GB2486450A

GB2486450A - Water resistant dado board with moveable skirting and dado rail

Info

Publication number: GB2486450A
Application number: GB201021254A
Authority: GB
Inventors: David William Beddoes
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-15
Filing date: 2010-12-15
Publication date: 2012-06-20
Also published as: GB201021254D0

Abstract

A dado wall board forms a cavity against a wall with access into the cavity through apertures at floor level and higher up the wall thereby allowing the circulation of forced convective gas within the cavity to rapidly dry the wall substructure, the cavity may also house thermal insulation. The apertures for access are covered by a moveable skirting at floor level and by a moveable dado rail at the higher level. The dado board is of water resistant wall board material. The cavity can be flushed out to clean it and can be ventilated though the apertures.

Description

Dado Wall Board This invention relates to a method for forced convective drying of wall substructure.

Global warming has caused an increase in flood events over recent years. The Intergovernmental Panel on Climate Change (IPCC) expects, in the future, that heat waves, storms, droughts, fire and floods will all increase as a result of global warming. Many buildings become temporarily unoccupied as a result of flood damage. The amount of damage caused to a building in a flood event is proportional to the depth of floodwater and the time the building is subjected to the floodwater.

In the case of a short duration flood event, external resistance measures such as door guards' can prevent some floodwater from entering a building but they cannot be safely used when floodwater depth exceeds 600mm because of the risk of structural damage. When the differential height between building floor level and the height of the floodwater is over 600mm the hydrostatic water pressure can cause structural damage to the waIls of the building and so the floodwater must be allowed to enter the building. Once the floodwater has entered the building the owners must wait for the floodwater to recede before beginning the cleaning and drying process to allow reoccupation. Cleaning the building is relatively easy but drying out a building after floodwater has entered is a major problem. Typically, the type of construction that needs drying out comprises sand/cement screeds, thick masonry walls, wooden skirting boards and gypsum plaster. Very often the gypsum plaster becomes damaged by the water and also contaminated by floodwater contents and so has to be completely removed. The wall substructure must then be dried out before re-plastering and then the new plaster has to dry out. Drying of wall construction takes a long time and whilst being dried the building has to remain unoccupied e.g. typical masonry construction dries at the rate of 1mm per day so that a 300mm thick wall takes ten to eleven months to dry out.

Statement of invention

To overcome this, the present invention proposes a dado wall board that forms a cavity against the wall substructure, an aperture at floor level allows access into the cavity for forced convective gas that constrained within the cavity passes directly across the surface of the wall substructure before exiting the cavity through another aperture part way up the wall.

Advantages The dado board is made from waterproof material and so will not need to be replaced when the building has been flooded.

The dado board will be mechanically fixed to the wall substructure so that it remains in place when immersed in floodwater.

A movable dado rail and movable skirting board will allow access into the cavity formed between the dado board and wall substructure and this allows both sides of a wall to be dried simultaneously.

Current drying methods comprise the removal of all the plaster on affected walls and then natural air drying whereby the wall substructure is dried with air circulated around the room to use natural drying potential, the process is very slow and weather dependent. It is a complex process involving consideration of room air temperature, relative humidity in room, moisture content of wall substructure and temperature of the wall substructure being dried.

An initial linear reduction of the wall substructure moisture content as a function of time the constant drying rate period' will give way to a falling rate period' and the time taken for drying increases accordingly, directly applied heated gas convection will decrease the constant drying rate period and lessen the falling rate'.

Forced heated convective gas is blown into the cavity at floor level and passes directly across the surface of the wall substructure to increase the driving force for heat transfer and accelerate drying.

Passing the heated convective gas intimately across the wall substructure also reduces air relative humidity that further increases the driving force for drying.

Passing the heated convective gas intimately across the wall substmcture will heat up the wall substructure and this higher temperature will speed up diffusion of water from the inside of the wall to the surface and so maintain a more continuous drying rate to accelerate the drying.

The convective gas exits the cavity at the top of the dado board and as such is at the required height for leaving the room via an open window, so forcing the convective gas through the floor aperture and up through the cavity and then out via a window can be a rapid, efficient, whole room convective cycle for accelerated drying as opposed to the typical slow drying due to room air that is heavily moisture laden and re-circulated around the room.

The installation of the dado board will look quite normal to the occupiers of the building. The dado board can be finished with waterproof plaster and paint, the movable dado rail and skirting will both appear as normal. There will be no visual stigma associated with the dado board installation.

After the cavity and wall substructure has been sanitised via the apertures and subsequently dried by forced heated convection the room can be returned to use simply by replacement of dado rail and skirting boards, there is no need for re-plastering.

