The material that is used for flashing needs to be malleable,
so that it can be formed around the different contours of the roof.
This is where lead has proven the best, it can be formed easily into complicated shapes without tearing.
Tin, lead or copper
Valley flashing, if the dormer is a hip or gable roof, step flashing under the shingles which abutt the dormer walls.
They ARE used when quality and longevity is needed for leader lines, roof drain flashing material
Only if the builder wants the best possible quality installed
it is used around the edges of the roofactually, it's used in the valley's and anywhere the roof meets an outside wall... drip edge is used on the edges, except in areas where precautions must be taken against ice-dams.Flashing is also used where anything passes through the roofA windowA stink pipeA flueA chimney stackA vent from a cookerA vent from a bathroom with no outside window.A drain in a flat roofIt is used anywhere there is a protrustion in the roof. Flashing can also be found around hvac units, scuppers, etc...
There are two meanings for a roof aprona flashing material, similar to a drip edge, that is installed at the bottom of a roof, channelling the run-off away from the fascia and into a gutter;a flashing along the edge of a roof where it butts into a wall that goes higher than the roof. The flashing directs water away from the wall and onto the roof.
Step flashing is used in two applications on roofs. 1) Around skylights/roof windows (eg. Velux). 2) Around the base of chimneys.
Lead flashing was commonly used on chimneys, around other roof penetrations such as vent pipes, and roof junctions, such as valleys. It is still used for this, but is less common because of its cost, and the availability of alternatives. Modern alternatives: pvc, butyl rubber etc. are often less durable. It is used in sheets to create rain resistant junctions because it is soft and malleable and weather durable. The lead sheets are tapped with a rounded hammer around moulding shapes to conform to the shapes of the building they will be flashing. Because of the malleability of lead, these sheets can be shaped closely to awkward shapes, such as the junction of a sloping roof and a chimney, without the need for the sheet to be cut. Cuts in the sheet would create a potential leak site. Copper is also used for this purpose as it is also durable and malleable. It is usually more expensive than lead. Lead and copper should not be used in an area of roof where water is being collected for drinking water. Lead or copper should not be used where run-off water will flow onto Zincalume coated steel, as this will increase the rate of corrosion. This may also void a manufacturer's guarantee on the product.
how to do lead flashing around a small bay
You pay someone that knows how.
Prior to caulking the lead joint I use a level then pour the joint and tap each side of the lead so the drain does not shift then finish packing the lead and trim the lead with a trimming iron...same as for CI roof drains except roof drains are slightly counter sunk to allow for the 4 PSF sheet lead flashing
A drawing that would show how high the flashing and counter flashing is going to be on a roof plus the various penetrations and pitch pockets and leader lines and possibly a scupper
flashing is usually done with tin, nails, and roofing cement.. I suggest you go to Youtube and in the Search Bar type in "flashing A Roof"-- check out the insightful How -To -Videos.
The installing of flashing around roof tiles can be complicated and varies depending on the type of tiles, the flashing material, the conditions (weather etc. that it is exposed to) and the type of junction. To make sure it is done correctly, get drawings and information from the manufacturer of the tiles. Their method may need to be followed for any guarantees to apply. If the manufacturer of the tiles does not exist anymore or cannot be traced, look at traditional or similar examples. The flashing detail used may also need to comply with local authority regulations.
Copper or lead work best because it's easy to flash.The flashing is the metal that keeps the water from getting between the roof and the wall.
By removing all the membrane down to the original slab then primming the slab and using 4 ply 15# felt and hot applied bitumen making sure the roof has pitch to the drainage systems and using 4 PSF sheet lead flashing below the membrane
For when he has to haul over-dimension loads.
== == The roof material is lead.
Install the sill flashing first, according to the manufacturer's instructions. As a rule, flashings are nailed into the curb and sometimes cemented to the roof with plastic roof cement, but not nailed to the roof.
Flashing prevents rain get into the structure of the building
A dormer is a small piece of roof that projects from or is not in plane with the main roof plane. It has a junction with the main roof and this junction is where the flashing is required. Dormers can vary in shape, so the exact form of flashing required will vary. The type of flashing also depends on the roofing material, and whether the same material is on the main roof and the dormer roof. If the main roof plane and the dormer are of the same material, the flashing can usually be the same as used on a similar junction of the main roof. Important parts of a basic flashing are: * it laps from under the upper or higher roof cladding so that water will run down onto it from the higher cladding, and it laps over the lower roof cladding so that water running down it will run onto the lower cladding, rather than underneath the lower cladding. Flashings that run parallel to the fall of the roof are a little different but follow the same principle: look at the path the water will follow. * It is lapped a sufficient distance under and over the cladding to prevent water seeping back. This distance will depend on the roofing material, the material's profile, the strength of wind in the area and the rainfall of the area. * It may also need a return or kickback on the flashing to prevent capillary action or wind driven moisture. Flashing materials must be compatible with the roofing material. Water running over some materials will collect ions that may make materials that this water then runs onto be stained or corrode quickly.