GB2383344A

GB2383344A - Insulated integral damp proof and drain unit for use in a door threshold

Info

Publication number: GB2383344A
Application number: GB0130296A
Authority: GB
Inventors: Philip Harvey
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-12-19
Filing date: 2001-12-19
Publication date: 2003-06-25
Anticipated expiration: 2021-12-19
Also published as: GB0130296D0; GB2383344B

Abstract

A unit comprises an elongate base (1), a back wall (2) having insulation (4) attached thereto, side walls (3) and an extension projecting forwardly and downwardly from the base to form a 'laid to fit' drain (5). In use, the base is located directly below a threshold on a mortar bedding with the back (2) rising behind the threshold in a cavity of a cavity wall construction. Preferably the side walls (3) comprise detachable end caps and the insulated part (4) is attached to the back wall (2) by means of adhesive. The drain channel may be provided with reinforcing ribs (7) and an upturned lip (6).

Description

INSULATED THRESHOLD DAMP PROOF & DRAIN UNIT Background of the invention The invention relates to an isolating damp proof course and drain unit that is insulated and independent from the ground floor door threshold, for installation directly below ground floor thresholds.

Prior Art Traditionally a door threshold is raised above ground level, on the same level and protected by a traditional strip damp proof course, to prevent water ingress into the dwelling. In the United Kingdom the changes to the building regulations stipulate all new homes are to be built with a level threshold to provide easy access for disabled people (1995 building regulations incorporating approved document part'M'1999 edition, Access and facilities for disabled people).

The traditional level of threshold has had to change; consequently the level of damp proof course to protect the threshold has had to change so a new threshold damp proofing method would have to be adapted.

Technical Problem Traditionally a continues damp proof course (dpc) is essential at ground floor level to stop the upward movement of water, this dpc is laid in strip form, to the width of each leaf of a masonry cavity wall, traditionally split between the inner wall and outer wall of the cavity wall construction at the point of approximately 150mm above ground level.

The problems associated with a traditional ground floor level dpc were few when the threshold could be positioned on the same level as the dpc. The recent changes to United Kingdom Building Regulations (1995 building regulations incorporating approved document part'M'1999 edition, Access and facilities for disabled people) will cause problems with the traditional dpc when it runs into a ground level door threshold unit. Firstly, it is necessary for a ground level door threshold to be positioned at a lower level than the strip dpc course. Secondly, it is necessary for the door threshold to bridge the cavity. Both problems can cause water ingress and thermal bridging of the cavity wall construction.

Solution of the Invention An object of this invention is to form an under cap to a traditional door threshold that is an insulated and independent damp proofing and drain unit that comprises an elongate unit having two ends, an insulated back side wall, an elongate base and an extension that projects downward and outward from the elongate base to form a'laid to fall'drain channel.

Advantages of the Invention The use of a separate insulating damp proofing and drain unit on a ground level threshold has many advantages. Firstly, the level door threshold will be isolated and independent of the traditional strip damp proof course, this will prevent water ingress into the dwelling by the two ends of the unit preventing penetrating water running sideways and beyond the threshold area, the insulated back upstand will prevent thermal bridging and penetrating water passage through the back of the threshold into the internal floor screed and the elongate base will prevent upward movement of water. Secondly, the inclusion of an attached, but external'laid to fall'drain channel

will prevent wind driven water tracking below the threshold dpc and prevent pooling of water to the entrance of a dwelling, without the use of a secondary unit, by means of trapping any water running from the door threshold or ramped access and direct it away from the threshold area. The'laid to fall'drain channel is designed to sit below ground level under a ramped access with a feed from a 10-15mm gap between the ramp and threshold.

Description of preferred embodiment A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which: FIGURE 1. Shows an isometric view of the Insulated threshold damp proof and drain unit.

FIGURE 2. Shows an exploded view of the same unit as Figure 1.

FIGURE 3. Shows an end elevation view of the same unit as Figure 1.