The aperture formed between top of dado rail and normal wall covering can be set at any height required as long as it is above predicted floodwater heights.

Typically when waterproof membranes are installed in wall construction and the* floodwater is let into a building the floodwater manages to seep between the layers of construction. A film or layer of contaminated floodwater can become trapped between wall substructure and membrane and/or wall finishing materials and membrane, often this contaminated water cannot be removed without first having to remove the wall finish (plaster) and/or membrane.

The dado wall board system renders all this remedial work unnecessary because removal of dado rail and skirting allows sanitising fluid to be introduced via the dado rail aperture into the cavity between the dado board and the wall substructure. The rear of the dado board and the surface of the wall substructure can both be accessed and sariitised with sanitising fluid flushing down the cavity and passing under the floor membrane to the sunip/pump unit so that it can be pumped out of the building.

When floodwater levels are below 600mm the cavity formed between the wall substructure and the rear of the dado wall board will collect any floodwater that passes through imperfections or faults within the wall at a higher level and ensure it falls downwards to the floor membrane for subsequent removal by the sump/pump unit.

The cavity formed behind the dado wall board can be used to house wail insulation. As part of the dada wall board installation the building could be upgraded and fitted with wall insulation e.g. a closed cell insulation could be inserted behind the dado wall board and removed for cleaning via the dado aperture in the event of a flood.

Qrawings An example of the invention will now be described by referring to the accompanying drawings: Figure 1 is a cross-sectional drawing to show the dado wall board fitted to a building and the floodwater has been allowed into the building.

Figure 2 is a cross-sectional drawing to illustrate the sanitising process of the wall structure after the floodwater has receded.

Figure 3 is a cross-sectional drawing to show the drying process of the wall structure after it has been sanitised.

Dtailed description

Figure 1 is a cross-sectional drawing to show the dado wall board W. The drawing shows a building where the floodwater has reached a level that may cause structural damage and so the floodwater has been let into the rooms of the building. The level of floodwater inside the building shown as T is now the same as the floodwater level on the outside of the building.

The wall substructure shown as 0 is in this case masonry construction. The hole M is drilled through the inner skin of the wall to drain water from the centre of a solid wall or from a wall cavity. The waterproof dada wall board W is mechanically fixed to the wall substructure.

There is a removable or movable dada rail U fitted into or covering the aperture between the top of the waterproof dada wall board and the conventional wall board it The aperture at the bottom of the dado wall board is covered by the skirting board D that is fitted to the dado wall board at B and the building floor at E. The floor covering P is laid over a floor membrane F that sits on floor construction H. The floodwater shown at level T fills the rooms within the building and the cavity formed between the surface of the wall substructure and the rear face of the waterproof dado board W. Figure 2 is a cross-sectional drawing to illustrate the sanitising process of the wall structure after the floodwater has receded. The dado rail U is removed and aperture V allows access into the top of the cavity, similarly the skirting board is moved or removed to provide the aperture between dado wall board and floor for access into the cavity between wall substructure and dado wall board. Sanitising fluid C is introduced with applicator A into the cavity. Sanitising fluid is flushed into the cavity, as shown by arrows K, and completely cleans the cavity area including the surface of the wall substructure, the rear of the dado wail board and any mechanical fixings in the cavity. The used sanitising fluid exits the cavity at L and passes under membrane F to a sumpipump unit for removal from the building. The dado rail and the skirting board can be movable or completely removable, all that matters is that access can be gained into the cavity by the apertures above and below the dado wall board.

The existence of the cavity and access into it makes it possible to sanitise and rapidly dry the structure, a waterproof membrane could also be incorporated into the wall construction but such a membrane must be of adequate profile and its location must be carefully considered so that it can be accessed for sanitising and drying i.e. the waterproof membrane if installed must not be able to harbour an inaccessible trapped layer of contaminated floodwater within the wall.

Figure 3 is a cross-sectional drawing to show the drying process of the wall structure after it has been sanitised. The forced hot convective gas S is entering the cavity via the lower aperture after the skirting has been moved. Some gas will enter via holes M to dry the wall and/or the wall cavity but the majority will travel up the cavity between the wall substructure and the rear of the dado wall board drying out the wall substructure and exiting through aperture V which is part way up the wall where the dado rail has been removed. The moisture laden gas leaving the cavity through aperture V is at a convenient height to then pass out of the building through an open window and set up a whole room convection cycle for accelerated drying. After drying out is complete the cavity can have any insulation replaced behind the dado wall board by access through the apertures before the dado rail and skirting are refitted.