Some designs are using the up and down roof firring sometimes in 2x3 material with crosswise firring strips to provide a deep airflow channel so a lot of air flows from the bottom of the roof to the top ridege vent or ridge cupola thereby significantly reducing the heat transfer between the roofing and the sheathing in the warm hot months.
Furring strips behind siding.
The extra layer of insulation helps reduce thermal bridging through wood framing and the furring strips create a ventilation space behind the siding that promotes drying.
William costello is building a new house in southwest virginia that will be framed with 2x6s and will include up to 2 inches of exterior rigid foam insulation.
3 8 inch thick x 1 1 2 inch wide polypropylene furring strips attached vertically over air moisture barrier at face of each supporting stud to create capillary break between face of air moisture barrier and back of siding equal to cor a vent sturdi strips with sv 3 siding vent continuous at top and bottom by cor a vent inc.
An air space of even 1 8th of an inch will do the job so what you use as furring is really only a spacer and isn t too important as long as your siding can grab it or grab the sheathing behind with longer nails.
And increase your home s susceptibility to termites and wood rot.
Choosing the right furring strips is key to preserving a warranty for this engineered wood siding.
Trapped moisture behind siding can cause peeling paint rotting wood deteriorating house wrap siding to mold or mildew.
The first part of the system is the heavy duty sturdi strip furring strips which hold the siding away from the wall creating the necessary minimum capillary break 3 8 or 10mm that will allow moisture to drain away instead of becoming trapped.
Wall assemblies that incorporate rigid foam insulation over exterior sheathing followed by furring strips and siding are becoming common.
Furring strips for use behind sheet siding.
Installation details are key.
In order to install wood furring pre treated wood needs to be selected and each measured and painstakingly cut into the proper width and length.
The most important thing is that the material be consistent in size to avoid walls looking warped.
But writing in a q a post at green building advisor sonny chatum wonders whether this wall system often called a vented rainscreen is compatible with vinyl siding.