Fibreglassed flat roof: what restoring paint to use?

[Eric The Viking]

I know a lot of us do building work from time to time, so I thought I'd ask:

I have a flat roof, roughly 4 x 4.5m. It's not leaking now, but it's not too well either because it's had a fairly heavy scaffold sitting on it for the last four months or so. In a few places it's lost the gelcoat (gone from grey to "natural" yellow resin colour), and it needs something protective before winter comes.

What should I do to protect it?

I've got an unopened 5l can of Flag's "Roofix" which looks very good, but one tin won't come close to covering the whole thing, and anyway would probably be rather too thick and lumpy to give a good finish. And the cost of getting in enough to do the whole roof makes me wonder about alternatives.

I could probably put more grey fibreglass topcoat on it (never done this before but have used fibreglass for other things), but I've no idea of cost compared to a roof paint.

Are there other paints that would protect the fibreglass, but cover better than Roofix? It doesn't get walked-on normally, so they don't have to be very abrasion-proof.

Suggestions welcome.

My first job this week when the weather improves is to clean it thoroughly (have started this already). I don't think the fibreglass is badly damaged, but it's obviously vulnerable.

E.

 

[Keith 66]

If it hasnt got chippings on it you could sand it down & re gel with Flo coat, this is just Gelcoat with a wax in styrene additive mixed in. This sits on the surface upon cure & excludes air thereby causing the gel to cure glossy.
This is usually what fibreglass roofs are painted in when they are done in the first place. Once you have painted it in something else you will be into regular painting.
Trouble is this time of year you are pushing it using gel as its getting too cold & damp.

 

[Eric The Viking]

Thanks, I wondered about that. I'll see what I can do.

Much appreciated, E.

 

[Keith 66]

Actually there is a way you can boost the cure of polyester resin & gel in cold conditions. Adding a percentage of cobalt accelerator to the resin & mixing it in well before you add the catalyst can allow it to cure down to very low temperatures.
Most resin & gel is sold pre accelerated, the reason for this is that if cobalt accelerator & peroxide catalyst are mixed directly an extremely violent reaction occurs even explosion. Some suppliers may sell you some winter boosted gel if you dont want to mix yourself.

 

[Albatros]

when I got cracks in my fibreglass flat roof I sanded around the cracks a bit and then used some fibreglass car bodywork repair filler from an old tin from Halfords. I worked it between the cracks as best I could and then sanded it smooth. I knew the RAL colour code for the roof so I then oreded a tester pot online and used that. That was 2 years ago and it still looks good.

 

[TFrench]

We use Scott Bader Crystic roof system for roofing repairs, its very good. You can get a keg of just the gelcoat - it goes quite a long way.

 

[devonwoody]

Eric the V, I see your signature finishes with that quote of Mark Twain, if he had been older when he finalised that quote he would have added and when I got older I would remember nothing.

Hope the roofing goes well.

 

[Eric The Viking]

Thanks everyone.

The weather has won (for the time being). There are no leaks yet, but I'll probably take the time ASAP to gently clean off as much as I can - it got covered in limewash and lime plaster over the summer, which is pretty alkaline and although I've swept it as clean as I can (dry), there's still quite a lot still on the surface.

As soon as we have a good run of dry wether I'll see about overcoating with good quality gelcoat, such as the Scott Bader stuff.

Cheers, E.