An Insulated damp proof and drain unit, as figure 1,2 & 3 for providing an under cap to a traditional door threshold that is an insulated and independent damp proofing and drain unit that comprises an elongate unit having two ends 3, an insulated back 4, a back side wall 2, an elongate base 1 and an extension that projects downward and outward from the elongate base 1 to form a'laid to fall'drain channel 5. The unit is preferably formed from polypropylene or similar plastic materials or moulded from glass reinforced plastic but can successfully be manufactured in thin sheet metals (any metals should be coated with a satisfactory agent to prevent corrosion). The resulting product should be strong, lightweight, and aesthetically pleasing.

The elongate base 1 is situated directly below the threshold, situated directly onto a masonry bed with a preference of bedding on a thin even bed of mortar, with the backside wall 2 and insulated back 4 rising behind the threshold in the cavity of a cavity wall construction.

In the present embodiment the two ends 3 are detachable from the threshold damp proof and drain unit to allow flexibility in size. The length of the unit is preferably manufactured at 1000mm to suit most new door sizes with additional, to trim to size on site, the two ends 3 can be applied to the unit with the use of attached sealing agent to form a water tight seal and an isolated damp proof unit.

The insulated back 4 is manufactured to the length of the damp proof and drain unit and can be attached by the means of contact adhesive, the insulated back is preferably manufactured from a host of insulating mediums, in the present embodiment, polystyrene is shown at 40mm, but other mediums can be used depending on final insulation U value properties required.

When installed, the drain channel 5 is formed as a deep layed to fall design external to the cavity wall construction and built into a cleared area and back filled adjacent to the door threshold and positioned below the proposed ramped access, the ramped access should end between 10mm and 15mm short of the door threshold to allow

J water to drain from the threshold into the drain and in turn vent the drain and allow the drain to be cleaned/cleared of debris. The drain channel will have vertical reinforcing ribs 7 and turned up stand 6 to add strength to support ramped access.

The continuation of a damp proof tray/drain channel 9 will eliminate the need for 'dressing in'and/or'lapping in'of secondary dpc's to a secondary drain unit resulting in a watertight design.

In an alternative embodiment (not shown) the backside wall 2 can be supplied down wards at 90 degree (90 degree vertical as shown) with an insulation back 4 attached in order to fit other optional threshold designs, and the invention can be manufactured in a wide option of cross sectional design variations (not shown).

Claims

CLAIMS 1. An insulated threshold damp proof and drain unit situated in a cavity wall construction assembly that has been bridged by a ground level door threshold, for installation below such door threshold, said insulated threshold damp proof and drain unit having an elongate base having two end caps, an integrated extension that projects downward and outward from the elongate base to form a laid to fall drain channel and an insulated back side wall.
2. An insulated threshold damp proof and drain unit as claimed in Claim 1 where the laid to fall drain channel is a continuation of the threshold damp proofing elongate base.
3. An insulated threshold damp proof and drain unit as claimed in Claim 1 plus Claim 2 where the laid to fall drain channel has vertical reinforcing ribs and a turned over lip on the up stand to aid support of ramped access.
4. An insulated threshold damp proof and drain unit as claimed in any preceding claim where the elongate base and insulated back side wall can be cut to length of required door threshold.
5. An insulated threshold damp proof and drain unit as claimed in any preceding claim where an insulation batten is securely fixed to the rear of the back side wall to prevent cold transmitting to the Internal floor screed via the door threshold.
6. An insulated threshold damp proof and drain unit as claimed in any preceding claim where said insulation batten is securely fixed to the rear of the back side by means of adhesive.
7. An insulated threshold damp proof and drain unit as claimed in any preceding claim where said insulation batten is modified in density and thickness to comply with required U value characteristics.
8. An insulated threshold damp proof and drain unit as claimed in any preceding claim including a detachable end cap arrangement, when said end caps are subsequently secured in place, an isolated unit is formed to prevent water collected in the threshold unit from reaching the internal structure.
9. An insulated threshold damp proof and drain unit as claimed in any preceding claim where the end caps have sealing tape pre-applied to enable attachment to said insulated threshold damp proof and drain unit.
10. An insulated threshold damp proof and drain unit as claimed in any preceding claim, which is made from various plastics or metals or from a combination of these materials.
11. An insulated threshold damp proof and drain unit substantially as herein described and illustrated in the accompanying drawings.