Replacing asbestos garage roof

[Roly]

We need to pass some pipes through our corrugated asbestos garage roof, so although for many years we've followed the advice to leave well alone, it makes sense to now get rid of it and replace it with something less scary. The Garage has a flat sloping roof and adjoins the house.

I can find plenty of information about how a DIYer can safely remove and dsipose of the asbestos sheets, but I'm wondering what would be best used to replace it ?

Any suggestions would be welcome. Do building regs influence the choice of materials ? Which materials are most practical ?

[Wiggy]

You would need protective clothing, overalls, goggles, gloves, and a suitable dust mask. Best materialto replace it with would be clear or black corrugated plastic roof sheeting, choose clear depending on how much light you need in you garage, corrugated plastic will be suitable for the job, im pretty sure building regs have no influence on wot type of material you would use for this application, corrugated plastic is probably the cheapest option

[Roly]

Thanks, but as I mentioned, there is no shortage of on-line information about how to safely remove the asbestos, my question is about what to use instead once it's gone.

I'm not looking for the cheapest solution, but neither am I looking to spend a fortune as it's only a garage roof. I'm looking for a neat looking solution that will be durable and practical.

I ought to add that although I call it a garage, like so many others, my car has never seen the inside of it and it's actually a storage place and workshop. It has natural light from glass windows, so the roof doesn't need to let light in.

One more thing is that the roof also covers an adjacent downstairs loo and tiny utility area. ( CH boiler & HW tank ) I assume that building regs don't affect a non-habiltable room like that, but mention it in case there is anything I should bear in mind.

[Phil L]

Asbestos! - you won't put anything up there that will outlive it...seriously though, what are the sheets fastened to now? - if it's angle iron, then plastic isn't rigid enough to cover the same span as rigid asbestos, if it's timber then you can use plastic sheeting, although being so close to the house, this could cause unwanted intrusion from roof tiles etc...so I'd say plywood sheets, bitumen coated, then get a roofer, (or borrow a blowlamp) and cover the lot with green mineral felt, expect 15 years out of it, any more is a bonus

[Roly]

The problem is that new pipes need to be passed through the existing roof and holes from older pipes will need to be made good, so chopping the asbestos around isn't a very attractive proposition. If it weren't for the re-routed pipes, the asbestos would be staying where it is.

The existing roof is supported by timber and it's against a flat end wall of the house that rises well above the line of the garage roof, so tiles won't get in the way.

The two options I had considered were plywood/ felt roof or some sort of metal roofing profile. That's why I was wondering if building regs permit an inflammable material to be used for a garage roof ( although the wooden supports suggest it's OK ). The thing that most concerned me about a metal roof was the prospect of condensation. I didn't want to find out that there was a problem after the job was finished.

Clearly plywood is within the scope of DIY, so it is a serious consideration, but I'd like to know what the alternatives are, what their pros and cons might be and what to avoid.

[Phil L]

How big are the holes for the pipes? - can't the new pipes go through the same holes? - flashband will last for several years plugging small holes up, certainly an option worth considering, if feasible.

I meant falling tiles from above - through plastic.

With metal there almost always is, unless you want to spend a kings ransom on coating it all with celotex.

Plastic goes very brittle after only a few years, but obviously it's cheap...if the walls are up to it, new timbers, battens and roof tiles? - costly but probably the best, although probably less costly than metal / condensation / drip / drip / drip :-p

[Roly]

Due to a bathroom being re-built, the soil pipe needs to be replaced and waste pipes from the shower, bath and sink will need to be relocated too. Whichever way you look at it, some new holes will need to be made and some existing holes will need to be made good. The existing holes through the asbestos roof are prone to leaking anyway, so I'd rather start afresh and have some chance of doing it right.

We had plastic elsewhere previously and it went very brittle indeed. The location does get some pretty serious sun, so it will need to withstand that without going brittle or softening.

[meow2222]

It may be time to ask yourself why there are so many asbestos roofs around. As a roofing material it just cant be beat. All the replacement options mentioned so far wont last a fraction as long, or with metal will give you condensation and heat problems.

I'd keep that roof as long as its ok. If you're really too scared to drill it you can always replace just one panel with something else. You can get fibre cement panels new, which are the same as asbestos but without the absestos in, but they arent cheap. One of thos replacing one existing panel is afaics the only option that will last well and be cheap.

As life's risks go, drilling one hole in your roof is waaaaaaay down the list.

NT

[meow2222]

less risk than going to the shop to get something I reckon.

NT

[nightjar]

A friend of mine is very pleased with heavy duty PVC corrugated sheet. He chose box section, rather than the conventional wavy stuff and, as it comes in up to 6m lengths, there was no need for joints along the length.

Colin Bignell

[Andrew Mawson]

replaced and

relocated

rather

At a practical level, if the asbestos roof is kept wet when you cut it, there should be no significant problem.

AWEM

[Merryterry]

Why not have a look at 'Onduline' sheets. These are the same profile as A/C sheets and are more rigid than PVC. Dont know what they are made of but look OK to me. Last time I saw them were in Wickes

[Roger]

The message from [e-mail] (Roly) contains these words:

What about triple wall polycarbonate sheets typically used for car ports and conservatories?

[Steven Briggs]

In message , Roly writes

Maybe look at commercial metal roofing systems as used for factory units etc. Generally an insulated metal sandwich construction. Would give long life, warmth and no condensation. May well be expensive, but you'd only need a _relatively_ small amount. Any commercial building sites nearby you can bribe the roofers with beer vouchers?

Wards (part of Kingspan now) is a name that springs to mind (only as I pass their factory regularly, and follow wagon loads of the stuff along the A64!)

[The Medway Handyman]

Bitumen Corrugated Sheet