Understand how our roofs are constructed and you’ll see for yourself why a fibreglass roof by Ace Roofing is the right way to get a roof that will last for decades and 20 year insurance backed guarantee.

Step 1:  New build or Replacement – you need to start on a good surface

18mm OSB 3 (humidity resistant)

A good fibreglass roof needs a quality substrate.  We only use 18mm OSB 3 (humidity resistant Oriented Strand Board) as the only roof deck substrate to give a durable and structurally sound surface.  The importance that backs our design choice is that it’s rough textured surface allows a mechanical and chemical fix between the building, the roof deck, and the fibreglass and resin.  Resin gets a really good grip to the material, and isn’t going to delaminate (peeling away from the surface of the wood).  Where possible we use tongue and groove sheets that are 2′ x 8′ long.  Tongue and groove gives a better finish and helps eliminate issues with natural contraction and

Tongue and Groove OSB 3

Tongue and Groove 18mm OSB 3

expansion.  It also doesn’t turn to weetabix if it ever becomes wet!  But we doubt that water will ever come into contact with it – in fact we guarantee it.


We either overboard or rip off and start again.  Our free site survey will identify the best option for you and the implications of either method including the necessity of warm roof construction where appropriate to comply with building control.

Step 2:  Pre-formed gutter and upstand trim installation

Example of a pre-formed fibreglass trim

The grey pre-formed trim is what you see when you stand on the ground floor looking up at your roof. The trim is covered in resin matching the colour of your roof.

Let’s face it – the parts of your roof you are going to see need to look really good.  Our workers are pedantic about detail and they spend the time necessary to ensure the best looking corners and trims.  Each trim is bandaged with resin and fibreglass for strength.

OSB 3 wood installation example

Roof substrate ready for fibreglassing




Our trims are pre-formed and offer a superb finish – each corner is carefully mitered to give a very aesthetically pleasing finish.  We have trims to suit every roof to fit gutters, upstands, valleys and more.  The trim is the part you’ll see from the ground.

Step 3:  The sticky part

Ace Roofing worker using resin

Our worker ensuring the fibreglass is correctly wet out

The lamination process is sticky, and a timer is ticking and chasing you through the process.  Once the resin is catalysed we have about 10-20 minutes to wet out the fibreglass.  The wetting out process is arguably the most important process and our team never catalyses more resin than they can properly wet out (we’ve fixed disasters by other contractors just on this part of the process!)

Correctly wet out fibreglass matting

Resin and fibreglass correctly wet out and ready for the UV protective top coat. The fibreglass is transparent at this stage.

When fibreglass is wet out properly it becomes see-through / transparent.  It takes skill and it takes years of experience to correctly perform this stage.  Do it wrong and you may as well start again.

Our lamination process is

  1. a layer of resin
  2. 1 or 2 (depending on usage) layers of thick chop strand matting
  3. another layer of resin
  4. occasionally an additional filler coat of resin
  5. sand back and apply coloured and UV protective top coat (see below)

Step 4:  What – more resin?  Yes …

Top coated roof

Top coated and finished roof. Our attention to detail really makes our roofs stand out from the crowd.

After sanding the newly fibreglassed roof we then apply a thick and UV protective layer of top coat in a colour of your choice.  Often this is grey in colour – but you can have whatever you would like.  Our workers at this point turn super pedantic – it’s the bit you can really see and they want it to look perfect.  Expect them to work on this endlessly until they have perfection!



Step 5:  20 year insurance backed guarantee

Our guarantee is underwritten by an insurance company.


The Confederation of Roofing Contractors seal – your assurance of a quality installation

In due course your guarantee and insurance policy will arrive – we offer this on every roof and the majority of our customers sign this off on the final quote.  A transferable guarantee held with an insurance company is the only guarantee worth having.



Step 6:  Write us a testimonial

Once everything is in order, insurance received, and roof weather tested we’ll ask you to rate our service with an independent body.  See what our customers have said about us here.  We are rated in the top 5 flat roofers in the country – at the time of writing we were actually 2nd! Our reputation is everything to us and independent reviews give you the perspective you need to choose the right contractor.