof course 32 having a horizontal base 34 that overlies the exposed portion of the outer skin 10 of the wall and a vertical portion (dotted 36 Fig. 2) that extends downwardly and lies adjacent the inner face of the wall portion, preferably the inner face of the outer skin 10 thus forming a U shaped channel. Preferably there is a second vertical portion 36 against the outer face. There may be short an upstanding channel portion 38, 40 at each end of the damp-course for engaging over the exposed end faces of the outer skin 10 at the sides of the opening. The damp-course may be manufactured from a unitary plastics moulding, for example containing polypropylene) or the one or both of the upstanding channel portions could be made separately to the channel/L shaped base portion. There may be a thermally insulating material bonded to the outside face of the vertical portion which lies within the wall cavity (72 Fig. 3).

Description

THRESHOLD CONSTRUCTION AND COMPONENT THREFOR

This invention relates to a building construction comprising the region of a threshold; to a component for use in such a construction, particularly to enhance damp-proofing; and to a method of building.

Thus in one aspect the invention provides a building construction comprising a wall, an opening in the wall with a threshold at the bottom, and a damp-proof course ("dpc") comprising an L-section having a first, generally horizontal, portion extending along the threshold, and a second, generally vertical, portion extending downwardly from the first portion and lying adjacent the inner face of a wall portion. Generally the wall is a cavity wall and the threshold is provided in or by the outer skin.

The second (generally substantially vertical) portion of the dpc may then lie adjacent the face of the outer skin in the cavity. A floor may abut the second portion of the dpc, either directly or via a layer of insulation, which may be attached to the dpc.

The dpc may comprise a channel having respective substantially vertical portions on both sides of the first portion, the channel embracing the upper region of the wall (generally the outer skin of a cavity wall).

At one end, and preferably at both ends, the dpc may have an upstanding portion for lying against the end face of the wall. The second portion or portions of the dpc may extend upwardly to form, with the upstanding portion, a formation that engages and preferably wraps around the end region of the wall. Thus a preferred type of embodiment employs a dpc that defines three channels: a longitudinal channel, open downwardly, for engaging over the upper portion of a wall at the bottom of the opening; and a pair of relatively short lateral channels, facing opposite ways, for engaging end regions of the upright wall portions delimiting the opening.

The dpc is suitably formed from a self-supporting plastics material, e.g. comprising polypropylene. There may be thermally insulating material bonded to the second portion and abutted by the floor when this has been installed.

The dpc may comprise a unitary moulding.

Alternatively it may comprise a longitudinal base portion and a pair of end portions that overlap the base portion.

Thus dpc's of different length can be provided by varying the degree of overlap and/or by choosing modular components from a plurality, e.g. comprising longitudinal base portions of different lengths. The overlapping portions may be bonded together.

When the dpc comprises a channel, its outer substantially vertical portion is initially exposed. It may be abutted by paving which will conceal some or all of it. Alternatively some or all of it may be removed (preferably leaving a small protective bedding lip). To facilitate this, a line of weakness may be provided, e.g. adjacent the first portion.

In a preferred type of embodiment, the dpc acts as a threshold dpc, and additionally extends downwardly over both the front face and the cavity face of the masonry.

At either end of the tray the protection rises, and wraps around the masonry. It thus encapsulates the threshold masonry so the transmittance of damp from the exterior skin inwardly is prevented, regardless of the manner in which the flooring is interfaced. This expands the design options and flooring options. Concrete, pre-cast and timber floors can be laid and insulated adjacent to the external leaf.

The dpc wraps vertically around the masonry at either side of the opening to prevent any pooling / wind-driven water permeating the protected surfaces.

Following installation of the frame and dependent on the sill profile, these end wraps may be trimmed, conditional on their functionality not being compromised.

In isolating one of the areas most susceptible to water ingress transference, the dpc permits abutting flooring, abutting insulation and dpc's / membranes to connect with an exterior skin that is isolated from dampness at the point of connection.

In a second aspect the invention provides a dpc for use in such a building construction, preferably of the form that defines three channels: a longitudinal channel, open downwardly, for engaging over the upper portion of a wall at he bottom of the opening; and a pair of relatively short lateral channels, facing opposite ways, for engaging end regions of the upright wall portions delimiting the opening.

In a third aspect the invention provides a method of building comprising building a wall with an opening in it, and installing a dpc according to the second aspect so as to produce a building construction according to the first aspect.

Some embodiments of the invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a perspective view, from the exterior, showing part of a building construction including a region where an opening with a threshold is being constructed; Fig. 2 is a perspective view of a damp-proof course tray included in the construction shown in Fig. 1; Fig. 3. is a sectional view through a building construction in the region of a threshold, including a damp-proof course tray, a timber sill, a floor slab, and insulation above the slab; Fig. 4 is a view similar to that of Fig. 3 but showing a construction having insulation below the floor s lab; Fig. 5 is a view similar to that of Figs. 3 and 4 but showing a construction with a concrete sill, and insulation below the floor slab; and Fig. 6 is a view similar to that of Figs. 3 to 5, but showing a construction with a timber sill and a timber floor.

