Refurbishing fibreglass oast cowls – what’s the story?

As professional oast cowl refurbishers, the word fibreglass (or GRP) can often strike a note of fear into our hearts. Commonly sold to oast house owners with an assurance of a maintenance-free lifespan, there’s definately a few potential pitfalls to consider before making the choice over a traditional wooden oast cowl (in our case made from hardy Russian or Scandinavian timber). Here goes…

Rusted fibreglass oast cowl


This little villain named rust is often to blame for the difficulty of refurbishing fibreglass oast cowls. After exposure to damp the fixings and bolts can rust solid, hindering any chance of maintenance.

Fungi in an oast cowl


Creeping under the fibreglass to cause all sorts of problems – in terms of oast cowls there’s nothing fun about fungi (sorry). Alongside making a mouldy mess it can also cause the cowls to discolour – making it near impossible to return to its glorious traditional white hue.

Maintaining fibreglass oast cowls

At Dude & Arnette we advise against refurbishing old fibreglass oast cowls due to their unpredictable nature. For example, we recently came to the rescue of Richard Budd whose fibreglass oast cowl had blown off the roof in stormy weather and bounced down the lawn, disintegrating as it went.

Arriving to check out the damage we could see the extent of the damp and mould that had crept under the fibreglass coating and eaten away at the cowl, causing it to weaken and eventually break off. We proceeded to reconstruct both the roof and cowl using the traditional methods that we’ve been perfecting since 1937, and Richard now happily reports that the mended oast kiln roof and new cowl has made the house warmer and cosier than ever. Pats on the back all round then.

Mould in an oast cowl

If you have a fibreglass cowl and are interested in how we could help to maintain it for you then please get in touch, we have extensive experience and can offer the best solution for you with the minimum disruption.
It may be that we advise to remove the cowl in order to be repainted and weatherproofed or even reconstructed but you can rest assured that a well-cared for oast cowl should only need maintenance every seven years or so, and our traditional methods will ensure the preservation of the traditional features of your home for decades to come.