They re installed before the tile is laid on the roof and may serve more than one purpose.
Replacing timber roof battens.
For example elevated battens are standard wood battens that have a block of plastic in some cases wood attached to the underside to elevate.
Thanks edward for allowing me to share our correspondence on this frequently asked question.
Can a metal roof be installed over my existing shingles without the use of battens.
They are made from fsc or pefc certified timber and manufactured to provide a consistent thickness of 25mm.
Quality battens are increasingly seen as an important part of forming a secure roof.
Roof battens are not just to provide footholds for roofers but are an important part of the roof structure itself.
Here is an example of improper installation with wood battens installed directly on top of the tar paper.
Roof battens are thin strips of material that may be made of wood plastic or metal.
They take the loads imposed by slates or tiles as well as loads from snow and wind.
While roof battens are most commonly made of metal or wood they can be made of other materials like plastic or composite there are several different types of batten some combine two materials to get the needed affect.
This great question comes from edward c a homeowner who plans to have a new metal roof installed over the aging existing shingles on his single story home.