The building construction shown in Fig. 1 includes a cavity wall having an outer skin 10, a cavity 12, and an inner skin 14. There is an opening 16 in the wall where end faces 18 and 20 of the inner and outer skins are exposed. The cavity 12 is closed by a "type H cavicloser" cavity closer (Cavity Trays Limited). The cavity closer 22 has an insulating section 24 that projects into the cavity 12, and a face plate 26 that lies against the exposed faces 18, 20 of the inner and outer skins. The insulated portion 24 has profiled slots 28, one being engaged by a projection on the face plate 26, and others being engaged by wall ties 30, one of which is shown.

Fig. 1 only shows the wall at one side of the opening 16, but the arrangement at the other side will generally be similar.

At the bottom of the opening, the outer skin 10 is somewhat higher than the inner skin 14. (This can be seen most clearly from Figs. 3 to 6.) This upstanding portion of the outer skin 10 is capped by a tray 32 constituting a damp-proof course ("dpc"). This tray is illustrated in isolation in Fig. 2. The main length of the tray 32 has the form of an inverted channel, with a horizontal base 34 and two longitudinally extending side walls 36. This channel overlies and embraces the upper part of the outer skin 10 within the opening 16. At each end, the horizontal base 34 leads to an upstanding wall portion 38. The side walls 36 likewise have upstanding portions 40 at the end, rising up above the level of the base 34 to the same extent as the upstanding portions 38.

These portions 40 together with the upstanding portions 38 define channels which engage over the exposed end face of the outer skin 10. The tray 32 is formed from a waterproof and water resistant material, suitably a plastic such as polypropylene. Thus it is able to act as a damp-proof course for the threshold region.

Once the tray 32 has been installed, construction work can carry on in a generally conventional manner.

Generally a sill will be installed on top of the tray, forming part of a door frame.

Fig. 3 shows a building construction including a foundation 60 from which outer (62) and inner (64) masonry skins rise, separated by a cavity 66. The outer skin 62 bears the tray 32 in the threshold region. A timber sill 68 lies on top of the tray 32, and extends across the cavity 12. The inner masonry skin 64 rising from the foundation 60 bears a concrete slab floor 70.

On top of this there is a layer of insulation 72. There is a further thin layer of insulation 74 on (and preferably adhered to) the vertical side 36 of the tray within the cavity. A further damp-proof course 76 is sandwiched between, on the one side, this further insulation 74 and the sill 68 and, on the other side, the slab 70 and its overlying insulation 72. This further damp-proof course 74 is tacked to the back of the sill 68.

Fig. 4 shows an arrangement substantially the same as that of Fig. 3, with the same components given the same reference numbers. The main difference is that, in the Fig. 4 construction, the main insulation 72 is below the concrete slab 70.

Fig. 5 shows a construction which is very similar to that of Fig. 4, with a concrete slab 70 on top of insulation 72. However in this construction, the sill 68 is also of concrete. In consequence the additional damp-proof course 78 is not tacked to it. To the front, paving 80 abuts the wall below the level of the sill 68.

Fig. 6 shows a construction quite similar to that shown in Fig. 3 except that there is a timber floor 90 on joists 92, with insulation 72 beneath the floor 90, between the joists 92.

Claims

CLAIMS1. A building construction comprising a wall, an opening in the wall with a threshold at the bottom, and a damp-proof course comprising an L-section having a first, generally horizontal, portion extending along the threshold, and a second, generally vertical, portion extending downwardly from the first portion and lying adjacent the inner face of a wall portion.
2. A building construction according to claim 1 wherein the wall is a cavity wall having inner and outer skins, the threshold is provided in or by the outer skin, and said second portion of the damp-proof course lies adjacent the face of the outer skin in the cavity.
3. A building construction according to claim 2 wherein a floor abuts the second portion of the damp-proof course, either directly or via a layer of insulation.
4. A building construction according to claim 2 or claim 3 wherein the damp-proof course comprises a channel having respective substantially vertical second portions on both sides of the first portion, the channel embracing the upper region of the portion of the outer skin of the cavity wall at the bottom of the opening.
5. A building construction according to any preceding claim wherein the damp-proof course has, at at least one end, an upstanding portion which lies against a vertically extending face portion of the wall.
6. A building construction according to claim 5 wherein the damp-proof course has upstanding portions at both ends.
7. A building construction according to claim 5 or claim 6 wherein the or each second portion of the damp-proof course extends upwardly of the first portion to form, with a said upstanding portion, a formation that engages the wall at one side of the opening.
8. A building construction according to claim 7 wherein the damp-proof course has second portions on both sides of the first portion, and both second portions extend upwardly of the first portion and form with the or each upstanding portion a channel that engages over the wall at a respective side of the opening.
9. A building construction substantially as described herein with reference to and as illustrated in the accompanying drawings.
10. A damp-proof course for installation at a threshold in an opening in a wall, said damp-proof course having a main portion that defines an elongate channel, open downwardly in use, for engaging over an upper portion of a wall at the bottom of the opening; and a pair of end portions located at the ends of the main portion and defining vertically extending channels, opening away from the main portion, for engaging end regions of the wall at the sides of the opening.
11. A damp-proof course according to claim 10 wherein the main portion and the two end portions are provided by a unitary plastics moulding.
12. A damp-proof course according to claim 10 wherein at least one of said end portions is formed separately from the main portion and is adapted to overlap it by an amount which is variable to vary the width of the damp-proof course.
13. A damp-proof course substantially as described herein with reference to and as illustrated in the accompanying drawings.
14. A method of building comprising building a wall with an opening in it, and installing a damp-proof course according to claim 10, 11, 12 or 13 so as to produce a building construction according to any of claims 1 to 9.