As a guide for deciding on firring height a minimum gradient of 80:1 is usually required. Using the drop down menus below please choose from our standard heights and gradients or enter your own heights and gradient. You can collect your firrings or have them delivered. The maximum firring length we can provide for collection is 12m. We are restricted to 11.4m firring length if we are delivering. For help on how to use this calculator go to the bottom of the page.
|Quantity||Length||Thickness||Fall||Gradient||Weight||Firrings Price||Delivery Price.
|2 firrings with a fall of 36mm to 5mm|
over a length of 3000mm
cut from 1 pieces 3000mm
of 2"x2" nominal(untreated).
These firrings are 44mm thick.
||3000mm||44mm||36mm to 5mm
(Note: These sizes are not exact
and are usually to within 2mm.)
See map below.
The map below is colour coordinated to additional delivery surcharges for your area.
Quantity of firrings
When we cut firrings from our stock timbers we get 2 firrings per piece. If you order an odd number we will charge you for the next even number up. If delivery is needed then it would be cheaper to order exactly what you need as delivery cost is based on weight. The spare firring would be discarded in this case.
Length of firring
We will cut to length but we will charge for the nearest stock length. Our stock lengths are 2.4m, 3.0m, 3.6m, 4.8m and 6.0m which may vary depending on what section you require. Firrings less than 4.8m they will be supplied one piece. Firrings greater than 4.8m will be supplied in two halves
There is no structural reason why 69mm should ever be used for a flat roof but we have included it anyway in case matching up to 69mm joists is desired. Delivery will cost more for the 69mm due to increased weight.
Treatment of firrings is not needed for flat roofs but we have included it just in case it has been insisted upon. Treatment is only available in the 44mm thickness. WARNING: treatment will be cut away from the tapered edge and maybe from the bottom edge as well.
When choosing your "Fall option" below please note we have a far greater range of timber sizes to use in the 44mm thick firring option which could result in less waste and cost.