What should all cavity trays have?
Cavity trays must always be bedded onto fresh mortar. Weep holes must be provided in the external leaf of the wall to allow moisture to drain to the outside. Weep holes are generally created by omitting mortar from the vertical joint between bricks, typically at 450-900 mm centres.
How high should a cavity tray be?
150mm
A cavity tray should be provided 150mm above any adjoining roof or balcony surface. The tray should be lapped over any roof upstand or flashing to ensure water penetrating into the cavity does not enter the enclosed area.
Where is a cavity tray required?
Cavity tray best practice Cavity trays should be installed over all external door and window openings including bay windows and at roof abutments, both horizontal and pitched. The cavity tray should be correctly located directly over the window/door head.
How are cavity trays measured?
Calculating the quantity of horizontal cavity trays required is reasonably straightforward. Simply measure the overall width of the abutting roof, or width of the area where cavity tray protection is required, and divide this measurement by the effective length of the cavity tray component which you have chosen to use.
How high is a damp-proof course?
Damp Proofing Wall Regulations: DPC must be at least 150mm above the level of the adjoining ground if it is in an external wall. It must also be continuous with any damp-proof membrane in the floor (i.e. no gaps!)
How high is a damp proof course?
What is a tray damp?
5 Aug 2014. A cavity tray is a damp-proof course (DPC) that crosses the cavity of a cavity wall in order to prevent dampness from permeating the internal skin of a wall. A cavity tray steps up between the outer and inner leaves, to form a gutter which leads to a weephole in the outer leaf.
What are cavity wall trays?
A cavity tray is essentially a damp-proof course (DPC) that crosses the cavity of a cavity wall in order to prevent dampness from permeating the internal skin of a wall. Cavity trays are a unique range of single-element systems that are available off-the-shelf.
What is a Type E cavity tray?
The Type E Cavity Tray is a preformed DPC cavitray that is designed to be inserted into an existing cavity wall. The Type E only needs one course of bricks to be disrupted for successful installation, with just a few bricks removed at any time.
How do I know if I have damp proof course?
You can find your DPC by taking a look at the external wall. Look down at ground level and look up about 6 inches or so up the wall. Somewhere around here you will see a thin black line of either slate or plastic running horizontally across the brick work. This is your DPC.
What is a damp proof course?
What is DPC? The damp proof course (DPC) is generally applied at basement levels, which restricts the movement of moisture through walls and floors. The selection of materials for the damp proof course and its various methods of applications in buildings is discussed.
What is a preformed stepped cavity tray (DPC)?
Preformed stepped cavity trays should be provided above the roof surface and linked to the roof upstand or flashing to ensure any water penetrating into the cavity does not enter the enclosed area. A DPC should be provided behind a doorstep where it is higher than a wall DPC.
What are the requirements for cavity trays?
Cavity trays should: be in one continuous piece or have sealed or welded joints. The upstand part of the cavity tray should be returned into the inner leaf unless it is stiff enough to stand against the inner leaf without support.
Do I need a cavity tray on my roof?
A cavity tray should be provided to direct any water that enters the cavity to the outside. The cavity tray should fully protect the opening. A cavity tray should be provided 150mm above any adjoining roof or balcony surface.