Tony K

Is there a market leader I can start with that you know of at all, and is it as good as (properly done) GRP?

Does anyone have any preference re tounge and groove or straight edge boards?

Here is the basic plan, nothing too complex. As @joe90 suggests, I was going to use pre-formed edges etc.

L shaped building with a split level roof, so basically two large separate rectangles each about 50m2. Only other complications are a series of small rooflights.

If that works then it's probably the best of both worlds. Are you thinking of doing the final top coat on each section as I go along?

That's useful, thanks. What size board are you thinking of for that sort of rate of productivity?

I'm in Epsom, Surrey. I'm not at the roofing stage yet. I have been delayed in getting out of the ground by the remarkably slow and poor performance of the mortgage lender and brokers - thats why I'm asking these questions about the roof; whereas I had planned to do the roofing in the clear, bright days of September, it now looks like a December job. I don't have a large shed. I was just thinking about that. I would need a fairly large, dry place to prepare the boards and let them dry. It might be that I could hire a gazebo for the purpose.

I was going to say that it sounds like I could pack my whole roof up and bring it to you, though I reckon the poor old Toyota Prius might strain a little if asked to carry a 100m2 roof. I presume the fully treated and coated boards would be screwed into place as per normal, with the screws going through the coating etc, but then being covered over by the subsequent strips?

Thanks. So even the topcoat can be done in stages? Would it not be stronger if done in one continuous operation? Don't suppose there are any good youtube videos around showing this technique? There are quite a few very useful ones showing the normal method and I would feel confident following them, but you're talking about next-level stuff!

That's interesting. If I am using 18mm t&g osb would I just literally apply a sheet of matting to each board, let them all go off, then fit them in place? Would I be against the clock once I begin applying the matting to the boards? I understood that it was better to get the topcoat on within a short time of the matting sheets?

Thanks chaps, good advice and understood. So my safest way is some sort of cover (scaffold being the best, and perhaps only viable option). If I were to decide to risk it without a cover, its not just a case of it not raining on the day. I need to ensure that the deck is thoroughly dry before I start. A feature of my design is that the roof is very simple to build. This is so that if, by that stage of the project, I need to save money I can do so by building it myself (with family roped in). This will take longer than if a roofer did it of course, and also mean that the deck is out under the weather for longer. I suppose I could build the deck, insert the grp edging forms and upstands, then if any of it gets wet place a ventilated polythene sheet over it all to dry out thoroughly whilst I wait for a couple of clear days to do the resin and topcoat?

Thanks. I completely understand the second bit! There seems to be some advice on a few grp manufacturers websites that if it starts to rain you should stop work and pull a rain cover over the area. It doesn't say that rain is anything other than a bad thing, but it also doesn't describe rain as fatal. I can understand that full on rain will be a problem, and that the surface should be dry before you get going. I would of course check the forecast before getting started, but the website advice suggests that which instinct suggests - it can't be the case that every grp roof is made only in summer or under a cover? Are roofers just risking it I wonder? If so how great is the risk? I understand that it cures pretty quickly, so am I right in thinking that all I need is one clear day? Thanks

I suppose the other angle on this is: how weather sensitive is grp in reality? I appreciate that the instruction videos and manufacturers details specify dryness, but with the changeable British weather plenty of folk must get caught out by unforcasted rain. How problematic is that when it happens?

Sounds more expensive than hiring a tent?

Hi My SB is a 100m2 flat roof bungalow for which I intend to use grp. I've tried to program work so as to avoid roofing in the winter but the mortgage company have other ideas it seems, leading me to consider hiring a marquee or tent to bridge over the building and keep rain off whilst roofing. The building is an L shape, and no part of it is wider than 5.5m. Has anyone hired a gazebo or marquee to sit over a roofing project? Any pros and cons based on experience? Ta