450mm wide code 4 lead should be used turned back at the edges.
How to build a lead roof valley.
Installation procedures differ depending on the roof type and materials used.
The three methods to shingle a roof valley.
We will look here at the basic installation of an open lead lined roof valley.
The overlaps should be 150mm minimum and the only fixings should be a few copper nails under the overlaps.
This should be laid in two 1500mm lengths with a third length at the top.
Framing a complex roof is one of the trickiest parts of home building.
This roof valley is a perfect example.
In these circumstances it may be possible to just leave the existing valley base in place and replace only the cement.
Iko recommends that you install architectural shingles with the open valley method for the best roof performance.
But it doesn t have to be.
It is therefore worth asking the valley manufacturer for guidance on this.
Check the entire roof valley carefully to locate the source of these problems.
This recommendation includes iko s premium shingles.
When deciding how to shingle a roof valley you will need to consider your materials the climate and the desired look of the roof.
The roofing nails are fine so long as the lead of the roof valley is intact but once it starts to crack or fracture due to water pressure corrosion or other damage the nail provides a space for water to run into the home.
There are occasions when a roof valley is in good condition but the cement holding the tiles in place has washed out or crumbled.
If you begin with accurate as built measurements and use a construction calculator to do the math you can cut all of the rafters for most roofs on the ground in just one shot.
A roof valley is basically a gutter set between two meeting pitched roofs.
Some grp valleys are sufficiently robust to enable them to be laid directly over the rafters rather than being supported on valley boards.