Ensure that valley boards plywood sheathing and tilting fillets provide full support for metal valley.
Pitched roof valley gutter detail.
Ensure that underlay is not laid under metal.
Roof ridges and ridge tiles roof hips and hip tiles roof valleys roof verges and lead flashings.
A valley gutter is where two main roofs meet or where there is a change in roof direction.
Fold the top over the roof ridge and cut the bottom along the drip edge metal.
Part 3 of the four part guide to roof construction covers pitched roof detail.
Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley.
Catchment area must be no more than 25 m gutter must be at least 250 mm wide.
Maximum catchment areas for valley gutters are given in table 8 of e2 as1 for minimum roof pitch and gutter widths.
How to do a roof valley martin s roofing and guttering merton ltd for all your roofing needs.
First clean the debris out of the valley including sawdust nails and whatever else is in there.
Cut tile and a half tiles neatly and fix to form a gap minimum 125mm wide centred on valley.
It is an area where water is directed towards rather than away from therefore correct detailing and construction is essential.
Cut underlay to rake and dress over tilting fillets to lap onto metal valley.
With a clean valley you can lay down some peel and stick roofing membrane.
Purpose made valley trough tiles should be supported by gutter boards where the roof uses single lap interlocking tiles they should be mechanically cut to the correct rake adjacent coverings should be neatly cut to form a smooth junction and preferably be cut from tile and a half tiles.
The lowest course of tiles slates should not touch the roof membrane.
A common misconception is that the mortar bedding is there to prevent water access.
Part 1 a guide to roof construction covers an overview of flat and pitched roofs.
Where a flat roof adjoins a pitched roof or where valleys or gutters occur the waterproof membrane should be carried up under the tiling to a height of 150mm above the flat roof valley or gutter and lapped by the roofing underlay.
The valley gutter problem areas can be made worse where there are surrounding trees and associated leaves and branches that can block the valley gutters up.
One of the areas of a pitched roof most prone to leakage if not constructed properly is the valley.