10 Sep 2014

Firrings for flat roofs

What are firrings?

Firrings are used to create a fall on flat roofs. Firrings are cut through the length of the timber to create a slope when laid on top of roof joists for a flat roof before being covered with OSB or ply then finally felt.

Not many merchants cut firrings anymore. It takes time, experience and equipment which larger merchants often do not have. We regularly cut firrings in the mill at our Timber and Builders Merchant based in Deddington.

We cut firrings in pairs because this is less wasteful. Depending on the dimensions the firrings will be cut in identical pairs or a folding pairs.


How to order

When you order firrings for your building or DIY projects we will ask you for the following information.

1.  What length is your firring?     For example, 3.6m.

2.  What fall do you want?            For example, from 125mm to 50mm.

3.  How thick are your joists?       95% of firrings are 47mm which sit on 47mm joists.

How long will it take?

Every roof is different so there is no standard size for firrings. We cut all firrings to order and we aim to cut firrings within two days.


  • oxfordshire
  • deddington
  • firring
  • timber
comments powered by Disqus